Nicotine metabolism in the cabbage looper Trichoplusia ni (Hübner) - a toxicogenomic approach
department or school: Science, Irving K. Barber Faculty of (Okanagan)
department or school: Biology, Department of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Hassanpour Farshour, Nazli
issued: 2021-06-23T22:01:35Z
issued: 2021
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: The cabbage looper, Trichoplusia ni (T. ni) is a generalist insect (Lepidoptera: Noctuidae) that is an agricultural pest of crucifers and other crops of economic importance. In fact, over 70% of all agricultural pest insects are Lepidopterans. Although insecticides are effective at controlling insect populations by targeting the nervous system, they can have negative off-target effects. Cytochrome P450s (CYPs), glutathione S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), and carboxylesterases (CEs) are metabolic enzymes frequently implicated in insecticide resistance. These enzymes work in concert with transport genes such as ATP-binding cassette transporters (ABCs), organic cation transporters (OCTs) and multidrug resistance proteins (MRPs). Upregulation of detoxification enzymes and inhibited binding of insecticides due to target-site mutations are the main mechanisms causing insecticide resistance. Enriched metabolic detoxification of xenobiotics along with the subsequent development of insecticide resistance have been linked to the overexpression of CYPs in insects. Previous studies have suggested that generalist insect herbivores’ (e.g. T. ni) growth and development are inhibited by exposure to the plant alkaloid nicotine, whereas specialist insect herbivores (e.g. tobacco hornworm) are not affected. However, it has been shown that the Malpighian (renal) tubules of T. ni actively excrete nicotine. Recent research has shown that T. ni do in fact detoxify nicotine into the three major metabolites; cotinine, cotinine-N- oxide, and nicotine-N-oxide. The objective of this thesis was to utilize next-generation sequencing methods to establish a greater understanding of how nicotine, a model plant alkaloid, is detoxified by a generalist insect such as T. ni. This thesis showed that dietary nicotine exposure in T. ni resulted in the increased expression of a number of metabolic detoxification and transport-related gene candidates. CYPs in particular showed in…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/78772
note: NICOTINE METABOLISM IN THE CABBAGE LOOPER TRICHOPLUSIA NI (HÜBNER) – A TOXICOGENOMIC APPROACH by Nazli Hassanpour Farshour B.Sc., The University of British Columbia, 2018 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Biology) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) June 2021 © Nazli Hassanpour Farshour, 2021 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: NICOTINE METABOLISM IN THE CABBAGE LOOPER TRICHOPLUSIA NI (HÜBNER) – A TOXICOGENOMIC APPROACH submitted by Nazli Hassanpour Farshour in partial fulfillment of the requirements of the degree of Master of Science. Mark Rheault, Biology, Irving K. Barber Faculty of Science Supervisor Michael Deyholos, Biology, Irving K. Barber Faculty of Science Supervisory Committee Member David Theilmann, Agriculture and Agri-Food Canada Supervisory Committee Member Isaac Li, Biochemistry and Molecular Biology, Chemistry, Irving K. Barber Faculty of Science University Examiner iii Abstract The cabbage looper, Trichoplusia ni (T. ni) is a generalist insect (Lepidoptera: Noctuidae) that is an agricultural pest of crucifers and other crops of economic importance. In fact, over 70% of all agricultural pest insects are Lepidopterans. Although insecticides are effective at controlling insect populations by targeting the nervous system, they can have negative off-target effects. Cytochrome P450s (CYPs), glutathione S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), and carboxylesterases (CEs) are metabolic enzymes frequently implicated in insecticide resistance. These enzymes work in concert with transport genes such as ATP-binding cassette transporters (ABCs), organic cation transporters (OCTs) and multidrug resistance proteins (MRPs). Upregulation of detoxification enzymes and inhibited binding of insecticides due to target-site mu…
has type: Thesis/Dissertation
date issued: 2021-09
is shown at: 10.14288/1.0398502
language: eng
degree discipline: Biology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Rheault, Mark
type: Text
identifier URI: http://hdl.handle.net/2429/78772