UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Effect of herbicides on proteins in spring wheat Desai, Prabhat Dinkar 1969

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1970_A6_7 D48.pdf [ 10.38MB ]
Metadata
JSON: 831-1.0102104.json
JSON-LD: 831-1.0102104-ld.json
RDF/XML (Pretty): 831-1.0102104-rdf.xml
RDF/JSON: 831-1.0102104-rdf.json
Turtle: 831-1.0102104-turtle.txt
N-Triples: 831-1.0102104-rdf-ntriples.txt
Original Record: 831-1.0102104-source.json
Full Text
831-1.0102104-fulltext.txt
Citation
831-1.0102104.ris

Full Text

EFFECT OF HERBICIDES ON PROTEINS IN SPRING WHEAT by PRABHAT DINKAR DESAI B.Sc. ( A g r i . ) . The U n i v e r s i t y o f Poona 1965 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN-AtSR^eUfcTURE i n t h e Department o f P l a n t S c i e n c e We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA October 1969 In presenting th i s thes i s in pa r t i a l f u l f i lment of the requirements for an advanced degree at the Un ivers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make i t f r ee l y ava i l ab le for reference and study. 1 fur ther agree tha permission for extensive copying of th i s thes i s for scho la r l y purposes may be granted by the Head of my Department or by his representat ives. It is understood that copying or pub l i ca t ion of th i s thes i s f o r f i nanc ia l gain sha l l not be allowed without my wr i t ten permission. Department of P lant Science The Univers i ty of B r i t i s h Columbia Vancouver 8, Canada Date November 25, 1969 ABSTRACT Three v a r i e t i e s o f s p r i n g wheat, S e l k i r k , M a n i t o u and Pembina, were grown i n t h e f i e l d and greenhouse. 2,4--D, b r o m o x y n i l and p i c l o r a m were a p p l i e d a t t h e 6" stage (4 l e a f ) . The e x p e r i m e n t s were c a r r i e d out i n a randomized b l o c k d e s i g n . 2,4-D and p i c l o r a m showed a low c o n c e n t r a t i o n s t i m u l a t i o n and h i g h c o n c e n t r a t i o n i n h i b i t i o n on y i e l d w i t h S e l k i r k . M a n i t o u and Pembina d i d not show d e f i n i t e t r e n d s w i t h t h e s e two h e r b i c i d e s . B r o m o x y n i l d e c r e a s e d t h e y i e l d i n a l l t h r e e v a r i e t i e s and t h e d e c r e a s e was enhanced a t h i g h e r c o n c e n t r a t i o n s . B r o m o x y n i l was t h e o n l y h e r b i c i d e t h a t i n c r e a s e d the p e r c e n t p r o t e i n i n a l l t h r e e v a r i e t i e s . An i n v e r s e r e l a t i o n between t h e p e r c e n t p r o t e i n and y i e l d was seen i n S e l k i r k , M a n i t o u and Pembina t r e a t e d w i t h b r o m o x y n i l . 2,M--D and p i c l o r a m a l s o produced t h i s r e l a t i o n s h i p i n S e l k i r k but not i n M a n i t o u o r Pembina. B r o m o x y n i l s i g n i f i c a n t l y r e d u c e d t h e y i e l d o f p r o t e i n p e r p l o t , whereas 2,4-D and p i c l o r a m d i d n o t . There was no q u a n t i t a t i v e r e l a t i o n between t h e p r o t e i n e x t r a c t e d by 0.1 M T r i s - g l y c i n e b u f f e r (pH 8.3) o r 0.05 N a c e t i c a c i d (pH 3.5) and the p e r c e n t p r o t e i n i n wheat. S e l k i r k was l e a s t a f f e c t e d by any o f the h e r b i c i d e s , i . e . t o t h e changes i n t h e p r o t e i n ( a l b u m i n , g l o b u l i n and g l u t e n ) as seen from t h e d e n s i t o m e t r i c t r a c e s o f g e l s . M a n i t o u and Pembina showed changes as a r e s u l t o f the b r o m o x y n i l t r e a t m e n t . TABLE OF CONTENTS Page I n t r o d u c t i o n 1 Review o f L i t e r a t u r e 3 2 , 4 - D i c h l o r o p h e n o x y a c e t i c A c i d 4 P h o t o s y n t h e s i s 4 R e s p i r a t i o n 5 Phosphorus 7 P r o t e i n 8 N i t r a t e and Amino A c i d s 11 T r a n s l o c a t i o n 13 E f f e c t on C e r e a l s 14 P i c l o r a m 15 B r o m o x y n i l 18 Summary o f L i t e r a t u r e Review 2 0 2 , 4 - D i c h l o r o p h e n o x y a c e t i c A c i d 20 P i c l o r a m 20 B r o m o x y n i l 2 0 M a t e r i a l s and Methods 21 F i e l d T r i a l 21 Pot Experiment 2 2 P e r c e n t N i t r o g e n i n Wheat G r a i n 2 2 E x t r a c t i o n o f Albumins and G l o b u l i n s 2 2 E x t r a c t i o n o f G l u t e n s 2 3 E s t i m a t i o n o f P r o t e i n 2 3 E l e c t r o p h o r e s i s o f S o l u b l e P r o t e i n s E x t r a c t e d w i t h 0.1 M T r i s - g l y c i n e B u f f e r pH 8.3 (Albumins and G l o b u l i n s ) 2 3 P r e p a r a t i o n o f G e l and E l e c t r o p h o r e s i s 24 P o l y m e r i z a t i o n o f t h e G e l 2 5 E l e c t r o p h o r e s i s o f P r o t e i n s E x t r a c t e d w i t h 0.05 N A c e t i c A c i d ( G l u t e n s ) 26 P r e p a r a t i o n o f G e l s and E l e c t r o p h o r e s i s 2 8 S t a i n i n g and D e s t a i n i n g G e l s .2 8 R e c o r d i n g and R e s u l t s 2 9 R e s u l t s 30 Y i e l d 30 P e r c e n t a g e P r o t e i n 3 2 P r o t e i n Y i e l d Per P l o t 32 S o l u b l e P r o t e i n Measured by F o l i n T e s t 34 Zone E l e c t r o p h o r e s i s o f the S o l u b l e P r o t e i n s E x t r a c t e d by 0.1 M T r i s -g l y c i n e B u f f e r pH 8.3 ( A l b u m i n s - G l o b u l i n s ) 36 S e l k i r k 3 6 Ma n i t o u 41 Pembina 41 Zone E l e c t r o p h o r e s i s o f S o l u b l e P r o t e i n s E x t r a c t e d by 0.0 5 N A c e t i c A c i d pH 3.5 ( G l u t e n s ) 42 S e l k i r k 42 Ma n i t o u 46 Pembina 4 6 D i s c u s s i o n 47 C o n c l u s i o n s 51 B i b l i o g r a p h y 5 3 LIST OF TABLES Tab l e 1. The e f f e c t o f h e r b i c i d e s on t h e y i e l d o f wheat 1967 Ta b l e 2. The e f f e c t o f h e r b i c i d e s on the y i e l d o f wheat 1968 T a b l e 3. The e f f e c t o f h e r b i c i d e s on p e r c e n t p r o t e i n o f wheat 1967 T a b l e 4. The e f f e c t o f h e r b i c i d e s on p e r c e n t p r o t e i n o f wheat 19 6 8 T a b l e 5. The e f f e c t o f h e r b i c i d e s on p r o t e i n y i e l d 1967 T a b l e 6. The e f f e c t o f h e r b i c i d e s on p r o t e i n y i e l d 1968 31 31 33 33 35 35 Appendix T a b l e 1 E f f e c t o f h e r b i c i d e s on p e r c e n t p r o t e i n , t o t a l p r o t e i n , and p r o t e i n e x t r a c t e d a t pH 8.3 and pH 3.5. 52 LIST OF FIGURES F i g u r e 1. The d i s c e l e c t r o p h o r e s i s 27 F i g u r e 2. D e n s i t o m e t r i c t r a c e s o f e l e c t r o p h o r e t i c s e p a r a t i o n s o f t h e s o l u b l e p r o t e i n s 3 7 F i g u r e 3. D e n s i t o m e t r i c t r a c e s o f t h e e l e c t r o p h o r e t i c s e p a r a t i o n s o f the s o l u b l e p r o t e i n s ( a l b u m i n s - g l o b u l i n s ) o f whole wheat g r a i n ( v a r . S e l k i r k ) e x t r a c t e d w i t h 0.1 M t r i s -g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n 1\% a c r y l a m i d e g e l s u s i n g t r i s -g l y c i n e b u f f e r , 0.1 M, pH 8 . 3 3 8 F i g u r e 4. D e n s i t o m e t r i c t r a c e s o f the e l e c t r o p h o r e t i c s e p a r a t i o n s o f the s o l u b l e p r o t e i n s ( a l b u m i n s -g l o b u l i n s ) o f whole wheat g r a i n ( v a r . Manitou) e x t r a c t e d w i t h 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n 1\% a c r y l a m i d e g e l s u s i n g t r i s - g l y c i n e b u f f e r , 0.1 M, pH 8.3 39 F i g u r e 5. D e n s i t o m e t r i c t r a c e s o f t h e e l e c t r o p h o r e t i c s e p a r a t i o n s o f the s o l u b l e p r o t e i n s ( a l b u m i n s -g l o b u l i n s ) o f whole wheat g r a i n ( v a r . Pembina) e x t r a c t e d w i t h 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n lh% a c r y l a m i d e g e l s u s i n g t r i s - g l y c i n e b u f f e r , 0.1 M, pH 8.3 40 F i g u r e 6. D e n s i t o m e t r i c t r a c e s o f the e l e c t r o p h o r e t i c s e p a r a t i o n s o f t h e s o l u b l e p r o t e i n s ( g l u t e n s ) o f whole wheat g r a i n ( v a r . S e l k i r k ) e x t r a c t e d w i t h 0.05 N a c e t i c a c i d pH 3.5. E l e c t r o p h o r e s i s i n lh% a c r y l a m i d e g e l s u s i n g a 3 - a l a n i n e -a c e t i c a c i d b u f f e r pH 5.0. 43 F i g u r e 7. D e n s i t o m e t r i c t r a c e s o f t h e e l e c t r o p h o r e t i c s e p a r a t i o n s o f the s o l u b l e p r o t e i n s ( g l u t e n s ) o f whole wheat g r a i n ( v a r . Manitou) e x t r a c t e d w i t h 0.05 N a c e t i c a c i d pH 3.5. E l e c t r o p h o r e s i s i n 1\% a c r y l a m i d e g e l s u s i n g a 3 - a l a n i n e -a c e t i c a c i d b u f f e r pH 5.0. 44 F i g u r e 8. D e n s i t o m e t r i c t r a c e s o f t h e e l e c t r o p h o r e t i c s e p a r a t i o n s o f the s o l u b l e p r o t e i n s ( g l u t e n s ) o f whole wheat g r a i n ( v a r . Pembina) e x t r a c t e d w i t h 0.05 N a c e t i c a c i d pH 3.5. E l e c t r o p h o r e s i s i n 7%% a c r y l a m i d e g e l s u s i n g a 3 - a l a n i n e -a c e t i c a c i d b u f f e r pH 5.0. 45 INTRODUCTION The i n t r o d u c t i o n i n 1944 o f hormone o r growth r e g u l a t i n g t y p e c h e m i c a l s f o r the c o n t r o l o f weeds was a most i m p o r t a n t c o n t r i b u t i o n t o a g r i c u l t u r e . I n t h e p a s t 2 5 y e a r s t h e r e has been an e v e r growing l i s t o f t h e s e h e r b i c i d e s . These m a t e r i a l s have u s u a l l y been i n t r o d u c e d p r i o r t o a b a s i c u n d e r s t a n d i n g o f t h e i r p r e c i s e p h y s i o l o g i c a l and b i o c h e m i c a l e f f e c t s i n t h e l i v i n g p l a n t . T h e i r appearance on the market was, o f c o u r s e , a d i r e c t r e s u l t o f t h e p r e s s u r e which d e v e l o p e d from the f a r m i n g p u b l i c once the e f f e c t i v e n e s s and c o n v e n i e n c e o f t h e m a t e r i a l s had been demonstrated. I n t h e p a s t decade p e o p l e have become more aware o f t h e o v e r a l l e f f e c t s o f p e s t i c i d e s on ecosystems. A l t h o u g h most c o n c e r n i s e x p r e s s e d about the i n s e c t i c i d e s , t h i s o u t l o o k has a l s o b rought a new emphasis i n h e r b i c i d a l r e s e a r c h . S c i e n t i s t s have t r i e d t o d e t e r m i n e the b a s i c cause and e f f e c t r e l a t i o n s h i p s o f t h e s e c h e m i c a l s i n p l a n t s and a s s o c i a t e d components o f t h e environment. I t i s becoming i n c r e a s i n g l y e v i d e n t t h a t hormones do not r e a c t s i n g l y , but r a t h e r i n an i n t e r r e l a t e d manner i n t h e p l a n t . Thus, the v a r i o u s p l a n t hormones p r e s e n t w i l l v a r y i n t h e i r e f f e c t s on t h e growth and u l t i m a t e f a t e o f a t i s s u e depending on t h e amounts o f each type p r e s e n t . I n t h e l i t e r a t u r e many enzymes and p h y s i o l o g i c a l systems have - 2 -been suggested as the key factor i n the hormonal control of growth. Lethal concentrations of growth regulator type herbicides have been shown to cause tissue p r o l i f e r a t i o n , decrease i n photosynthetic rate, increase i n r e s p i r a t i o n , depletion of reserve carbohydrates and increases i n protein and RNA. Galston, i n his recent a r t i c l e "Hormonal Regulation i n Higher Plants" (32), says, "It now appears that a p a r t i a l answer to the action of plant and animal hormones l i e s i n the control of the mechanism by which enzymes are made in the c e l l , that i s , somewhere i n the genetic information of the c e l l , which determines i t s ultimate p o t e n t i a l , the mess-enger RNA which s p e c i f i e s protein to be made, or the protein synthesizing machinery involving the ribosomes and transfer RNA." It appears that the general protein synthesis may be affected rather than any single process through which a p a r t i c u l a r protein i s being triggered . "on" or " o f f " . M i l l i o n s of acres of wheat, at various stages of growth, are sprayed annually with the herbicides. Numerous reports i n the l i t e r a t u r e have shown that the wheat kernels from treated plants seem to have a higher protein percentage than t h e i r untreated counterpart. The study reported here was an attempt to determine some of the changes which occur i n the proteins of the wheat kernel when the plants are treated with herbicides. - 3 -REVIEW OF LITERATURE Any h e r b i c i d e which e n t e r s p l a n t t i s s u e i s i n f a c t a " f o r e i g n " m o l e c u l e and i t s f a t e w i t h i n t he t i s s u e w i l l depend upon i t s p h y s i c a l and c h e m i c a l p r o p e r t i e s . H e r b i c i d e s o r t h e i r r e a c t i o n p r o d u c t s a r e s t a b l e and m o b i l e i n t h e p l a n t t i s s u e . I f t h e m o l e c u l e p e r se i s t o p e r s i s t i n t h e p l a n t i t must p o s s e s s a degree o f r e s i s t a n c e t o breakdown o r d e t o x i f i c a t i o n . Such a breakdown p r o c e s s would presumably be brought about by enzymes. Three h e r b i c i d e s were used i n the p r e s e n t s t u d y . The s t r u c t u r a l f o r m u l a e a l o n g w i t h i n d o l e a c e t i c a c i d , an a u x i n , a r e shown below: H CI ^ ^ O - C - C O O H CI 2,4-Dichlorophenoxy-A c e t i c A c i d I n d o l e A c e t i c A c i d Br CN-Br OH H-N-H CI C I N CI ^ v C O O H 3,5-Dibromo-4 Hydroxy-B e n z o n i t r i l e ( B r o m o x y n i l ) 4-Amino-3,5,6 T r i c h l o r o -P i c o l i n i c A c i d ( P i c l o r a m ) - 4 -2 , 4 - D i c h l o r o p h e n o x y a c e t i c A c i d  P h o t o s y n t h e s i s One hundred ppm o f 2,4-D a p p l i e d as a s p r a y t o bean l e a v e s was found t o reduce the p h o t o s y n t h e t i c r a t e by 2 0% (2 4 , 2 5 ) . W i l l i a m and Dunn (101) found t h a t exposure o f p l a n t s t o b l u e l i g h t f o l l o w i n g the a p p l i c a t i o n o f 2,4-D was e f f e c t i v e i n r e d u c i n g 2,4-D i n t e r f e r e n c e w i t h CO2 u t i l i z a t i o n . Under r e d l i g h t , t h e 2,4-D t r e a t e d mustard p l a n t s had low c h l o r o p h y l l c o n t e n t . I n t h e l a t t e r case the lowered d r y weight c o u l d be a t t r i b u t e d t o low c h l o r o p h y l l c o n t e n t r a t h e r t h a n t o a d e t r i m e n t a l e f f e c t on the photo-s y n t h e t i c r a t e . A low r a t e o f 2,4-D (0.001%) a p p l i e d t o v e l v e t bean S t i z o l o b i u m d e e r i n g i a n u m s e e d l i n g s had no e f f e c t on p h o t o s y n t h e s i s f o r 7 days f o l l o w i n g a p p l i c a t i o n . However a t h i g h e r r a t e s ( 0 . 0 1 % ) , t h e decrease was n o t i c e a b l e as e a r l y as f i v e hours a f t e r t r e a t m e n t . The h i g h e r dosage r e s u l t e d i n damage b o t h t o the m e s o p h y l l and t o the stem phloem and thus c o n t r i b u t e d t o a d e c r e a s e d p h o t o s y n t h e t i c r a t e ( 6 2 ) . I n h i b i t i o n o f p h o t o s y n t h e s i s was r e l a t e d t o the c o n c e n t r a t i o n o f u n d i s s o c i a t e d 2,4-D m o l e c u l e s ( 8 ) . The p h o t o s y n t h e t i c r a t e s o f s u n f l o w e r and o a t s , a s u s c e p t i b l e and a r e s i s t a n t s p e c i e s r e s p e c t i v e l y , d e c r e a s e d 27 and 64% a f t e r 2,4-D (0.15%) t r e a t m e n t . A week l a t e r the o a t s showed r e c o v e r y whereas no n o t i c e a b l e change o c c u r r e d i n t h e s u n f l o w e r s ( 7 7 ) . - 5 -R e s p i r a t i o n The r a p i d d e p l e t i o n o f s t a r c h and sugar i n a wide v a r i e t y o f p l a n t s i s a v e r y common r e s u l t o f t r e a t m e n t w i t h a u x i n s . S e l l e t a l . (86) n o t i c e d d e p l e t i o n o f r e d u c i n g and n o n - r e d u c i n g s u g a r and r e d u c t i o n i n s t a r c h , crude f i b r e and a c i d h y d r o l y z a b l e p o l y s a c c h a r i d e s i n l e a v e s . I n r e d k i d n e y bean r o o t s t h e r e was a d e p l e t i o n o f n o n - r e d u c i n g sugars and no change i n r e d u c i n g s u g a r s , s t a r c h p o l y s a c c h a r i d e s o r crude f i b r e f o l l o w i n g t h e a p p l i c a t i o n o f 1,0 00 ppm o f 2,4-D. Wort (103) a p p l i e d v a r i o u s c o n c e n t r a t i o n s o f 2,4-D (50-1,000 ppm) t o buckwheat p l a n t s about one f o o t h i g h and found t h a t the t o t a l s u g a r c o n t e n t o f stem and l e a v e s i n c r e a s e d w i t h i n a day a f t e r t r e a t m e n t . However, by t h e 8th day t h e c o n t e n t had f a l l e n t o 48% o f t h e c o n t r o l . The sugar c o n t e n t o f t h e buckwheat r o o t s d i m i n i s h e d s t e a d i l y . Smith's (90) r e v i e w on r e s p i r a t i o n changes i n r e l a t i o n t o t o x i c i t y i n d i c a t e d t h a t t h e 2,4-D e x e r t s i t s i n f l u e n c e on t h e a e r o b i c phase o f r e s p i r a t i o n o f b a c t e r i a and h i g h e r p l a n t s . L i n d e n (59) s u g g e s t e d t h a t 2,4-D b r i n g s about i n c r e a s e s i n r e s p i r a t o r y r a t e by a f f e c t i n g t h e phosphate m e t a b o l i s m and by u n i o n w i t h m e t a b o l i c p r o d u c t s o f enzymes. 2,4-D has a g r e a t e r i n h i b i t o r y e f f e c t on p h o s p h o r y l a t i o n t h a n on r e s p i r a t i o n (60). S w i t z e r (93) d i s c e r n e d t h a t 2,4-D and 2,4,5-T i n h i b i t e d b o t h 0 2 and _5 phosphorus uptake a t 5 x 10 M. Oxygen uptake was changed a p p r o x i m a t e l y t h e same amount i n t h e p r e s ence o f i n t e r m e d i a t e s o f t h e Kreb's c y c l e , i n d i c a t i n g t h a t t h e whole enzyme complex - 6 -was a f f e c t e d r a t h e r t h a n one p a r t i c u l a r enzyme system. The c o n c e n t r a t i o n o f i n o r g a n i c phosphorus i n t h e r e a c t i o n v e s s e l was i n c r e a s e d by 2,4-D. Thus, i t was q u i t e p o s s i b l e t h a t 2,4-D a c t e d as an u n c o u p l i n g agent. Wedding and B l a c k (9 8) 32 found t h a t i n c o r p o r a t i o n o f P i n t o a d enosine t r i p h o s p h a t e (ATP)and adenosine d i p h o s p h a t e (ADP)in C h l o r e l l a was i n h i b i t e d by 2,4-D. C o n c e n t r a t i o n s t h a t i n h i b i t i n c o r p o r a t i o n i n t o n u c l e o t i d e s s t i m u l a t e d the uptake o f oxygen. T h i s a g a i n s u g g e s t s t h a t 2,4-D e f f e c t i v e l y u n c o u p l e s p h o s p h o r y l a t i o n . That a u x i n s i n f l u e n c e p h o s p h o r y l a t i o n and the p r o d u c t i o n o f a denosine t r i p h o s p h a t e and t h r o u g h t h i s l a t t e r compound a f f e c t t h e energy a v a i l a b l e f o r a l a r g e number o f r e a c t i o n s was s u g g e sted by Bonner and B a n d u r s k i (6) and S w i t z e r ( 9 3 ) . Working w i t h C - l , C-2 and C-6 l a b e l l e d g l u c o s e , Humphreys and Dugger (44) showed t h a t most c a t a b o l i s m o f g l u c o s e was a c c o m p l i s h e d t h r o u g h th e pentose phosphate pathway. T h i s i n d i c a t e s t h a t 2,4-D may change t h e r e l a t i v e i m p o r t a n c e o f t h e g l y c o l y t i c pathway t o cause a f a v o u r i n g o f t h e pentose phosphate pathway. 2,4-D r e s u l t e d i n a g e n e r a l i n c r e a s e i n a c t i v i t y o f the enzymes a s s o c i a t e d w i t h t h e pentose phosphate c y c l e o f e t i o l a t e d c o r n s e e d l i n g s . 2,4-D, 2,4,5-T and 2,4,6-T a t 10 M r e d u c e d th e i n c o r p o r a t i o n o f g l u c o s e i n t o t h e c e l l w a l l , o n l y s l i g h t l y a f f e c t e d i t s o x i d a t i o n t o C 0 2 and i n c r e a s e d i t s i n c o r p o r a t i o n i n t o a l c o h o l s o l u b l e i n t e r m e d i a t e s ( 5 ) . - 7 -Phosphorus Phosphorus i s endowed w i t h a s p e c i a l i m p o r t a n c e because o f t h e u b i q u i t o u s r o l e o f phosphate and p h o s p h o r y l a t i o n i n many m e t a b o l i c p r o c e s s e s — p h o t o s y n t h e s i s , r e s p i r a t i o n , n u c l e o t i d e f o r m a t i o n , g e n e r a t i o n o f h i g h energy bonds, p r o t e i n s y n t h e s i s and c a r b o h y d r a t e i n t e r c o n v e r s i o n t o mention a few. Root a p p l i c a t i o n s o f 0.01-10 ppm 2,4-D t o soybean caused a d e c r e a s e d uptake o f phosphate (2 6 ,102).' However, an a p p r e c i a b l e i n c r e a s e i n phosphate uptake was n o t e d when a 2,000 ppm 2,4-D s o l u t i o n was a p p l i e d t o tomato t o p s ( 8 2 ) . I n o r g a n i c phosphorus i n c r e a s e d i n l e a v e s o f p l a n t s t r e a t e d w i t h 2,4-D (0.1%) but t h a t was t h e o n l y f r a c t i o n w hich d e c r e a s e d i n t h e stems ( 1 9 ) . Ormrod and W i l l i a m s (70) showed an i n c r e a s e i n a c i d s o l u b l e o r g a n i c phosphate and a c o n c u r r e n t d e c r e a s e i n i n o r g a n i c phosphate as e a r l y as one minute a f t e r 50 micrograms 2,4-D was a p p l i e d t o the l e a v e s o f a c l o v e r p l a n t . Rebstock e t a l _ . (79) showed t h a t 1,000 ppm 2,4-D i n c r e a s e d t h e n u c l e i c a c i d phosphorus i n t h e whole bean p l a n t , w h i l e t h e n u c l e i c a c i d i t s e l f d o u b l e d . I n c o r p o r a t i o n o f P 3 2 i n t o ATP and ADP i s reduced by about 30% and 75% -4 -5 w i t h 10 and 10 M 2,4-D r e s p e c t i v e l y . I n h i b i t i o n o f c h e l a t e s t i m u l a t i n g adenosine t r i p h o s p h a t a s e and o f t h e ATP: 32 P exchange r e a c t i o n by 2,4-D i n d i c a t e t h a t 2,4-D p r o b a b l y i n t e r f e r e s w i t h one o r more o f the r e a c t i o n s which c o u p l e the p h o s p h o r y l a t i o n o f ADP w i t h e l e c t r o n t r a n s p o r t ( 9 8 ) . - 8 -P r o t e i n H e r b i c i d a l c o n c e n t r a t i o n s o f 2,4-D i n c r e a s e d the p r o t e i n and RNA c o n t e n t o f t h e stem t i s s u e o f cucumbers w h i l e low c o n c e n t r a t i o n s o f 2,4-D i n c r e a s e d the. d r y w e i g h t but r e s u l t e d i n d e c r e a s e d RNA ( 1 0 0 ) . B a s l e r and Nakazawa (3) found t h a t h i g h c o n c e n t r a t i o n s o f 2,4-D r e s u l t e d i n a h i g h c o n t e n t o f b o t h s o l u b l e and p a r t i c u l a t e p r o t e i n . RNA s y n t h e s i s was i n c r e a s e d and t h e l o c a t i o n o f n u c l e i c a c i d w i t h i n t h e c e l l components was a l t e r e d i n c o t t o n s e e d l i n g s c u l t u r e d i n s o l u t i o n s c o n t a i n i n g 2,4-D. -4 An a p p l i c a t i o n o f 15 ml o f 5 x 10 M 2,4-D d o u b l e d t h e RNA c o n t e n t i n 24-48 hours i n bean s e e d l i n g s . The i n c r e a s e d i d n o t seem t o c o r r e s p o n d t o t h e c y t o p l a s m i c i n c r e a s e . Ten hour exposures o f soybean h y p o c o t y l t o 10 ppm o f 2,4-D m a i n t a i n e d o r i n c r e a s e d t h e l e v e l o f RNA and enhanced t h e 14 a b s o r p t i o n o f ADP -C . F i v e hundred ppm o f 2,4-D i n h i b i t e d 14 the a b s o r p t i o n o f ADP-C and i t s i n c o r p o r a t i o n i n t o RNA. ATP c o n t e n t had i n c r e a s e d 45% i n 3 hours and was m a i n t a i n e d f o r a s h o r t p e r i o d . The i n c r e a s e o f ATP was not a s s o c i a t e d w i t h a de c r e a s e i n AMP and ADP ( 4 5 ) . C h r i s p e e l s and Hanson (11) a l s o found t h a t the RNA c o n t e n t was doubled i n 4 8 hours w i t h o v e r h a l f o f t h e i n c r e a s e a p p e a r i n g i n t h e m i c r o s o m a l f r a c t i o n and a q u a r t e r i n the s o l u b l e f r a c t i o n . Key (46) noted a n e t l o s s o f 20 and 50% o f RNA from 0.5 and 10 ppm 2,4-D r e s p e c t i v e l y , whereas t h e r e was o n l y 5 - 9 -and 10% d e c r e a s e i n RNA w i t h 500 and 800 ppm 2,4-D. RNA l o s s a t 5 ppm was i n i t i a t e d d u r i n g t h e f i r s t f o u r hours and t h e l o s s i n c r e a s e d w i t h t i m e . A t 5 00 ppm 2,4-D t h e RNA l o s s proceeded a t normal r a t e s f o r 12 h o u r s . At a l o w e r c o n c e n t r a t i o n 14 o f 2,4-D C adenosine was i n c o r p o r a t e d i n d i c a t i n g a c t i v e s y n t h e s i s o f RNA even though t h e r e was a net l o s s o f RNA, whereas a t h i g h e r c o n c e n t r a t i o n s t h e i n c o r p o r a t i o n was d e c r e a s e d by 74.4%. L a t e r Key and Shannon (47) a l s o c o n f i r m e d t h e l a t e r e x p e r i m e n t s . Key (46) su g g e s t e d t h a t t h e r o l e o f a u x i n (2,4-D) i n a l t e r i n g RNA m e t a b o l i s m i s a s s o c i a t e d p r i m a r i l y w i t h m e t a b o l i c breakdown o f RNA and not s y n t h e s i s . A c t i v e RNA s y n t h e s i s , and i n t u r n p r o t e i n s y n t h e s i s , i s r e q u i r e d f o r the enhanced r a t e o f c e l l e l o n g a t i o n by 2,4-D. Presumably t h e r a t e o f f o r m a t i o n o f some s p e c i f i c RNA i s enhanced so as t o have an i n c r e a s e d s u p p l y o f some l i m i t i n g enzyme o r enzyme systems ( 4 8 ) . Key and Shannon (47) found a 25-30% n e t i n c r e a s e i n t o t a l RNA, p r i m a r i l y r i b o s o m a l , i n IAA and 2,4-D t r e a t e d 14 soybean h y p o c o t y l . Time c o u r s e s t u d i e s w i t h C n u c l e o t i d e 14 i n c o r p o r a t i o n i n t o RNA i n d i c a t e a n e t t r a n s f e r o f C RNA from t h e n u c l e u s t o t h e r i b o s o m e s . A c t i n o m y c i n D i n h i b i t e d t h e s y n t h e s i s o f RNA ( 3 ) . A c t i n o m y c i n D and azaguanine almost c o m p l e t e l y b l o c k e d IAA i n d u c e d growth i n a r t i c h o k e t u b e r s when added s i m u l t a n e o u s l y , but had no e f f e c t when added 24 hours a f t e r IAA ( 6 8 ) . - 10 -Shannon e t a l _ . (87) noted t h a t low c o n c e n t r a t i o n s o f 2,4-D a c c e n t u a t e d growth and r i b o n u c l e a s e a c t i v i t y . On t h e o t h e r hand h i g h c o n c e n t r a t i o n s o f 2,4-D i n h i b i t e d growth and t h e development o f r i b o n u c l e a s e a c t i v i t y . H y b r i d i z a t i o n s t u d i e s w i t h pea showed t h a t t h e RNA s y n t h e s i z e d as a r e s u l t o f a u x i n a p p l i c a t i o n c o n s i s t e d t o a s m a l l e x t e n t o f a messenger RNA f r a c t i o n , w h i c h was i n low c o n c e n t r a t i o n i n u n t r e a t e d t i s s u e , a n d o f t h e polysome RNA. T h i s s t i m u l a t e d RNA f o r m a t i o n f i r s t o c c u r r e d i n t h e n u c l e u s and l a t e r i n t h e c y t o p l a s m ( 9 4 , 9 5 ) . Nooden (68) found t h a t IAA had a v e r y l a r g e and a 3 2 v e r y r a p i d s t i m u l a t o r y e f f e c t i n i n c o r p o r a t i o n o f P o r t h o p h o s p h a t e i n t o RNA i n d i s k s . No d e t e c t a b l e change i n base c o m p o s i t i o n i n t h e RNA s y n t h e s i z e d was n o t i c e d . DNA s y n t h e s i s has been r e p o r t e d t o be s u p p r e s s e d by t h e a p p l i c a t i o n o f 2,4-D (1.25 x 10~^M) t o peanut c o t y l e d o n s measured by t h e 3 2 i n c o r p o r a t i o n o f P ( 1 0 ) . The l a t t e r a u t h o r s s u g g e s t e d t h a t DNA polymerase i n h i b i t i o n may be the m o l e c u l a r b a s i s o f h e r b i c i d a l a c t i o n . Schwinner (8 5) a l s o found t h a t 2,4-D and IAA i n h i b i t e d DNA s y n t h e s i s i n a c e l l f r e e system o f pea w i t h E. c o l i DNA polymerase. Ray and Ruesink (78) showed a t e m p e r a t u r e dependent l a g phase between a u x i n a p p l i c a t i o n and t h e r e s u l t i n g growth r e s p o n s e . T h i s i n d i c a t e d t h a t t h e a u x i n may not a c t d i r e c t l y - l i -on growth, but on some p r o c e s s which l a t e r a l t e r s t h e growth r a t e . T h i s i n t e r m e d i a t e p r o c e s s has been shown t o be s e n s i t i v e t o i n h i b i t o r s o f p r o t e i n and RNA s y n t h e s i s , s u g g e s t i n g t h e n e c e s s i t y o f p r o t e i n and RNA s y n t h e s i s f o r a u x i n a c t i o n . There i s a p a r a l l e l between t h e i n h i b i t i o n o f growth and 14 p r o t e i n s y n t h e s i s as measured by i n c o r p o r a t i o n o f C l a b e l l e d amino a c i d s ( 6 1 ) . N i t r a t e and Amino A c i d s P r o t e i n c o n t e n t d o u b l e d i n s i x days a f t e r a p p l i c a t i o n o f 0.05 ml o f 1,000 ppm 2,4-D t o bean l e a v e s ; t h e i n c r e a s e was e v i d e n t l y a t t h e expense o f t h e c a r b o h y d r a t e . A r g i n i n e , h i s t i d i n e , i s o l e u c i n e , p h e n y l a l a n i n e and v a l i n e i n c r e a s e d o n l y s l i g h t l y whereas l y s i n e and m e t h i o n i n e t r e b l e d ( 8 6 ) . A s i g n i f i c a n t i n c r e a s e i n amino a c i d and p r o t e i n was found i n r o o t s o f Canada t h i s t l e t r e a t e d w i t h low c o n c e n t r a t i o n s o f 2,4-D ( 1 0 4 ) . Bean p l a n t s t r e a t e d w i t h 2,4-D showed r e d u c t i o n s o f amino a c i d s and p r o t e i n o f r o o t s and l e a v e s , whereas an i n c r e a s e i n t h e stem was a t t r i b u t e d t o t r a n s l o c a t i o n ( 9 9 ) . Such a movement d i d not o c c u r from r o o t s i n buckwheat ( 1 0 3 ) . No change i n n i t r a t e c o n t e n t was n o t i c e a b l e i n t u b e r s o f p l a n t s t r e a t e d w i t h 2,4-D ( 3 1 ) . Soybean p l a n t s were exposed f o r 2 5 hours i n n u t r i e n t s o l u t i o n c o n t a i n i n g 2,4-D (5 ppm). W h i l e t h e r e was no e f f e c t on n i t r a t e accumul-a t i o n o r t h e t o t a l n i t r o g e n c o n t e n t o f the soybean p l a n t , t h e n i t r o g e n d i s t r i b u t i o n was q u i t e markedly a f f e c t e d . There was a s l i g h t r e d u c t i o n o f n i t r a t e i n soybeans t r e a t e d w i t h 2,4-D - 12 -a t 4 l b / a c r e ( 2 7 ) . Swanson and Shaw (92) found t h a t w i t h Sudan g r a s s t h e r e was an i n i t i a l r i s e i n n i t r a t e f o l l o w e d by a f a l l , a g a i n f o l l o w e d by a r i s e 8 days a f t e r t r e a t m e n t . The h y d r o c y a n i c a c i d c o n t e n t behaved e x a c t l y the o p p o s i t e . Frank and B r i s b y (22) a l s o found a n i t r a t e i n c r e a s e i n Eup a t o r i u m maculatum and Im p a t i e n s b i f l o r a ^ " a f t e r t r e a t m e n t w i t h 2,4-D. Both 2,4-D and m a l e i c h y d r a z i d e , s i n g l y o r t o g e t h e r , a l t e r t h e e l e c t r o p h o r e t i c p a t t e r n o f p r o t e i n , s h i f t i n g the main f r a c t i o n o f p o t a t o t i p s and t u b e r s towards the anode, w h i l e t h a t o f bean t o p moved toward t h e cathode ( 1 0 5 ) . 14 Osborne and Ha l l a w a y showed t h a t t h e i n c o r p o r a t i o n o f C l e u c i n e , an i n d i c a t i o n o f p r o t e i n s y n t h e s i s , was m a i n t a i n e d by e x c i s e d l e a v e s o f prunes t r e a t e d w i t h 2,4-D, whereas t h e r e was a 6 0% de c r e a s e i n the c o n t r o l ( 7 2 ) . Hay and Thimann (38,39) found t h a t f r e e l y e x t r a c t -a b l e 2,4-D r a p i d l y d i s a p p e a r s i n t h e p l a n t . T h i s l o s s o f 2,4-D was f a s t e r i n l i g h t . T r a n s p o r t o f 2,4-D c o u l d n o t be e x p l a i n e d by the mass f l o w h y p o t h e s i s , but i n v o l v e s a m e t a b o l i c movement. C o t t o n d e c a r b o x y l a t e d t h e s i d e c h a i n o f 2,4-D s e v e r a l t i m e s f a s t e r t h a n a r e s i s t a n t p l a n t l i k e sorghum. A f t e r c o t t o n r e c o v e r e d , t h e growth r e g u l a t o r c o u l d n o t be d e t e c t e d i n subsequent v e g e t a t i v e o r r e p r o d u c t i v e growth ( 6 7 ) . B a s l e r (4) showed t h a t the r a t i o s o f d e c a r b o s y l a t i o n were a p p a r e n t l y n o t c o r r e l a t e d w i t h s u s c e p t i b i l i t y . The 2,4-D s t i m u l u s p e r s i s t e d i n t h e c o t t o n seed and r e g r o w t h l e a v e s when - 13 -the p l a n t was t r e a t e d w i t h 2,4-D a l o n g w i t h a d e s i c c a n t ( 1 3 ) . I n bean h y p o c o t y l 2,4-D a f f e c t e d t i s s u e e x t e r i o r t o t h e cambium and f i n a l l y d e s t r o y e d t h e phloem ( 1 7 ) . The average c e l l l e n g t h o f t r e a t e d r a d i c l e s was l e s s t h a n the c o n t r o l s , i . e . , 27.5 m i c r o n s t o 47.7 microns r e s p e c t i v e l y . The t o t a l number o f c e l l s was h i g h e r i n t r e a t e d and o l d e r r a d i c l e s o f the same l e n g t h , s u g g e s t i n g t h a t the 2,4-D (1,000 ppm) i n h i b i t e d e l o n g a t i o n , b u t not c e l l d i v i s i o n ( 8 4 ) . C e l l s o f mature r o o t s , a f t e r t r e a t m e n t w i t h 2,4-D, showed s w e l l i n g and t h e n began t o d i v i d e r a p i d l y ( 3 3 ) . I n i t i a l l y , t h e r e was a minor d e t e r i o r a t i o n o f t h e c o r t i c a l c e l l s f o l l o w e d by more s e v e r e d e s t r u c t i o n o f t h e s e c e l l s , and t h e n th e endodermis and exodermis areas were g e n e r a l l y a f f e c t e d . T h i s was a g a i n f o l l o w e d by a complete d e g e n e r a t i o n o f the c o r t e x , p e r i c y c l e and cambium ( 5 4 ) . The e s t e r o f 2,4-D caused 0.42% a b e r r a n t c e l l s i n sorghum and 2,4-D amine caused 0.17% p o l y p l o i d y ( 1 2 ) . T r a n s l o c a t i o n Cookie n o t i c e d t h a t a p p l i c a t i o n s o f 2,4-D t o t h e f o l i a g e o f beans r e s u l t e d i n an i n i t i a l i n c r e a s e i n t h e uptake o f n u t r i e n t s from the s o i l ( 1 2 ) . 2,4-D i s r a p i d l y degraded d u r i n g p e n e t r a t i o n , t h e CO2 b e i n g i m m e d i a t e l y s y n t h e s i z e d t o sugars and amino a c i d s i n b a r l e y ( 1 4 ) . - 14 -P r e t r e a t m e n t o f k i d n e y bean w i t h g i b r e l l i n 4 8 hours b e f o r e 2,4-D a p p l i c a t i o n i n c r e a s e d t h e amount o f 2,4-D found i n t h e u n t r e a t e d a r e a s i n t h e f i r s t 24 hours ( 1 ) . The d i s t r i b u t i o n o f 2,4-D became c o m p l e t e l y s y s t e m i c i n cucumber p l a n t s i n 24 h o u r s , and changed l i t t l e by the end o f 8 days. However, 2,4,5-T t r a n s l o c a t i o n c o n t i n u e d t o change d u r i n g the 8 day p e r i o d . S e v e n t y - f i v e p e r c e n t o f t h e 2,4-D was found as two m e t a b o l i t e s w i t h i n 24 h o u r s , whereas 2,4,5-T formed o n l y t r a c e s o f t h e s e i n 8 days ( 8 9 ) . Leonard e t a l _ . (57) found t h a t h i g h c o n c e n t r a t i o n s o f 2,4-D and p i c l o r a m slowed the 14 downward movement o f C a s s i m i l a t e s i n f i e l d grown v i n e s . The e f f e c t was g r e a t e r w i t h p i c l o r a m t h a n 2,4-D. E f f e c t on C e r e a l s 2,4-D t r e a t e d wheat which was weed f r e e produced l o w e r y i e l d s t h a n t h e c o n t r o l s , p a r t i c u l a r l y when the wheat was s p r a y e d i n t h e d i f f e r e n t i a t i n g s t a g e . The r e d u c e d y i e l d was m a i n l y due t o t h e p r o d u c t i o n o f s t e r i l e heads. However, the g r e a t e s t a b n o r m a l i t i e s o c c u r r e d i n p l a n t s s p r a y e d a t o r b e f o r e t h e j o i n t i n g s t a g e ( 5 1 ) . There i s a r e l a t i o n s h i p between th e a p i c a l development s t a g e and t h e number o f l e a v e s on t h e p l a n t . T h i s r e l a t i o n s h i p i s i n v a l u a b l e i n e s t a b l i s h i n g grower recommendations i n t h a t the l e a f number i s a u s e f u l i n d i c a t i o n o f the s u s c e p t i b i l i t y o r s a f e t y t o 2,4-D ( 6 3 ) . The p r o t e i n c o n t e n t o f seven v a r i e t i e s o f wheat i n c r e a s e d i n d i r e c t r e l a t i o n t o t h e amount o f 2,4-D a p p l i e d , r e g a r d l e s s o f d e c r e a s e s o r i n c r e a s e s i n g r a i n s t r a w y i e l d ( 1 8 ) . - 15 -2,4-D tended t o i n c r e a s e t h e n i t r o g e n c o n t e n t o f t h e wheat g r a i n e x p r e s s e d as a p e r c e n t o f t h e d r y w e i g h t w i t h a p a r a l l e l r e duced y i e l d ( 30,52). Y i e l d , r e d u c t i o n s o f up t o 10% r e s u l t e d from 2,4-D t r e a t m e n t a t 1 l b / a c r e ( 5 2 ) . E a r l y 2,4-D t r e a t m e n t i n sorghum reduced, the y i e l d s , but a l l t h e v a r i e t i e s d i d not r e a c h the most s u s c e p t i b l e s t a g e o f growth s i m u l t a n e o u s l y . Twenty p e r c e n t o f the y i e l d r e d u c t i o n was brought about by the use o f 2,4-D amine a p p l i e d a t t h e f o u r t o s i x l e a f s t a g e ( 3 7 ) . I n a n o t h e r r e p o r t , 2,4-D a t 0.5 - 1 l b / a c r e reduced the y i e l d o f sorghum t r e a t e d a t t h e 9-11 l e a f s t a g e ( 7 4 ) . S p i k e i n i t i a t i o n was t h e most s e n s i t i v e s t a g e t o 2,4-D and t h e most r e s i s t a n t phase f o l l o w e d s p i k e d i f f e r e n t i a t i o n . N i n e t e e n p e r c e n t and t h i r t y - f o u r p e r c e n t r e d u c t i o n s o f y i e l d were n o t i c e d a t low and h i g h c o n c e n t r a t i o n o f 2,4-D r e s p e c t i v e l y ( 7 6 ) . P h i l l i p s e t a l . (75) found no e f f e c t on y i e l d , c h e m i c a l c o m p o s i t i o n , m i l l i n g o r b a k i n g q u a l i t y o f wheat when spr a y e d w i t h 2,4-D a t 21, 14 and 7 days b e f o r e h a r v e s t i n g . I n o t h e r r e p o r t s i n c r e a s e s i n the p e r c e n t a g e p r o t e i n i n wheat and b a r l e y g r a i n have been found f o l l o w i n g a p p l i c a t i o n o f 2,4-D and i n t h e s e c a s e s , i n c r e a s e s were r e a l f o r no r e d u c t i o n i n y i e l d o c c u r r e d (16,104). P i c l o r a m P i c l o r a m , a s y s t e m i c h e r b i c i d e , i s r e a d i l y t r a n s -l o c a t e d t o the r o o t s , u s u a l l y c a u s i n g c u r l i n g o f the new - 16 -tender tissue and epinasty of the leaves (83). Radioactive picloram i s transported as an i n t a c t molecule through sections of bean petioles (43). V i s i b l e symptoms are slower to appear i n picloram treated cucumber and bean than 2,4-D or 2,4,5-T treated plants. It was also found that the rhizome pieces of Milkweed (Asclepias syriaca) treated with picloram alone or i n mixtures with 2,4,5-T were k i l l e d , whereas rhizomes from 2,4,5-T treated plants were viable. The authors suggested that the delayed action might f a c i l i t a t e the movement of the compound into the below ground parts (53). Hamaker e_t aJL. observed that picloram produces destruction of growing tissue and curvature of leaves and stems (15). F o l i a r treatment with picloram induced rapid procambium a c t i v i t y i n western ironweed (Vernonia baldwinii). Increased meristematic a c t i v i t y was followed by destruction of phloem parenchyma, sieve elements and companion c e l l s (85). No v i s i b l e damage was noticed on leaves of Canada t h i s t l e sprayed with picloram, but seven days a f t e r treatment roots from the treated plants showed p a r t i a l disorganization of c o r t i c a l c e l l s followed by a complete breakdown of c o r t i c a l tissue i n 14 days. Twenty-five days a f t e r treatment the t h i s t l e cambium and phloem tissues showed complete disintegration (56). Davis et a l . (15) found that the a c t i v i t y of maleic dehydrogenase was i n h i b i t e d by picloram i n mesquite (Prosopis  j u l i f l o r a ) . This i n h i b i t i o n was overcome by the oxidized and - 17 -reduced forms o f n i c o t i n e adenine d i n u c l e o t i d e phosphate (NADP) and had a n o n - c o m p e t i t i v e r e l a t i o n s h i p t o o x a l o -a c e t a t e and m a l a t e . I n h i b i t i o n o f s u c c i n i c dehydrogenase o c c u r s w i t h i n c r e a s i n g c o n c e n t r a t i o n o f p i c l o r a m . Reddman (80) showed t h a t 8% o x a l i c a c i d i s formed due t o m e t a b o l i s m o f p i c l o r a m i n wheat, but i n no way was t h i s t h e o n l y cause o f t h e d e a t h o f a t i s s u e . He a l s o n o t i c e d r a d i o a c t i v i t y i n a l l p a r t s o f 5 week o l d wheat p l a n t s grown i n s o i l t r e a t e d w i t h r a d i o a c t i v e p i c l o r a m . A p p l i c a t i o n o f 3/8 t o lh oz o f p i c l o r a m p e r a c r e d i d not reduce th e y i e l d o f wheat ( 5 5 ) . P i c l o r a m a t 3 l b s / a c r e caused s e v e r e l e a f m o d i f i c a t i o n s and s t u n t i n g o f w a t e r -melons and t r a n s p l a n t e d tomatoes 12 months a f t e r s p r a y i n g but had no e f f e c t s on sweet c o r n . No v i s i b l e abnormal symptoms were seen on any s p e c i e s p l a n t e d 24 months a f t e r s p r a y i n g ( 4 0 ) . N o r r i s and M o r r i s (69) found t h a t pea s e e d l i n g r o o t s t r e a t e d w i t h 2,4-D, p i c l o r a m , IAA and NAA c o n t a i n a t l e a s t two p r o t e i n s not found i n t h e c o n t r o l s e e d l i n g s . These p r o t e i n s were found i n r o o t e x t r a c t s made 24 and 48 hours a f t e r t r e a t m e n t but were not e v i d e n t 12 hours a f t e r t r e a t m e n t . The a u t h o r s f e e l t h a t s i n c e t h e same two p r o t e i n s appear a f t e r t r e a t m e n t w i t h d i f f e r e n t c h e m i c a l s t h i s s u g g e s t s t h a t t h e s e p r o t e i n s may be a s s o c i a t e d w i t h t h e p r o l i f e r a t i o n o f l a t e r a l r o o t s , a c o n d i t i o n which was much more p r o f u s e i n t h e t r e a t e d t h a n i n t h e u n t r e a t e d p l a n t s o f comparable age. - 18 -B r o m o x y n i l The mode o f a c t i o n o f b r o m o x y n i l p e r se has not r e c e i v e d a g r e a t d e a l o f a t t e n t i o n . Foy (21) found t h a t i o x y n i l ( 3 , 5 - d i i o d o - 4 - h y d r o x y b e n z o n i t r i l e ) a compound c l o s e l y r e l a t e d t o b r o m o x y n i l , d e c r e a s e s oxygen uptake i n m i t o -c h o n d r i a l p r e p a r a t i o n s when e i t h e r a l p h a - k e t o g l u t r a t e o r , s u c c i n a t e was used as t h e s u b s t r a t e . I o x y n i l i n h i b i t s t h e H i l l r e a c t i o n i n i s o l a t e d c h l o r o p l a s t s and was more a c t i v e t h a n i t s c o u n t e r p a r t , t h e dibromo d e r i v a t i v e b r o m o x y n i l ( 9 7 ) . T r e a t e d l e a v e s l o s t t h e i r green c o l o u r much more r a p i d l y when exposed t o l i g h t . S i m i l a r l y l e a f d i s c s p l a c e d i n aqueous s o l u t i o n s o f i o x y n i l (1,000 ppm) l o s t t h e i r c h l o r o p h y l l i n l i g h t b ut not i n t h e d a r k . I o x y n i l a l s o i n h i b i t s CO,, f i x a t i o n i n b r oad beans a t 1 0 - 6 M and 10" 2M ( 7 3 ) . L a b e l l e d n i t r i l e s appear t o be m e t a b o l i z e d and r e i n c o r p o r a t e d i n t o s t a r c h , g l u t e n and t h e g l u c o s e f r a c t i o n o f t h e mature wheat g r a i n ( 3 6 ) . I n wheat, i o x y n i l and b r o m o x y n i l produce s l i g h t l y c h l o r o t i c h a l o s around areas c o v e r e d by drops o f t h e c h e m i c a l but no c h l o r o s i s was seen on new growth ( 9 ) . Wheat, o a t s and b a r l e y have good t o l e r a n c e t o l e v e l s as h i g h as 1 l b / a c r e o f t h e o c t a n o a t e and b u t y r a t e f o r m u l a t i o n s o f b r o m o x y n i l , p a r t i c u l a r l y when t h e cr o p s a r e i n t h e t i l l e r i n g s t a g e o f growth ( 5 0 ) . When b r o m o x y n i l i s a p p l i e d t o s p r i n g c e r e a l s a f t e r j o i n t i n g , y i e l d s t e n d t o be lo w e r t h a n t h o s e r e s u l t i n g from e a r l i e r a p p l i c a t i o n s ( 4 2 ) . Wheat a t the f i v e l e a f s t a g e i s more s u s c e p t i b l e t o b r o m o x y n i l - 19 -tha n i t i s a t t h e t h r e e l e a f s t a g e . The y i e l d o f T h a t c h e r 2 2 was reduced t o 240 gm/m compared t o 33 0 gm/m when s p r a y e d a t the t h r e e l e a f s t a g e ( 1 0 0 ) . B r o m o x y n i l a t 8 o z / a c r e seems t o de p r e s s t h e y i e l d o f Genesee when t h i s w i n t e r wheat, was s p r a y e d a t 7"-8" ( 5 6 ) . Manitou and S e l k i r k s p rayed w i t h b r o m o x y n i l + MCPA (1:1) a t 8 o z / a c r e showed a r e d u c t i o n i n y i e l d ( 2 8 ) . - 20 -SUMMARY OF LITERATURE REVIEW 2 , 4 - D i c h l o r o p h e n o x y a c e t i c A c i d T h i s compound i s w i d e l y used f o r t h e c o n t r o l o f b r o a d l e a f weeds i n c e r e a l c r o p s , t u r f , p a s t u r e s and non-crop l a n d s . I t i s u s u a l l y used as a p o s t emergence s p r a y . I t i s r e a d i l y absorbed by t h e r o o t s and t h e s h o o t . I t i s f r e e l y t r a n s l o c a t e d i n t h e p l a n t (1,4,39,43,57,67,89) a f f e c t s r e s p i r a t i o n and f o o d r e s e r v e s (5,44,59,60,86,90,93,98) p h o t o s y n t h e s i s (8,62,77) c e l l d i v i s i o n (84) and i n c r e a s e s p r o t e i n and RNA (3,11,45,46,47,79,94,95,100,104). P i c l o r a m P i c l o r a m i s v e r y e f f e c t i v e i n the c o n t r o l o f woody p l a n t s o r p e r e n n i a l b r o a d l e a f h e r b s . I t i s r a p i d l y absorbed and t r a n s l o c a t e d by t h e r o o t s and the shoots o f p l a n t s ( 4 3 , 5 3 ) . I t i s p e r s i s t e n t i n t h e p l a n t t i s s u e as w e l l as i n t h e s o i l ( 4 0 ) . I t has a s i m i l a r p h y s i o l o g i c a l e f f e c t on p l a n t s as 2,4-D (15,56,83,85). B r o m o x y n i l B r o m o x y n i l i s used f o r t h e c o n t r o l o f b r o a d l e a f weed s e e d l i n g s i n c e r e a l g r a i n s . I t i s a c o n t a c t h e r b i c i d e and i s a p p l i e d as a p o s t emergence s p r a y . There i s v e r y l i t t l e movement o f t h i s compound once i t i s absorbed. I t a c t s as a p h o t o s y n t h e t i c and r e s p i r a t o r y i n h i b i t o r ( 73,97). I t may be m e t a b o l i z e d t o b e n z o i c a c i d i n p l a n t s ( 4 1 ) . - 21 -MATERIALS AND METHODS Three s p r i n g wheat v a r i e t i e s , S e l k i r k , M anitou and Pembina, were grown i n t h e f i e l d and the greenhouse. The seed o r i g i n a t e d from t h e Manitoba Research S t a t i o n , CDA, Morden, Ma n i t o b a . Randomized b l o c k d e s i g n s were used i n a l l t h e e x p e r i m e n t a t i o n , except i n the 196 8 f i e l d t r i a l . I n t h e l a t e r t r i a l a s p l i t p l o t d e s i g n was used. F i e l d T r i a l • In 1967 t h e f i e l d e xperiment was c a r r i e d out i n f o u r b l o c k s 10.8 m x 6.0 m each. The i n d i v i d u a l p l o t s i z e was 6 m x 0.9 m w i t h t h r e e rows each 17.5 cm a p a r t . The h e r b i c i d e s p i c l o r a m , 2,4-0 and b r o m o x y n i l were a p p l i e d a t 0.25 o z , 8 oz and 12 o z / a c r e r e s p e c t i v e l y . In 1968 the p l o t s i z e was 2.1 m x 0.9 m w i t h t h r e e rows a t 17.5 cm a p a r t . 2,4-D was a p p l i e d a t 8, 12 and 16 o z / a c r e , p i c l o r a m was a p p l i e d a t 0.25, 0.37 and 0.5 o z / a c r e and b r o m o x y n i l at 12, 18 and 24 o z / a c r e . S p r a y i n g was done a t the 6" s t a g e (4 l e a f ) . The r e q u i r e d amount o f a c t i v e commercial p r o d u c t was s p r a y e d on each p l o t a t t h e r a t e o f 9 5 g a l l o n s o f the w a t e r c a r r i e r p e r a c r e . A 0.6 meter p o l y e t h y l e n e b a r r i e r was used t o p r e v e n t t h e s p r a y d r i f t i n g t o the a d j a c e n t p l o t s . Samples were c o l l e c t e d from t h e c e n t r e row, the two o u t s i d e rows a c t e d as guard rows. The g r a i n was t h r e s h e d and s t o r e d i n t h e c o l d room a t 5°C u n t i l r e q u i r e d . - 22 -Pot Experiment The 3 s p r i n g wheats used i n t h e f i e l d t r i a l were grown o u t s i d e i n p o t s . Ten seeds were sown p e r pot (30 cm x 15 cm d i a m e t e r ) and t h i n n e d t o 4 p l a n t s two weeks l a t e r . F e r t i l i z e r (10:6:6) was a p p l i e d a t the r a t e o f 400 l b / a c r e b e f o r e sowing. H e r b i c i d a l r a t e s s i m i l a r t o t h o s e used i n t h e f i e l d e x p eriment were used f o r the greenhouse s t u d y . The p o t s were brought i n s i d e t h e greenhouse t h r e e weeks b e f o r e h a r v e s t i n g . A l l t h e s p i k e s from each pot were h a r v e s t e d , t h r e s h e d and s t o r e d i n t h e c o l d room u n t i l needed. P e r c e n t N i t r o g e n i n Wheat G r a i n N i t r o g e n was d e t e r m i n e d by the K j e l d a h l method. Whole wheat f l o u r from the f i e l d t r i a l was d r i e d 24 hours a t 80°C i n an oven. The d r i e d samples, r a n g i n g between 0.6 gm - 1.2 gm., were k e p t o v e r n i g h t i n 2 5 ml o f c o n c e n t r a t e d li^SO^^ b e f o r e d i g e s t i n g on the K j e l d a h l u n i t . The d i s t i l l a t e was c o l l e c t e d i n 3% b o r i c a c i d and t i t r a t e d t o t h e end p o i n t w i t h a s t a n d a r d H^SO^. P e r c e n t n i t r o g e n was c o n v e r t e d t o p r o t e i n by m u l t i p l y i n g by 5.7. E x t r a c t i o n o f Albumins and G l o b u l i n s A whole wheat sample was p r e p a r e d u s i n g a W i l e y m i l l (40 mesh). One gram o f the m i l l e d m a t e r i a l was soaked i n 10 ml o f 0.1 M T r i s g l y c i n e b u f f e r pH 8.3 f o r an hour i n t h e c o l d . The sample b u f f e r m i x t u r e was homogenized i n a m o r t a r and p e s t l e w i t h a c i d washed sand. The r e s u l t i n g - 23 -homogenate was centrifuged at 25,000xg for 30 minutes at 2°C. The supernatant containing albumin and globulin was retained and stored i n the cold at 2°C for protein estimation and electrophoresis. Extraction of Glutens The whole wheat samples were prepared i n a manner si m i l a r to that used i n the extraction of albumins and globulins. One gram of the material was extracted i n 10 ml of 0.05 N acetic acid for twelve hours. The preparation was then homogenized, centrifuged and the supernatant gluten portion stored as for the albumins and globulins. The extracted gluten material was used within 12 hours from the time of centrifugation. Estimation of Protein Proteins—albumins, globulins and glutens—extracted by the two d i f f e r e n t buffers were estimated by the F o l i n phenol method of Lowry et aJL. 1951 (63). The readings were taken on an recording spectrophotometer (Beckman Du) 30 minutes a f t e r the addition of the F o l i n reagent. The micro-grams of protein per ml of the supernatant were calculated from the standard curve made from 3X c r y s t a l l i z e d bovine serum albumin. Electrophoresis of Soluble Proteins Extracted with 0-.1M  Tr i s - g l y c i n e Buffer pH 8.3 (Albumins and Globulins) Disc electrophoresis on a small column of polyacrylamide g e l , a method developed by Ornstein and Davis, - 24 -was used for the separation of wheat protein (71). The Tr i s - g l y c i n e buffer extracts, mainly albumins and globulins, were subjected to electrophoresis i n 7%% acrylamide gel at pH 8.3 (2,81). Preparation of Gel and Electrophoresis  Stock Solutions The upper and lower gels were prepared from the following stock solutions: A 1 N HC1 24 .0 ml T r i s (Eastman) 15 .85 gm Temed (Eastman) 0 .32 ml Water To 100 .0 ml B 1 N HC1 48 .0 ml T r i s 5 .98 gm Temed 0 .32 ml Water To 100 .0 ml C Acrylamide (Eastman) 30 .0 gm Bis 0 .8 gm Water 100 .0 ml D Acrylamide 10 .5 gm Bis 2 .5 gm Water To 100 .0 ml E Riboflavin 0 .004 gm Water To 100 .0 ml - 25 -Sucrose Water Ammonium P e r s u l f a t e Water To 40.0 gm 100.0 ml 0.14 gm ( P r e p a r e d w e e k l y ) 100.0 ml St o c k s o l u t i o n s were s t o r e d i n brown b o t t l e s i n t h e r e f r i g e r a t o r . Working S o l u t i o n s The w o r k i n g s o l u t i o n s were p r e p a r e d j u s t p r i o r t o use as f o l l o w s : 1. Lower G e l 1 p a r t o f s o l u t i o n A 2 p a r t s o f s o l u t i o n C 1 p a r t o f B e i o n i z e d w a t e r 2. Upper G e l 1 p a r t o f s o l u t i o n B 2 p a r t s o f s o l u t i o n D 2 p a r t s o f s o l u t i o n E 3 p a r t s o f s o l u t i o n F T h i s was mixed 1:1 w i t h s o l u t i o n G and p o l y m e r i z e d f o r 15-2 0 minutes P o l y m e r i z e d f o r 20-25 minutes w i t h f l u o r e s c e n t l i g h t A l l t h e s t o c k s o l u t i o n s were brought t o room te m p e r a t u r e b e f o r e making the w o r k i n g s o l u t i o n s . The p r e p a r e d g e l s were used w i t h i n one hour from t h e time o f m i x i n g the l o w e r g e l . P o l y m e r i z a t i o n o f t h e G e l Twelve open-ended g l a s s t u b e s 7 cm x 0.5 cm were used f o r each e l e c t r o p h o r e s i s e x p e r i m e n t . The l o w e r g e l s o l u t i o n was p i p e t t e d i n t o each tube ( b e f o r e p o l y m e r i z a t i o n ) and t h e n p o l y m e r i z e d f o r 15-2 0 m i n u t e s . S i m i l a r l y t h e upper g e l was p i p e t t e d and p o l y m e r i z e d on t o p o f t h e l o w e r g e l . Care was t a k e n t o get a sharp boundary between the upper and l o w e r g e l s . Tubes c o n t a i n i n g the p o l y m e r i z e d g e l s were a t t a c h e d t o t h e r u b b e r grommets o f t h e upper e l e c t r o d e v e s s e l as shown i n F i g . 1. The upper and l o w e r e l e c t r o d e v e s s e l s were each f i l l e d w i t h 250 ml o f p r e - c h i l l e d T r i s - g l y c i n e b u f f e r (0.1M pH 8.3). Three hundred micrograms o f p r o t e i n , c a l c u l a t e d from Lowry's F o l i n t e s t , were l a y e r e d on t o p o f t h e upper g e l by u s i n g a l o n g - t i p p e d p i p e t . Two t o t h r e e drops o f 1% Bromophenol b l u e ( t r a c k i n g dye) were added t o t h e b u f f e r s o l u t i o n i n t h e upper v e s s e l and the p o s i t i v e t e r m i n a l o f t h e d i r e c t c u r r e n t power s u p p l y ( B u c h l e r i n s t r u m e n t s ) was connected t o t h e e l e c t r o d e o f the l o w e r b u f f e r c o n t a i n e r . The n e g a t i v e t e r m i n a l o f t h e power s u p p l y was connected t o t h e e l e c t r o d e i n t h e b u f f e r c o n t a i n e r . The e l e c t r o p h o r e s i s was t e r m i n a t e d when the t r a c k i n g dye was about 1 cm from th e bottom end o f t h e g e l w h i c h t o o k about 65-70 m i n u t e s . E l e c t r o p h o r e s i s o f P r o t e i n s E x t r a c t e d w i t h 0.05 N  A c e t i c A c i d ( G l u t e n s ) The 0.05 N a c e t i c a c i d e x t r a c t s , m a i n l y g l u t e n s , were s u b j e c t e d t o e l e c t r o p h o r e s i s i n 1\% a c r y l a m i d e g e l s a t The d i s c e l e c t r o p h o r e s i s - The upper b u f f e r c o n t a i n e r with the g l a s s tubes attached - The upper and lower b u f f e r c o n t a i n e r s - 2'8 -a t pH 5.0 as d e s c r i b e d by R e i s f i e l d e t a l . (81) w i t h some m o d i f i c a t i o n s . P r e p a r a t i o n o f G e l s and E l e c t r o p h o r e s i s The l o w e r and upper g e l s were p r e p a r e d from t h e f o l l o w i n g s t o c k s o l u t i o n s : 1 N P o t a s s i u m H y d r o x i d e 48 .0 ml A c e t i c A c i d ( G l a c i a l ) 17 .2 ml Temed 4 .0 ml Water To 100 .0 ml 1 N P o t a s s i u m H y d r o x i d e 48 .0 ml A c e t i c A c i d ( G l a c i a l ) 2 . 87 ml Temed 0 .46 ml Water To 100 .0 ml S o l u t i o n s C, D, E, F and G were s i m i l a r t o t h e s t o c k s o l u t i o n s made f o r t h e e l e c t r o p h o r e s i s o f albumins and g l o b u l i n s . S t a i n i n g and D e s t a i n i n g G e l s ( A l b u m i n s , G l o b u l i n s and G l u t e n s ) At t h e end o f e l e c t r o p h o r e s i s t h e g e l columns were removed from t h e t u b e s , by g e n t l y "rimming" them a t t h e l o w e r end w i t h a hypodermic n e e d l e t h r o u g h w h i c h water was f l o w i n g . The g e l s were put i n 1% amido b l a c k w/v i n 10% a c e t i c a c i d • v/v f o r a t l e a s t an hour. The s t a i n e d g e l s were k e p t o v e r -n i g h t i n 400 ml o f ^ 0 t o remove t h e exce s s s t a i n . When t h e p a r t o f t h e g e l beyond the f r o n t o f t h e t r a c k i n g dye was c l e a r , t h e g e l s were put i n t e s t tubes and - 29 -s t o r e d i n 10% a c e t i c a c i d f o r s c a n n i n g and photography. R e c o r d i n g and R e s u l t s The g e l s were scanned w i t h a d e n s i t o m e t e r ( J o y c e -L o e l chromoscan) u s i n g 1 mm and 0.37 mm s l i t w i d t h s w i t h a 1:3 gear r a t i o o f g e l t o c h a r t . D u r i n g e l e c t r o p h o r e s i s i t was d i f f i c u l t t o a r r a n g e t h a t each sample r a n e x a c t l y t h e same l e n g t h i n t h e l o w e r g e l , hence t h e t r a c k i n g dye f r o n t was t a k e n as 100 and t h e p r o t e i n bands were r e l a t e d t o t h i s f r o n t . P r o t e i n bands w i t h s i m i l a r R^'s were d i r e c t l y comparable t o each o t h e r . - 30 -RESULTS Y i e l d I n t h e 1967 f i e l d e x p eriment i t was found t h a t each v a r i e t y r e a c t e d d i f f e r e n t l y t o t h e t h r e e h e r b i c i d e s as seen i n T a b l e 1. 2,4-D a t t h e r a t e o f 8 o z / a c r e d e c r e a s e d t h e y i e l d o f a l l 3 v a r i e t i e s , but Pembina was t h e o n l y v a r i e t y whose y i e l d was s i g n i f i c a n t l y r e d u c e d . P i c l o r a m t o o d e c r e a s e d t h e y i e l d s o f Pembina a t 0.25 o z / a c r e w h i c h was s i g n i f i c a n t a t t h e 5% l e v e l . B r o m o x y n i l a t 12 o z / a c r e i n c r e a s e d t h e y i e l d o f M a n i t o u by 4 0.2 gm o v e r t h a t o f t h e c o n t r o l . I n the 196 8 f i e l d e x p e r i m e n t , where h i g h e r c o n c e n t r a t i o n s o f t h e t h r e e h e r b i c i d e s were used, b r o m o x y n i l was t h e o n l y h e r b i c i d e t h a t produced any s i g n i f i c a n t y i e l d r e d u c t i o n s ( T a b l e 2 ) . M a n i t o u and Pembina were more s u s c e p t i b l e t h a n S e l k i r k t o b r o m o x y n i l r e g a r d l e s s o f t h e c o n c e n t r a t i o n o f t h e h e r b i c i d e used. I n t h e v a r i e t y M a n i t o u the y i e l d was 10 3.7, 45.6 and 11.6 gm/plot f o r t h e t r e a t m e n t s o f 0, 12 and 24 oz b r o m o x y n i l / a c r e r e s p e c t i v e l y . The y i e l d s o f Pembina i n gm/plot were 98.8 a t 0 oz b r o m o x y n i l / a c r e and 16.3 gm f o r 24 oz b r o m o x y n i l / a c r e . 2,4-D and p i c l o r a m had no s i g n i f i c a n t e f f e c t i n i n c r e a s i n g o r d e c r e a s i n g t h e y i e l d on any o f t h e v a r i e t i e s even a t 16 and 0.5 o:z/acre o f 2,4-D and p i c l o r a m r e s p e c t i v e l y . I n S e l k i r k t h e r e was an i n i t i a l i n c r e a s e i n t h e y i e l d w i t h l o w e r r a t e s o f 2,4-D and p i c l o r a m . However, a t t h e h i g h e r - 31 -Ta b l e 1 THE EFFECT OF HERBICIDES ON THE Y I E L D + OF WHEAT 1967 H e r b i c i d e C o n t r o l 2 ,4-D B r o m o x y n i l P i c l o r a m Rates i n o z / a c r e 8 12 0 2 5 Wheat V a r i e t i e s S e l k i r k M a n i t o u Pembina 304.6 AB 270.6 BC 302.5 AB 269.6 BC 284.4 BC 266.6 CD 324.6 A 270.1 BC 299.6 ABC 248.1 D 270.1 BC 226.8 D Ta b l e 2 THE EFFECT OF HERBICIDES ON THE Y I E L D + OF WHEAT 19 6 8 H e r b i c i d e 2,4-D B r o m o x y n i l P i c l o r a m Rates i n Wheat V a r i e t i e s o z / a c r e S e l k i r k M a n i t o u Pembina 0 # 99.7 f f 103 .7 AB 98.8 A 8 129.0 78.9 BCD 90.6 AB 12 122 .9 78.4 BCD 116.1 A 16 86.0 103 .7 AB 85 .5 AB 0 99.7 103 .7 AB 98 . 8 A 12 90.8 45.6 CDE 50.0 BC 18 87 .4 36.1 E 35.0 C 24 71.4 11.6 E 16.3 C 0 99.7 103.7 AB 98.8 A 0.25 108.0 109.6 AB 83.8 AB 0.37 111.3 82 .7 ABCD 93.3 AB 0.50 91.9 91.8 ABC 104.4 A N.B. Each v a l u e i s t h e average o f 4 r e p l i c a t i o n s . V a l u e s f o l l o w e d by the same l e t t e r do not d i f f e r s i g n i f i c a n t l y a t t h e 5% l e v e l o f p r o b a b i l i t y . No s i g n i f i c a n t d i f f e r e n c e s + Y i e l d i n gm/plot - 32 -r a t e s t h e y i e l d d e c r e a s e d below t h a t o f the c o n t r o l . W i t h i n c r e a s i n g c o n c e n t r a t i o n o f p i c l o r a m t h e r e was a t r e n d toward d e c r e a s i n g y i e l d i n the v a r i e t y M a n i t o u , whereas w i t h Pembina the y i e l d p e r p l o t i n c r e a s e d from 83.8 t o 101.8 w i t h 0.25 and 0.5 oz p i c l o r a m / a c r e r e s p e c t i v e l y . 2,4-D had no c o n s i s t e n t e f f e c t on t h e v a r i e t y Pembina. P e r c e n t a g e P r o t e i n I n t h e 1967 f i e l d e xperiment t h e r e was no s i g n i f i c a n t i n c r e a s e o r d e c r e a s e i n the p e r c e n t a g e p r o t e i n i n t h e 3 v a r i e t i e s t r e a t e d w i t h p i c l o r a m , 2,4-D and b r o m o x y n i l a t 0. 25, 8 and 12 o z / a c r e r e s p e c t i v e l y ( T a b l e 3 ) . 2,4-D and b r o m o x y n i l tended t o i n c r e a s e t h e p e r c e n t a g e p r o t e i n compared t o the c o n t r o l , w h i l e p i c l o r a m on t h e o t h e r hand reduced the p e r c e n t a g e p r o t e i n i n a l l t h r e e v a r i e t i e s . B r o m o x y n i l was t h e o n l y h e r b i c i d e t h a t i n c r e a s e d t h e p e r c e n t a g e p r o t e i n s i g n i f i c a n t l y o v e r t h a t o f t h e c o n t r o l 1. e. i n M a n i t o u and Pembina ( T a b l e 4 ) . A d e c r e a s i n g t r e n d i n M a n itou and an i n c r e a s i n g t r e n d i n Pembina i n t h e p e r c e n t a g e p r o t e i n was n o t i c e d as t h e r a t e s o f p i c l o r a m i n c r e a s e d from 0 t o 0.5 o z / a c r e . Both t h e s e v a r i e t i e s d i d not i n d i c a t e a d e f i n i t e p r o t e i n p a t t e r n f o r t h e 2,4-D t r e a t m e n t s . I n a d d i t i o n t h e r e was an i n c r e a s i n g t r e n d w i t h 2,4-D and b r o m o x y n i l i n S e l k i r k but no s i m i l a r t r e n d was o b s e r v e d w i t h p i c l o r a m t r e a t m e n t s . P r o t e i n Y i e l d P e r P l o t None o f the t r e a t m e n t s i n t h e 1967 f i e l d t r i a l - 33 -Tabl e 3 THE EFFECT OF HERBICIDES ON PERCENT PROTEIN + OF WHEAT 196 7 Rate i n Wheat V a r i e t i e s H e r b i c i d e o z / a c r e S e l k i r k M a nitou Pembina C o n t r o l 11.0 # 12.4 13.3 2,4-D 8 11.9 13.0 14.0 Br o m o x y n i l 12 11.6 11.8 13.7 P i c l o r a m 0.25 10.8 12.1 12.9 Ta b l e 4 XIDES 01 OF WHEAT 19 6 8 THE EFFECT OF HERBICI ON PERCENT PR0TEIN + „ + n • Wheat V a r i e t i e s Rate xn H e r b i c i d e o z / a c r e S e l k i r k M a nitou Pembina 2 ,4-D 0 12 .5 EFG 13 .0 DEF 11 . 7 EFG 8 12 .2 EFG 12 .0 EFG 13 .6 DEF 12 13 .5 DEF 13 .4 DEF 13 .6 DEF 16 13 .4 DEF 12 .9 DEF 12 .4 EFG B r o m o x y n i l 0 12 .5 EFG 13 .0 DEF 11 .7 EFG 12 12 .9 DEF 17 . 3 AB 15 .6 BC 18 14 .8 CD 16 .7 AB 17 .1 AB 24 14 .3 CDE 18 .7 A 17 .5 A P i c l o r a m 0 12 .5 EFG 13 .0 DEF 11 .7 EFG 0 . 25 11 .9 EFG 13 .7 CDEF 12 .4 EFG 0 . 37 11 . 8 EFG 12 .0 EFG 12 .9 DEF 0. 50 13 .0 DEF 12 .3 EFG 13 .0 DEF N.B. Each v a l u e i s t h e average o f 4 r e p l i c a t i o n s . V a l u e s f o l l o w e d by t h e same l e t t e r do not d i f f e r s i g n i f i c a n t l y a t t he 5% l e v e l o f p r o b a b i l i t y . #No s i g n i f i c a n t d i f f e r e n c e s + P e r c e n t p r o t e i n = (% N i t r o g e n x 5.4). - 34 -s i g n i f i c a n t l y d e c r e a s e d o r i n c r e a s e d the y i e l d o f p r o t e i n i n gm/plot (% p r o t e i n x g r a i n y i e l d i n gm/plot) ( T a b l e 5 ) . I n the 1968 e x p e r i m e n t , when the 3 r a t e s o f each h e r b i c i d e were used, b r o m o x y n i l was t h e o n l y h e r b i c i d e t h a t s i g n i f i c a n t l y r educed th e p r o t e i n y i e l d / p l o t i n M a n i t o u and Pembina ( T a b l e 4 ) . The p r o t e i n y i e l d o f M a nitou dropped from 13.4 gm t o 5.2 and 2.2 gm/plot f o r 0, 18 and 2 4 oz b r o m o x y n i l / a c r e r e s p e c t i v e l y . Xn Pembina i t dropped from 11.8 t o 6.0 and 2.8 gm/plot f o r 0, 18 and 24 o z / a c r e r e s p e c t i v e l y . There was an i n i t i a l i n c r e a s e i n p r o t e i n y i e l d / p l o t i n S e l k i r k w i t h low r a t e s o f 2,4-D and p i c l o r a m , but a t the h i g h e s t r a t e t h e p r o t e i n y i e l d d e c r e a s e d . There was no s i g n i f i c a n t i n c r e a s e o r d e c r e a s e i n the p r o t e i n y i e l d / p l o t i n M a nitou and Pembina w i t h any r a t e o f 2,4-D. P i c l o r a m on the o t h e r hand produced a d e c r e a s i n g t r e n d i n M a n i t o u and an i n c r e a s i n g t r e n d i n Pembina w i t h i n c r e a s i n g a p p l i c a t i o n r a t e s o f the c h e m i c a l . S o l u b l e P r o t e i n Measured by F o l i n T e s t There was no t r e n d o r r e l a t i o n s h i p between the amounts o f s o l u b l e p r o t e i n e x t r a c t e d a t pH 8.3 o r pH 3.5 as measured by Lowry's F o l i n P h e n o l T e s t nor i n e i t h e r t h e p e r c e n t p r o t e i n i n t h e wheat k e r n e l o r t h e t o t a l p r o t e i n y i e l d p e r p l o t . On average more s o l u b l e p r o t e i n was e x t r a c t e d a t pH 8.3 (1470 ±50 micrograms/ml) t h a n a t pH 3.5 (650+50 micrograms/ml) (Appendix T a b l e 1 ) . - 35 -Tab l e 5 THE EFFECT OF HERBICIDES ON PROTEIN Y I E L D + 19 67 H e r b i c i d e C o n t r o l 2,4-D B r o m o x y n i l P i c l o r a m Rates i n o z / a c r e 8 12 0.25 Wheat V a r i e t i e s S e l k i r k 35.5 32.1 35.2 29.1 Ma n i t o u 35 .4 34.8 38.4 33.8 Pembina 39.7 34.5 37.0 29.2 Ta b l e 6 THE EFFECT OF HERBICIDES ON PROTEIN Y I E L D + 1968 H e r b i c i d e Rates i n o z / a c r e Wheat V a r i e t i e s S e l k i r k M a n i t o u Pembina 2 ,4-D 0 12 .6 ABCD 13 .4 ABCD 11. 8 ABCDE 8 15 . 3 ABC 9 .5 CDEF 11. 6 ABCDE 12 16 .5 A 10 .6 ABCDEF 15. 5 ABC 16 11 .4 ABCDE 13 .6 ABC 10 . 8 ABCDEF B r o m o x y n i l 0 12 .6 ABCD 13 .4 ABCD 11. 8 ABCDE 12 11 .7 ABCDE 7 7 .7 DEFG 8. 5 DEF 18 13 .2 ABCD 5 .2 GH 6. 0 EFGH 24 10 .1 ABCDEF 2 .2 H 2 . 8 GH P i c l o r a m 0 12 .6 ABCD 13 .4 ABCD 11. 8 ABCDE 0. 25 12 .8 ABCD 14 . 8 ABC 10. 4 ABCDE 0 . 37 13 .1 ABCD 10 .7 ABCDEF 11. 8 ABCDE 0 . 50 12 . 0 ABCDE 11 .1 ABCDEF 13. 6 ABCD N.B. Each v a l u e average o f 4 r e p l i c a t i o n s . V a l u e s f o l l o w e d by t h e same l e t t e r do n o t d i f f e r s i g n i f i c a n t l y a t 5% l e v e l o f p r o b a b i l i t y . + P r o t e i n y i e l d e x p r e s s e d i n gm/plot = ( p e r c e n t p r o t e i n x g r a i n y i e l d / p l o t ) - 36 -Zone E l e c t r o p h o r e s i s o f t h e S o l u b l e P r o t e i n s E x t r a c t e d  by 0.1 M T r i s - g l y c i n e B u f f e r pH 8.3 ( A l b u m i n s - G l o b u l i n s ) The p r o t e i n s e x t r a c t e d by 0.1 M T r i s - g l y c i n e b u f f e r were m a i n l y albumins and g l o b u l i n s ( 2 ) . These were f u r t h e r s e p a r a t e d on lh% p o l y a c r y l a m i d e g e l a t pH 8.3. The r e s u l t i n g bands were q u a l i t a t i v e l y s i m i l a r and c h a r a c t e r i s t i c o f each v a r i e t y ( F i g . 2 ) . Only q u a n t i t a t i v e d i f f e r e n c e s e x i s t e d between the t r e a t e d and t h e u n t r e a t e d g r a i n s . However, the g e l !-/pattern o b t a i n e d was r e p r o d u c i b l e and any o b s e r v e d d i f f e r e n c e s between the t r e a t e d g r a i n w i t h i n a v a r i e t y were m e a n i n g f u l . D e n s i t o m e t r i c t r a c e s o f t h e e l e c t r o p h o r e t i c s e p a r a t i o n o f t h e s o l u b l e p r o t e i n (whole g r a i n ) i n 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3 s t a i n e d w i t h 7% amido-black a r e shown i n F i g s . 3 , 4 and 5. A s c a l e (movement o f f r o n t = 100) i s added t o the d e n s i t o m e t r i c t r a c e s , so t h a t i n d i v i d u a l peaks (bands o f p r o t e i n / s ) can be r e f e r r e d t o by numbers, which r e p r e s e n t t h e i r movement r e l a t i v e t o t h e f r o n t . The h e i g h t o f the peak i s used as a measure o f t h e amount o f t h e p r o t e i n i n each band, assuming t h a t t h e r e i s a l i n e a r r e l a t i o n s h i p between the bound dye and t h e amount o f p r o t e i n p r e s e n t i n each band. Comparisons can t h e n be made w i t h i n each p a t t e r n . S e l k i r k S e l k i r k v a r i e t y was t h e l e a s t a f f e c t e d by any o f the h e r b i c i d e s , as seen from T a b l e 2, 3 and 4. I t showed the B Figure 2. Densitometric t r a c e s of e l e c t r o p h o r e t i c s e p a r a t i o n s of the s o l u b l e p r o t e i n s A. A l b u m i n s - g l o b u l i n s - - e x t r a c t e d with t r i s - g l y c i n e b u f f e r , 0.1M, pH 8.3 B. G l u t e n s — e x t r a c t e d with 0.05 N a c e t i c a c i t pH 3.5. - 38 -Figure 3. Densitometric t r a c e s of the e l e c t r o -p h o r e t i c separations of the s o l u b l e p r o t e i n s (albumins-globulins) of whole wheat g r a i n (var. S e l k i r k ) e x t r a c t e d with 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n 7*5% acrylamide gels using t r i s - g l y c i n e b u f f e r , 0.1 M, pH 8.3. - 39 -fiat e 3 lit u \ V, J I R a t e 2 244-D Rate 1 > i \ MANITOU ! 1 Rate 2 oromoxym Rate 1 10.0 •.  0 50 IOC J i — i — i « i i . . . . i ConH Figure 4. Densitometric t r a c e s of the e l e c t r o -p h o r e t i c separations of the s o l u b l e p r o t e i n s (albumins-globulins) of whole wheat g r a i n . ( v a r . Manitou) e x t r a c t e d with 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n 7?s% acrylamide gels using t r i s -g l y c i n e b u f f e r , 0.1 M, pH 8.3. 0 T f, -50 - 40 2,4-D R u t e 1 PEMBINA j 1 I \ \ f \ 1 \ \ B r o m o x y n i l Rare 1 0 l_ V W \ \ J V \ s 1 1 \ / 1 1 • • L / \ s V V % 1 Ti ra fl Piclora r n I P rt t s 1 i" V v u* 50 T O O 0 t— C o n t r o l Figure 5. Densitometric t r a c e s of the e l e c t r o -p h o r e t i c separations of the s o l u b l e p r o t e i n s (albumins-globulins) of whole wheat g r a i n (var. Pembina) ex t r a c t e d with 0.1 M t r i s - g l y c i n e b u f f e r pH 8.3. E l e c t r o p h o r e s i s i n 7*s% acrylamide gels using t r i s -g l y c i n e b u f f e r , 0.1 M, pH 8.3. - 41 -s m a l l e s t q u a n t i t a t i v e changes i n the albumin and g l o b u l i n f r a c t i o n ( F i g . 3 ) . 2,4-D a t r a t e s 1 and 2 and p i c l o r a m a t r a t e s 1, 2 and 3 tends t o i n c r e a s e t h e peak 30 and d e c r e a s e the peak R^ 21. At t h e h i g h e s t r a t e o f 2,4-D t h e r e was no change. B r o m o x y n i l , which tends t o i n c r e a s e t h e p e r c e n t p r o t e i n ( T a b l e 4) a p p a r e n t l y had no a f f e c t on the p r o t e i n m o i e t i e s . M a n i t o u B r o m o x y n i l , w h i c h had i n c r e a s e d t h e p e r c e n t p r o t e i n i n M a n i t o u ( T a b l e 4 ) , seems t o show a c h a r a c t e r i s t i c i n c r e a s e i n t h e p r o t e i n peak R^ 78 ( F i g . 4) w i t h a l l t h e a p p l i c a t i o n r a t e s o f b r o m o x y n i l . 2,4-D a t any a p p l i c a t i o n r a t e and p i c l o r a m a t a p p l i c a t i o n r a t e s 1 and 2 show no e f f e c t on t h e q u a n t i t y o f any f r a c t i o n o f a l b u m i n and g l o b u l i n s e p a r a t e d . P i c l o r a m a t the h i g h e s t r a t e o f a p p l i c a t i o n (\ o z / a c r e ) d e p r e s s e s t h e p r o t e i n c h a r a c t e r i z e d by t h e R f 20. Pembina No q u a n t i t a t i v e change was seen i n t h e albumin g l o b u l i n p r o t e i n s s e p a r a t e d as a r e s u l t o f any o f t h e t r e a t m e n t s o f 2,4-D and a p p l i c a t i o n r a t e s 1 and 2 o f p i c l o r a m . P i c l o r a m a t an a p p l i c a t i o n r a t e 3 (0.5 o z / a c r e ) causes a d r a s t i c d e c r e a s e i n t h e p r o t e i n a t R^ 30, which i s a somewhat s i m i l a r r e s p o n s e t o t h a t seen i n v a r i e t y M a n i t o u . B r o m o x y n i l - 42 -r e s u l t e d i n a c h a r a c t e r i s t i c i n c r e a s e i n t h e p r o t e i n a t 48 and 76. T h i s i n c r e a s e o f p r o t e i n d i d not seem t o be a s s o c i a t e d w i t h a r e d u c t i o n o f any o t h e r p r o t e i n . Zone E l e c t r o p h o r e s i s o f S o l u b l e P r o t e i n s E x t r a c t e d by  0.05 N A c e t i c A c i d pH 3.5 ( G l u t e n s ) The s o l u b l e p r o t e i n s e x t r a c t e d by 0.0 5 N a c e t i c a c i d pH 3.5 m a i n l y c o n s i s t i n g o f g l u t e n s (2) and s e p a r a t e d on lh% p o l y a c r y l a m i d e g e l a t pH 5.0 were q u a l i t a t i v e l y almost s i m i l a r ( F i g . 2 ) . D e n s i t o m e t r i c t r a c e s o f t h e s t a i n e d g e l s f o l l o w i n g t h e e l e e t r o p h o r e t i c s e p a r a t i o n o f the g l u t e n s ( F i g s . 6, 7 and 8) d i d show some q u a n t i t a t i v e d i f f e r e n c e s . A s c a l e s i m i l a r t o t h a t mentioned f o r t h e albumins and g l o b u l i n s was used. Here t o o , t h e h e i g h t o f each peak was used as a q u a n t i t a t i v e measure o f p r o t e i n i n each band. S e l k i r k The 0.05 N a c e t i c a c i d s o l u b l e p r o t e i n from S e l k i r k g r a i n showed a s l i g h t q u a n t i t a t i v e change as a r e s u l t o f t h e use o f 2,4-D and b r o m o x y n i l . 2,4-D a t r a t e s 1 and 2 seems t o i n c r e a s e t h e p r o t e i n l o c a t e d a t R^ . 63. On t h e o t h e r hand a t the h i g h e s t l e v e l o f a p p l i c a t i o n t h e r e i s a d e c r e a s e i n p r o t e i n l o c a t e d a t R^ 2 0 and 28. B r o m o x y n i l a t a p p l i c a t i o n r a t e 1 on t h e o t h e r hand i n c r e a s e d band R^ 6 3 and d e c r e a s e d band R^ 20 and 28. However, the a p p l i c a t i o n r a t e s 2 and 3 had no e f f e c t . P i c l o r a m d i d not seem t o a f f e c t t h e c o n c e n t r a t i o n o f t h e s e p a r a t e d p r o t e i n bands. - 43 -w \ J {?!' ' / ' 1 \ \ J. .-, f \ \ j 1 I / \ V 7 > Rate \ f 1 • j • LL .••••I j—i—I Jjl _ 1 |. _ 1 \ 1 i-i;-"' . A \ H j J ; \ / / i.. l-D SELKIRK \ / 7 i y / L \ k V J k Figure 6 . Densitometric t r a c e s o f the e l e c t r o -p h o r e t i c separations of the s o l u b l e p r o t e i n s . ( g l u t e n s ) of whole wheat g r a i n ( v a r . , S e l k i r k ) e x t r a c t e d with 0.05 N a c e t i c a c i d pH 3.5. E l e c t r o -phoresis i n 7ij% acrylamide gels using a 8 - a l a n i n e - a c e t i c a c i d b u f f e r pH 5.0. O 50 TOO I V J I / \ J mi. M A N I T O U P Bromo xynil Rate 1 Figure 7. Densitometric t r a c e s of the e l e c t r o -p h o r e t i c separations of the s o l u b l e p r o t e i n s (glutens) of whole wheat g r a i n (var. Manitou) e x t r a c t e d with 0,05 N a c e t i c a c i d pH 3.5. E l e c t r o -p h o r e s i s i n 7l*% acrylamide gels using a 0 - a l a n i n e - a c e t i c a c i d b u f f e r pH 5.0. SifaJ. •; XTi if ..I:: - 45 -Rate 3 B r o m o x y n i l Picloram Rate 1 EMBiNA 0 50 100 0 If 1 . . • • i . • • . I L_ A • • 10( Figure 8, Densitometric traces of the electro-phoretic -separations of the soluble proteins (glutens) of whole wheat grain (var. Pembina) extracted with 0.05 N acetic acid pH 3.5. Electro-phoresis i n 7^% acrylamide gels using a B-alanine-acetic acid buffer pH 5.0. 100 - 46 -Ma n i t o u M a n i t o u showed n o t i c e a b l e q u a n t i t a t i v e changes i n t h e g l u t e n f r a c t i o n w i t h t h e t r e a t m e n t s . 2,4-D i n c r e a s e d t h e p r o t e i n band l o c a t e d a t R^ 5 8 w i t h a c o r r e s p o n d i n g d e c r e a s e i n bands l o c a t e d a t t h e R^ . 15 and 21. P i c l o r a m a t a p p l i c a t i o n r a t e s 1, 2 and 3 seem t o have no n o t i c e a b l e e f f e c t e x c e p t t h a t the a p p l i c a t i o n r a t e 2 showed r e s u l t s s i m i l a r t o t h e 2,4-D t r e a t m e n t . B r o m o x y n i l , which s t i m u l a t e d an i n c r e a s e i n p e r c e n t p r o t e i n i n M a n i t o u ( T a b l e 4) p r e s e n t e d a c h a r a c t e r i s t i c i n c r e a s e i n t h e p r o t e i n bands l o c a t e d a t R^ 5 8 and 70 w i t h d e c r e a s e s i n p r o t e i n bands l o c a t e d a t R^ . 15, 21 and 90. Pembina The 0.05 N a c e t i c a c i d e x t r a c t a b l e g l u t e n o f Pembina d i d not show any d i s t i n c t q u a n t i t a t i v e change such as t h a t o b s e r v e d w i t h M a n i t o u . 2,4-D had no e f f e c t on p r o t e i n bands. B r o m o x y n i l a t r a t e s 1, 2 and 3 showed an i n c r e a s e i n t h e p r o t e i n band l o c a t e d a t R^ 6 8 as was t h e case w i t h M a n i t o u . I n c r e a s i n g r a t e s o f a p p l i c a t i o n o f p i c l o r a m on t h e o t h e r hand d e p r e s s e d t h e p r o t e i n bands l o c a t e d a t R-. 15 and 20. - 47 -DISCUSSION Growth reactions are generally stimulated by low concentrations of auxin or auxin type growth regulators and i n h i b i t e d by higher concentrations. The i n h i b i t i o n e f f e c t s may be extensions of the same auxin action which brought about the i n i t i a l stimulation, or a l t e r n a t i v e l y they may be due to toxic concentration e f f e c t s , including the disruption of the normal c e l l permeability and a leaching of materials from the c e l l s (57). The differences i n a c t i v i t y of auxins on a molar basis can be related to differences i n t h e i r physical adsorptive properties (57). This adsorptive concept assumes that there are separate adsorptive s i t e s f o r the promoting and i n h i b i t i n g actions of the growth substances. Freed et a l . (23) described several 2,4-D effects which suggested t h i s type of adsorptive action. The stimulatory e f f e c t of 2,4-D and picloram on the yi e l d s of Selkirk; 2,4-D on Pembina; and picloram on Manitou, could be explained i n the l i g h t of t h i s low concentration stimulation and high concentration i n h i b i t i o n of growth ( y i e l d ) . The d i s s i m i l a r behaviour of Manitou and Pembina to 2,4-D and picloram i s d i f f i c u l t to understand, but the response was attributed to the genetic differences. Bromoxynil, a contact herbicide, decreased the y i e l d i n a l l three v a r i e t i e s . The decrease was d i r e c t l y r elated to the amount of the herbicide used. - 48 -There was a d e f i n i t e i n v e r s e r e l a t i o n s h i p between the percent p r o t e i n and the y i e l d . T h i s i s to be expected and agrees with e a r l i e r f i n d i n g s (16,30,52,104). However, Manitou and Pembina d i d not e n t i r e l y f o l l o w t h i s g e n e r a l i z a t i o n . The p i c l o r a m treatment e s p e c i a l l y was at v a r i a n c e . These two v a r i e t i e s have a 50 percent common g e n e t i c i n h e r i t a n c e which c o u l d c o n s t i t u t e a reason f o r the abnormal p r o t e i n - y i e l d r e l a t i o n they show f o l l o w i n g p i c l o r a m treatments. The t o t a l p r o t e i n per p l o t appeared to be more a f f e c t e d by the bromoxynil treatment than by o t h e r h e r b i c i d e s t e s t e d . The e f f e c t of bromoxynil i n i n h i b i t i n g growth ( y i e l d ) c o u l d account f o r t h i s low t o t a l p r o t e i n . Auxins at lower c o n c e n t r a t i o n s i n c r e a s e the n u c l e i c a c i d metabolism i n a t r e a t e d p l a n t (49). Likewise h e r b i c i d a l c o n c e n t r a t i o n s of 2,4-D and p i c l o r a m a l s o i n c r e a s e the RNA content i n the t r e a t e d p l a n t s (3,11,100). Lower c o n c e n t r a t i o n s of these chemicals seem to e i t h e r maintain o r decrease the RNA i n the t r e a t e d p l a n t s (46,47). T h i s behaviour was a t t r i b u t e d t o the f a c t t h a t lower c o n c e n t r a t i o n s o f auxins s t i m u l a t e r i b o n u c l e a s e s y n t h e s i s , whereas the h i g h e r c o n c e n t r a t i o n s i n h i b i t the s y n t h e s i s of t h i s enzyme (87). Thus, i t was suggested t h a t the i n c r e a s e i n RNA c o u l d be due t o r e s i s t a n c e t o degradation r a t h e r than to an i n c r e a s e i n s y n t h e s i s (46,47). Key and Key and Shannon have shown t h a t the i n c r e a s e i n RNA due to auxin a p p l i c a t i o n i s composed - 49 -m a i n l y o f r i b o s o m a l RNA. T h i s c o n c l u s i o n was c o n f i r m e d by s e d i m e n t a t i o n c o n s t a n t s and base c o m p o s i t i o n (c,35,45,49). The above e v i d e n c e s t r o n g l y s u g g e s t s t h a t a u x i n t y pe growth r e g u l a t o r s do, i n f a c t , s t i m u l a t e p r o t e i n s y n t h e s i s i n g e n e r a l , r a t h e r t h a n a c t i n g on any s p e c i f i c p a r t o f the whole system. I f ribosomal-RNA i s t h e o n l y f r a c t i o n t h a t i s i n c r e a s e d i t c o u l d p o s s i b l y enhance the s t a b i l i t y o f the e x i s t i n g ribosomes o r i n c r e a s e t h e i r r e s i s t a n c e t o breakdown. F o r t h i s r e a s o n one c o u l d e xpect a more e f f i c i e n t use o r a l o n g e r use o f the p r o t e i n s y n t h e s i z i n g system. Trewas (94,95) on the o t h e r hand has shown t h a t 2,4-D d i d i n c r e a s e some messenger-RNA t h a t was i n low c o n c e n t r a t i o n i n t h e u n t r e a t e d c o n t r o l . A change i n m-RNA, b e i n g the t e m p l a t e f o r p r o t e i n s y n t h e s i s , c o u l d p o s s i b l y b r i n g about a p r o d u c t i o n o f s p e c i f i c p r o t e i n depending upon the m-RNA a f f e c t e d . Changes i n the p r o t e i n f r a c t i o n a f t e r t r e a t m e n t w i t h t h e a u x i n t y p e r e g u l a t o r s 2,4-D and p i c l o r a m c o u l d be seen i n t h i s l i g h t i . e . changes i n RNA. However, i t i s not p o s s i b l e t o a t t r i b u t e t h e changes t o any s p e c i f i c RNA e f f e c t u s i n g the d a t a a v a i l a b l e i n t h i s s t u d y . The i n c r e a s e d p r o t e i n o f a s p e c i f i c band i n Mani t o u and Pembina and not i n S e l k i r k f o l l o w i n g the b r o m o x y n i l t r e a t m e n t s c o u l d r e s u l t from a m o d i f i c a t i o n o f gene a c t i o n brought about by th e c h e m i c a l . - 50 -The order of sensitivity to bromoxynil as indicated by the chromoscan. record of the protein bands was Selkirk < Pembina < Manitou, the last being the most sensitive. Selkirk and Pembina share a 50% common heritage and approximately 5 0% of the background of Pembina and Manitou is similar. Thus, a possible genetic basis exists for the behaviour of the three varieties. I - 51 -CONCLUSIONS The three h e r b i c i d e s 2,4-D, bromoxynil and p i c l o r a m used on thr e e v a r i e t i e s of s p r i n g wheat produced an i n v e r s e r e l a t i o n s h i p between the percent p r o t e i n and y i e l d . 2,4-D and p i c l o r a m , the growth r e g u l a t o r type h e r b i c i d e s , showed a low c o n c e n t r a t i o n s t i m u l a t i o n and a hig h c o n c e n t r a t i o n i n h i b i t i o n of y i e l d i n some v a r i e t i e s . Bromoxynil, a contact h e r b i c i d e , on the o t h e r hand decreased the y i e l d with each i n c r e a s e i n a p p l i c a t i o n r a t e . The e f f e c t o f these growth r e g u l a t o r s was to cause v a r i a t i o n s i n the p r o t e i n bands (albumins, g l o b u l i n s and g l u t e n s ) e l e c t r o p h o r e t i c a l l y separated on lh% acrylamide g e l . In. most cases the i n c r e a s e i n the p r o t e i n o f a p a r t i c u l a r band was compensated by decreases i n some o t h e r p r o t e i n bands. There appeared, t o be a r e l a t i o n between the magnitude of e f f e c t on a p r o t e i n band and the g e n e t i c make up of the thre e v a r i e t i e s when bromoxynil was used. A p p e n d i x T a b l e 1 E F F E C T OF H E R B I C I D E S ON PERCENT P R O T E I N , T O T A L P R O T E I N , AND P R O T E I N EXTRACTED AT pH 8 . 3 * AND pH 3 . 5 * S E L K I R K H e r b i c i d e R a t e i n o z / a c r e % P r o t e i n T o t a l P r o t e i n I p H 8 . 3 p H 3 . 5 G r a n d 2 , 4 - D B r o m o x y n i l P i c l o r a m M e a n s 0 + 8 12 16 12 18 24 1 / 4 3 / 8 1 / 2 1 2 . 5 12 . 2 13 . 5 13 .4 12 .9 1 4 . 8 1 4 . 3 1 1 . 9 1 1 . 8 1 3 . 0 12 . 9 0 1 2 . 6 1 5 . 3 1 6 . 5 1 1 . 4 1 1 . 7 1 3 . 2 1 0 . 1 1 2 . 8 1 3 . 1 12 . 0 1 2 . 8 2 1333 1447 1395 1507 1465 1462 1432 1440 1447 1 4 5 5 1418 618 596 636 591 636 641 647 625 635 658 615 cn M A N I T 0 U % P r o t e i n T o t a l P r o t e i n < p H 8 . 3 p H 3 . 5 13 .0 12 . 0 13 . 4 1 2 . 9 1 7 . 3 1 6 . 7 1 8 . 7 13 . 7 1 2 . 0 1 2 . 3 1 4 . 0 6 1 3 . 4 9 . 5 1 0 . 6 1 3 . 6 7 . 7 5 . 2 2 . 2 1 4 . 8 1 0 . 7 1 1 . 1 1 0 . 5 0 1464 1552 1522 1545 1507 1590 1590 1545 1380 1 6 4 7 1522 640 674 674 685 735 797 803 722 674 797 710 P E M B I N A % P r o t e i n 1 1 . 7 T o t a l P r o t e i n (gm) 1 1 . 8 p H 8 . 3 1388 pH 3 . 5 609 1 2 . 3 1 3 . 6 1 2 . 4 1 5 . 6 1 7 . 1 1 7 . 5 1 2 . 4 1 2 . 9 1 3 . 0 1 1 . 6 1 5 . 5 1 0 . 8 1485 1470 1432 606 586 637 8 . 5 6 . 0 2 . 8 1425 1492 1590 600 650 6 7 1 ' P r o t e i n m i c r o g r a m s / m l C F o l i n T e s t ) 1 0 . 4 1 1 . 8 1 3 . 6 1537 1437 1 6 0 5 712 623 405 C o n t r o l 1 3 . 5 3 10 . 5 1 1468 609 BIBLIOGRAPHY A s h t o n , F.M. 1959. E f f e c t o f G i b b e r e l l i n on a b s o r p t i o n , t r a n s l o c a t i o n and d e g r a d a t i o n o f 2,4-D i n r e d k i d n e y bean. Weeds 7: 436-42. B a r b e r , J.T., Wood, H.L. and Steward, F.C. 1967. The s e p a r a t i o n o f the p r o t e i n s o f wheat by a c r y l a m i d e g e l e l e c t r o p h o r e s i s w i t h s p e c i a l r e f e r e n c e t o m o t t l e d and u n m o t t l e d wheat. Can. J . Botany 47: 5-19 . B a s l e r , E. and Nakazawa, K. 196 0 . Some e f f e c t s o f 2,4-D on t h e n u c l e i c a c i d c o n t e n t o f c o t t o n l e a f . P l a n t P h y s i o l . 35: sup. XXVII. B a s l e r , E. 1964. The d e c a r b o x y l a t i o n o f p h e n o x y a c e t i c a c i d h e r b i c i d e s by e x c i s e d l e a v e s o f woody p l a n t s . Weeds 12: 14-16. B l a c k , C C . J r . and Humphreys, T.E. 1962. E f f e c t s o f 2,4-D on enzymes o f g l y c o l y s i s and pentose phosphate c y c l e . P l a n t P h y s i o l . 37: 66-73. Bonner, J . and B a n d u r s k i , R.S. 1952. S t u d i e s o f t h e p h y s i o l o g y , pharmacology and b i o c h e m i s t r y o f t h e a u x i n s . Ann. Review o f P l a n t P h y s i o l . 3: 59-86. Bourke, J.B., B u t t s , J.S. and Fang, S.C. 1962. E f f e c t s o f v a r i o u s h e r b i c i d e s on g l u c o s e m e t a b o l i s m i n r o o t t i s s u e o f garden pea, Pisum s a t i v u m . I . 2,4-D and i t s a n a l o g s . P l a n t P h y s i o l . 37: 233-37. Bradbury, D. and E n n i s , W.B. 1964. C i t e d from " P h y s i o l o g y and B i o c h e m i s t r y o f H e r b i c i d e s . " (Ed. L . J . Audus). Academic P r e s s , N.Y. ( c . f . 104, p. 301). C a r p e n t e r , K. e t aT. 1964. Chemical and b i o l o g i c a l p r o p e r t i e s o f two new h e r b i c i d e s — i o x y n i l and b r o m o x y n i l . Weed Res. 4: 175-95. C a r p e n t e r , W.J. and C h e r r y , J.H. 196 6. E f f e c t o f p r o t e i n i n h i b i t i o n and a u x i n on n u c l e i c a c i d m e t a b o l i s m i n peanut c o t y l e d o n s . P l a n t P h y s i o l . 41: 919-22. - 54 -11. Chrispeels, M.J. and Hanson, J.B. 1962. The increase of RNA content of cytoplasmic p a r t i c u l a t e of soybean hypocotyl induced by 2,4-D. Weeds 10: 123, 12. Cookie, A.R. 1957. Influence of 2,4-D on the uptake of minerals from the woil. Weeds 5: 25. 13. Corbett, J.R. and M i l l e r , C.S. 1966. The persistence of 2,4-D vin cotton when applied with desiccants. Weeds 14: 34-37. 14. Crafts, A.S. 1959. Further studies on comparative mobility of l a b e l l e d herbicides. Plant Physiol. 34: 615-20. 15. Davis et a l . 1965', E f f e c t of picloram on components oF~intermediary metabolism (Abstracted i n Weed abstracts 16: 975, 1966). 16. Dunham, R.S. 1951. In "Plant Growth Substances". Ed. F. Skoog. University of Wisconsin Press. Madison, p. 195-206. 17. Emmes, A.J. 1950. Destruction of phloem i n young bean plants a f t e r treatments with 2,4-D. Am. J. of Botany 37: 840-47. 18. Erickson, L . C , Seely, C I . and Klages, K.H. 1948 . Effects of 2,4-D upon the protein content of wheat. J. of Am. Soc. of Agronomy 41: 6 5 9-70. 19. Fang, S.C. and Butts, J.S. 19 54. Studies i n plant growth metabolism, IV. Comparative effects of 2,4-D and other plant growth regulators on phosphorus metabolism i n bean plant. Plant Physiol. 29: 365-68. 20. Fletcher, W.W. and Smith, I.E. 196 4. The growth of bacteria, fungi and algae i n the presence of 3,5- dihalogen-4^hydroxybenzonitrile with comparative data for substituted aryloxyalkane-carboxylic acids. Proc. B r i t . Weed Cont. Conf. p.. 20. 21. Foy, C L . 1964. Ioxynil: A new weed k i l l e r for use i n cereal grain. Proc. B r i t . Weed Cont, Conf. p. 8 8-9 8. 22. Frank, P.A. and Grisby, B.H. 1957. Effects of h e r b i c i d a l sprays on n i t r a t e accumulation i n certain weed species. Weeds 5: 2 06. F r e e d , V.H., R e i t h e l , F . J . and Remmert, L.F. 1961. Some p h y s i o c h e m i c a l a s p e c t s o f s y n t h e t i c a u x i n w i t h r e s p e c t t o t h e i r mode o f a c t i o n . P l a n t Growth R e g u l a t i o n (Ed. K l e i n ) Iowa S t a t e U n i v e r s i t y P r e s s . Ames, Iowa. p. 289-303. F r e e l a n d , R.O. 1949. E f f e c t o f growth s u b s t a n c e s on p h o t o s y n t h e s i s . P l a n t P h y s i o l . 24: 621-2 8. F r e e l a n d , R.O. 195 0. E f f e c t s o f 2,4-D and o t h e r growth s u b s t a n c e s on p h o t o s y n t h e s i s and r e s p i r a t i o n i n A n a c h a r i s . Bot. Ga;z. I l l : 319-24. F r i e b e r g , S.R. and C l a r k , H.E. 1952. E f f e c t s o f 2,4-D upon t h e n i t r o g e n m e t a b o l i s m and w a t e r r e l a t i o n s o f soybean p l a n t s grown a t d i f f e r e n t n i t r o g e n l e v e l s . B ot. Gaz. 113: 322-333. F r i e b e r g , S.R. and C l a r k , H . E . 1955. Changes i n n i t r o g e n f r a c t i o n s and p r o t e l y t i c enzymes o f soybean p l a n t s t r e a t e d w i t h 2,4-D. P l a n t P h y s i o l . 30: 39-46. F r i e s e n , H.A. 1967. T o l e r a n c e o f two wheat v a r i e t i e s t o recommended h e r b i c i d e t r e a t m e n t s . Res. Report Nat. Weed Com. (West S e c t . ) p. 6. F r i e s e n , H.A. 1967. T o l e r a n c e o f wheat v a r i e t i e s . T h a t c h e r and Park t o post-emergence h e r b i c i d e s . Res. Report Nat. Weed Com. (West S e c t . ) p. 12. F r y e r , J.D. 1956. The e f f e c t o f 2,4-D amine on a c l e a n c e r e a l c r o p . P r o c . B r i t . Weed Cont. Conf. p. 37. F u l t s , J . L . , Hay, R.J. and Payne, M.G. 1952. N i t r a t e c o n t e n t o f Red McClure P o t a t o e s unchanged, by 2,4-D t r e a t m e n t . Am. P o t a t o J . 29: 9 7-9 8. G a l s t o n , A.W. and D a v i s , P . J . 196 9. Hormonal r e g u l a t i o n i n h i g h e r p l a n t s . S c i e n c e 163: 1288-97. G o r t e r , Chr. J . and Van Der Zweep, W. 1964. I n " B i o -c h e m i s t r y and P h y s i o l o g y of. H e r b i c i d e s . " (Ed. L . J . Audus). p. 2 3 5. Hamaker, e t a l . 1963. A p i c o l i n i c a c i d d e r i v a t i v e , a p l a n t growth r e g u l a t o r . S c i e n c e 141: 36 3. Hanson, J.B. and S l i f e , F.W. 1969. Rol e o f RNA me t a b o l i s m i n t h e a c t i o n o f a u x i n h e r b i c i d e . Residue Review 25: 59-67. H a r t , R.H., B i s h o p , J.R. and C o o k i e , A.R. 1964. D i s c o v e r y o f i o x y n i l and i t s development i n U.S. P r o c . B r i t . Weed Cont. Conf. p. 3-9. Hay, J.R., K a r t o c h v i l , D.E. and S t a h l e n , L.M. 1950. Response o f an e a r l y , medium and l a t e m a t u r i n g sorghum t o t r e a t m e n t w i t h 2,4-D made a t 15 d i f f e r e n t s t a g e s o f growth. Res. Report N o r t h C e n t r a l Weed Cont. Conf. 7: 105. Hay, J.R. and Thimann, K.V. 1956. The f a t e o f 2,4-D i n t h e bean s e e d l i n g s . Recovery o f 2,4-D and i t s breakdown i n p l a n t s . P l a n t P h y s i o l . 31: 3 82-87. Hay, J.R. and Thimann, K.V. 1956. The f a t e o f 2,4-D i n bean s e e d l i n g s . I I . T r a n s l o c a t i o n . P l a n t P h y s i o l . 31: 446-451. H e m p h i l l , D.D. 196 8. Performance o f v e g e t a b l e c r o p s on an a r e a t r e a t e d w i t h Tordon h e r b i c i d e . Down t o E a r t h 24: 2 and 24. H e r b i c i d e Handbook o f t h e Weed S o c i e t y o f A m e r i c a . 1967. W.F. Humphrey P r e s s I n c . Geneva, N.Y. p. 12, 77, 95. Heywood, B . J . , C a r p e n t e r , K. and C o t t r e l l , H.J. 19 64. A s t u d y on the c h e m i c a l and b i o l o g i c a l p r o p e r t i e s o f i o x y n i l and b r o m o x y n i l . P r o c . B r i t . Weed Cont. Conf. p. 10-19. H o r t o n , R.F. and F l e t c h e r , A. 196 8. T r a n s p o r t o f a u x i n , p i c l o r a m t h r o u g h p e t i o l e s o f beans and stem s e c t i o n s o f peas. P l a n t P h y s i o l . 43: 2045-48. Humphreys, T.E. and Dugger, W.M. 1957. The e f f e c t o f 2,4-D on pathways o f g l u c o s e c a t a b o l i s m i n h i g h e r p l a n t s . ' P l a n t P h y s i o l . 32: 136-40. Key, J . L . and Hanson, J.B. 1961. Some e f f e c t s o f 2,4-D on s o l u b l e n u c l e o t i d e s and n u c l e i c a c i d s o f soybean s e e d l i n g s . P l a n t P h y s i o l . 36: 145-52. Key, J .L. 1963. S u t i d e s on 2,4-D i n d u c e d changes i n RNA me t a b o l i s m i n e x c i s e d m e s o c o t y l t i s s u e . Weeds 11: 177. Key, J . L . and Shannon, J.C. 1964. Enhancement by a u x i n o f RNA systems i n e x c i s e d soybean h y p o c o t y l t i s s u e . P l a n t P h y s i o l . 39: 360-64. - 57 -48. Key, J.L. 1964. RNA and protein synthesis as ess e n t i a l process f o r c e l l elongation. Plant Physiol. 39: 365-70. 49. Key, J.L. 1969. Hormones and nucleic acid metabolism. Ann. Review of Plant Physiol. 20: 449-74. 50. Kirch, J . , de Wilde, R.C. and William, N.A. 1966. Selective weed control with oxynils i n cereals. Res. Report Nat. Weed Com. (Eastern Sect.), p. 5. 51. Klingman, D.L. 1947. Effects of spraying cereals with 2,4-D. J . of Am. Soc. of Agronomy 40: 445-47. 52. Klingman, D.L. 1953. Effects of varying rates of 2,4-D and 2,4,5-T at d i f f e r e n t stages of growth of winter wheat. Agronomy J. 45: 606-10. 53. Krawiec, S. and Morre, D.J. 196 8. Interaction of Tordon herbicide applied i n combination. Down to Earth 24: 7-11. 54. Kreps, L.B. and A l l e y , H.P. 1967. H i s t o l o g i c a l abnormalities induced by picloram on Canada t h i s t l e roots. Weed Science 15: 56-59. 55. Lawson, H.M. 1964. Selective weed control i n B r i t i s h cereal crop with 4-amino-3,5,6-trichloropicolinic acid. Proc. B r i t . Weed Cont. Conf. p. 12 2. 56. Lee, G.A., Dobrenz, A.K. and A l l e y , H.P. 1967. Preliminary investigation of the e f f e c t of Tordon and 2,4-D on l e a f and root tissue of Canada t h i s t l e . Down to Earth 23: 21-24. 57. Leonard, O.A., Weaver, R.J. and Glenn, R.K. 1967. Eff e c t of 2,4-D and picloram on translocation of C l 4 assimilates i n V i t i s vinefera. Weed Res. 7: 208-219. 58. Leopold, A.C. 1964. Plant growth and development. McGraw H i l l Book Co. N.Y. p. 81-115. 59. Linden, G. 1954. Cited from "Physiology and Biochemistry of Herbicides". B e i t r . B i o l . 30: 343-78. 60. L o t l i k a r , P.D. 1960. Diss. abst. 21: 446-447. - 58 -61. L o t l i k a r , P.D., Remmert, L.E. and F r e e d , V.H. 1968. E f f e c t o f 2,4-D and o t h e r h e r b i c i d e s on o x i d a t i v e p h o s p h o r y l a t i o n i n m i t o c h o n d r i a from cabbage. Weed S c i e n c e 16: 161-64. 62. L o u s t a l o t , A . J . and M u z i k , T.J. 1953. E f f e c t s o f 2,4-D on apparent p h o t o s y n t h e s i s and d e v e l o p m e n t a l morphology o f v e l v e t g r a s s . Bot Gaz. 115: 56-66. 63. Lowry, O.H. e t a l . 19 51. P r o t e i n measurement w i t h F o l i n p h e n o l r e a g e n t . J . B i o l . Chem. 193: 265-75. 64. M a l h o t r a , S.S. 1966. A b e r r a t i o n o f the n u c l e i c a c i d m e t a b o l i s m o f p l a n t s i n d u c e d by 4-amino-3,5,6-t r i c h l o r o p i c o l i n i c a c i d . Ph.D. T h e s i s . U n i v . o f 111. C i t e d from "Role o f RNA m e t a b o l i s m i n t h e a c t i o n o f a u x i n h e r b i c i d e , " Hanson, J.B. and S l i f e , F.W. ( c . f . 3 5 ) . 65. Mindreboe, K .J. 1966. Performance o f h e r b i c i d e i n f a l l wheat. Res. Report Nat. Weed Com. ( E a s t e r n S e c t . ) p. 6. 66. M o l b e r g , E.S. 1967. T o l e r a n c e o f wheat t o 2,4-D and MCPA. Res. Report Nat. Weed Com. (Western S e c t . ) p. 23. 67. Morgan, P.W. and H a l l , W.C. 1963. M e t a b o l i s m o f 2,4-D by c o t t o n and g r a i n sorghum. Weeds 11: 130. 68. Nooden, L.D. 1968. S t u d i e s on t h e r a t e o f RNA s y n t h e s i s i n a u x i n i n d u c t i o n o f c e l l enlargement. P l a n t P h y s i o l . 43: 140-50. 69. N o r r i s , L.A. and M o r r i s , R.O. 1969. P r o t e i n m e t a b o l i s m as i n f l u e n c e d by growth r e g u l a t o r c h e m i c a l i n p l a n t s . Western Soc. o f Weed S c i e n c e Res. P r o g r e s s R e p o r t . Las Vegas, Nevada, p. 10 3. 70. Ormrod, D.P. and W i l l i a m , M.K. 1960. Phosphorous m e t a b o l i s m o f T r i f o l i u m h i r t u m as a f f e c t e d by 2,4-D and g i b b e r e l l i n . P l a n t P h y s i o l . 35: 81-87. 71. O r n s t e i n , L. and D a v i s , B.J. D i s c e l e c t r o p h o r e s i s r e p r i n t by D i s t i l l a t i o n P r o d u c t s I n d u s t r i e s . (Eastman Kodak Co.) R o c h e s t e r , N.Y. ( c . f . #2). 72. Osborne, D.J. and H a l l a w a y , H.M. 1964. The a u x i n , 2,4-D as a r e g u l a t i o n o f p r o t e i n s y n t h e s i s and senescence i n d e t a c h e d l e a v e s o f prunes. New P h y t o l o g i s t 63: 334-47. - 59 -73. P a t o n , D. and S m i t h , J.E. 196 5. The e f f e c t o f 4-hydroxy-3 , 5 - d i i o d o b e n z o n i t r i l e on CO2 f i x a t i o n , ATP f o r m a t i o n and NADP r e d u c t i o n i n c h l o r o p l a s t o f V i c i a f a b a L. Weed Res. 5: 75-77. 74. P h i l i p s , W.M. 1957. The e f f e c t o f 2,4-D on y i e l d on M i d l a n d g r a i n sorghum. Weeds 6: 271-280. 75. P h i l i p s , W.M. e t a l . 1967. Response and a n a l y s i s o f wheat f o l l o w i n g l a t e p r e - h a r v e s t a p p l i c a t i o n o f 2,4-D. Weed S c i e n c e 15: 107. 76. P i n t h u s , M.J. and N a t o w i t z , Y. 1967. Response o f s p r i n g wheat t o a p p l i c a t i o n o f 2,4-D a t v a r i o u s growth s t a g e s . Weed Res. 7: 95-101. 77. R a t k i n ? Y.V. and Po t a p o v a , 1964. I n " P h y s i o l o g y and B i o c h e m i s t r y o f H e r b i c i d e s . " (Ed. L . J . Audus). Academic P r e s s , ( c . f . 104, p. 301). 78. Ray, P.M. and R u f s i n k , A.W. 1962. K i n e t i c e x periment on the n a t u r e o f the growth mechanism i n o a t c o l e o p t i l e c e l l s . Developmental B i o l . 4: 377. 79. R e b s t o c k , T.L., Hamner, G.L. and S e l l , H.M. 1954. The i n f l u e n c e o f 2,4-D on t h e phosphorus m e t a b o l i s m o f c r a n b e r r y bean p l a n t s ( P h a s e o l u s v u l g a r i s ) . P l a n t P h y s i o l . 29: 490-91. 80. Redemann, C T . e t a l . 1968. The f a t e o f 4-amino-3,5,6-t r i c h l o r o p i c o l m i c a c i d i n s p r i n g wheat and s o i l . B u l l e t i n o f E n v i r o n m e n t a l C o n t a m i n a t i o n and T o x i c o l o g y 3:80-96. 81. R e i s f i e l d , R.A. e t a l . 1962. D i s k e l e c t r o p h o r e s i s o f b a s i c p r o t e i n s and p e p t i d e s on p o l y a c r y l a m i d e g e l s . N a ture 195: 281-83. 82. Rhodes, A. 1952. The i n f l u e n c e o f the p l a n t growth r e g u l a t o r , MCPA, on t h e m e t a b o l i s m o f c a r b o h y d r a t e , n i t r o g e n and m i n e r a l s i n tomato. J . Exp. Bot. 8: 129-54. 83. R i t t y , P.M. 1964. 4 - a m i n o - 3 , 5 ? 6 - t r i c h l o r o p i c o l i n i c a c i d . A new s y s t e m i c h e r b i c i d e u s e f u l f o r t h e c o n t r o l o f many w o r l d wide v e g e t a t i v e problems. P r o c . B r i t . Weed Cont. Conf. p. 23. 84. R o j a s - G a r c i d u e n a s , M. and Kommedhal Thor. 1958. The e f f e c t s o f 2,4-D on r a d i c l e development and stem anatomy o f soybean. Weeds 6: 49. - 60 -85. S c i f e r s , C.J. and McCa r t y , M.K. 196 8. R e a c t i o n o f w e s t e r n ironweed l e a f t i s s u e t o p i c l o r a m . Weed S c i e n c e 16: 347-49. 86. S e l l , H.M. e t a l . 1949. Changes i n c h e m i c a l c o m p o s i t i o n o f t h e stems o f r e d k i d n e y bean p l a n t s t r e a t e d w i t h 2,4-D. P l a n t P h y s i o l . 24: 295-99. 87. Shannon, J.C., Hanson, J.B. and W i l s o n , C M . 1964. R i b o n u c l e a s e l e v e l s i n t h e m e s o c o t y l t i s s u e o f Zea mays as a f u n c t i o n o f 2,4-D a p p l i c a t i o n . P l a n t P h y s i o l . 39: 804-809. 88. Sigmund, S. 1968. I n h i b i t i o n o f i n v i t r o DNA s y n t h e s i s by a u x i n . P l a n t P h y s i o l . 43: 1008-1010. 89. S l i f e , F.W. e t a l . 1962. P e n e t r a t i o n , t r a n s l o c a t i o n and me t a b o l i s m o f 2,4-D, 2,4,5-T i n w i l d and c u l t i v a t e d cucumber. Weeds 10: 29-32. 90. S m i t h , F.G. 1951. I n " P l a n t Growth S u b s t a n c e s " (Ed. F. Skoog). U n i v . o f W i s c o n s i n P r e s s . Madison, p. 111-119. 91. Steward, F.C., Lyndon, R.F. and B a r b e r , J.T. 196 5. A c r y l a m i d e g e l e l e c t r o p h o r e s i s o f s o l u b l e p l a n t p r o t e i n s . A st u d y on pea s e e d l i n g s i n r e l a t i o n t o development. Am. J . Bot 52: 155-64. 92. Swanson, C R . and Shaw, W.C 1954. The e f f e c t o f 2,4-D on t h e h y d r o c y a n i c a c i d and n i t r a t e c o n t e n t o f Sudan g r a s s . Agronomy J . 46: 418-21. 93. S w i t z e r , C M . 1957. E f f e c t o f h e r b i c i d e s and r e l a t e d c h e m i c a l s on o x i d a t i o n and p h o s p h o r y l a t i o n by i s o l a t e d soybean m i t o c h o n d r i a . P l a n t P h y s i o l . 32: 42-44. 94. Trewas, A.S. 1968. The e f f e c t o f 3 - I n d o l y l a c e t i c a c i d on t h e l e v e l s o f polysomes i n e t i o l a t e d pea t i s s u e . P h y t o c h e m i s t r y 7: 67 3. 95. Trewas, A.S. 1968. E f f e c t o f IAA on RNA and p r o t e i n s y n t h e s i s : E f f e c t o f IAA on t h e m e t a b o l i s m o f RNA and p r o t e i n i n e t i o l a t e d s u b a p i c a l s e c t i o n s o f Pisum s a t i v u m . A r c h i v e s o f B i o c h e m i s t r y and B i o p h y s i c s . 123: 3 24. - 61 -96. Van d e r Zweep, W. 1961. The movement o f l a b e l l e d 2,4-D i n young b a r l e y p l a n t s . Weed Res. 1: 258-66. 97. Wain, R.L. 1964. I o x y n i l : Some c o n s i d e r a t i o n on i t s mode o f a c t i o n . P r o c . B r i t . Weed Cont. Conf. p. 308-11. 98. Wedding, R.T. and B l a c k , M.K. 196 7. U n c o u p l i n g o f p h o s p h o r y l a t i o n i n c h l o r e l l a by 2,4-D. P l a n t and S o i l 14: 242-48. 99. W e l l e r , L.E. ? B a l l , C D . and S e l l , H.M. 1957. S t u d i e s o f m a l e i c h y d r a z i d e i n t e r a c t i o n w i t h t h i o l compounds. P l a n t P h y s i o l . 32: 146. 100. West, S.H., Hanson, I.B. and Key, J.L. 1960. E f f e c t o f 2,4-D on n u c l e i c a c i d and p r o t e i n c o n t e n t o f s e e d l i n g t i s s u e (cucumber). Weeds 8: 333-40. 101. W i l l i a m , G. and Dunn, S. 1961. R e l a t i o n o f l i g h t q u a l i t y t o e f f e c t s o f 2,4-D on c h l o r o p h y l l and C0? exchange. Weeds 9: 243. 102. Wolf, D.E. e t a l . 19 50. E f f e c t o f 2,4-D on c a r b o h y d r a t e and n u t r i e n t element c o n t e n t and on r a p i d i t y o f k i l l o f soybean p l a n t s growing a t d i f f e r e n t n i t r o g e n l e v e l s . Bot. Gaz. 112: 188-97. 103. Wort, D.J. 1951. E f f e c t o f n o n - l e t h a l c o n c e n t r a t i o n s o f 2,4-D on buckwheat. P l a n t P h y s i o l . 26: 50-58. 104. Wort, D.J. 1964. I n " P h y s i o l o g y and B i o c h e m i s t r y o f H e r b i c i d e s . " (Ed. L . J . Audus). Academic P r e s s . N.Y. p. 291-342. 105. Yasuda, G.K., Payne, M.G. and F u l t s , J .L. 1955. E f f e c t o f 2,4-D and m a l e i c h y d r a z i d e on p o t a t o p r o t e i n s as shown by paper e l e c t r o p h o r e s i s . Nature 176: 1029-30. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0102104/manifest

Comment

Related Items