title: Climate change increases the risk of herbicide-resistant weeds due to enhanced detoxification.
abstract: Global warming will increase the incidence of metabolism-based reduced herbicide efficacy on weeds and, therefore, the risk for evolution of non-target site herbicide resistance. Climate changes affect food security both directly and indirectly. Weeds are the major biotic factor limiting crop production worldwide, and herbicides are the most cost-effective way for weed management. Processes associated with climatic changes, such as elevated temperatures, can strongly affect weed control efficiency. Responses of several grass weed populations to herbicides that inhibit acetyl-CoA carboxylase (ACCase) were examined under different temperature regimes. We characterized the mechanism of temperature-dependent sensitivity and the kinetics of pinoxaden detoxification. The products of pinoxaden detoxification were quantified. Decreased sensitivity to ACCase inhibitors was observed under elevated temperatures. Pre-treatment with the cytochrome-P450 inhibitor malathion supports a non-target site metabolism-based mechanism of herbicide resistance. The first 48 h after herbicide application were crucial for pinoxaden detoxification. The levels of the inactive glucose-conjugated pinoxaden product (M5) were found significantly higher under high- than low-temperature regime. Under high temperature, a rapid elevation in the level of the intermediate metabolite (M4) was found only in pinoxaden-resistant plants. Our results highlight the quantitative nature of non-target-site resistance. To the best of our knowledge, this is the first experimental evidence for temperature-dependent herbicide sensitivity based on metabolic detoxification. These findings suggest an increased risk for the evolution of herbicide-resistant weeds under predicted climatic conditions.
authors: The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, 7610001, Rehovot, Israel.
authors: Maor
authors: M
authors: Matzrafi
authors: Department of Analytical Chemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.
authors: Bettina
authors: B
authors: Seiwert
authors: Department of Analytical Chemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.
authors: Thorsten
authors: T
authors: Reemtsma
authors: The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, 7610001, Rehovot, Israel.
authors: Baruch
authors: B
authors: Rubin
authors: The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, 7610001, Rehovot, Israel. zvi.peleg@mail.huji.ac.il.
authors: Zvi
authors: http://orcid.org/0000-0001-8063-1619
authors: Z
authors: Peleg
mesh_terms: D057231:Climate Change; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism; D053209:Herbicide Resistance; D006540:Herbicides / Q000378:metabolism; D006574:Heterocyclic Compounds, 2-Ring / Q000378:metabolism; D008658:Inactivation, Metabolic; D008129:Lolium / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D057685:Plant Weeds / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D006109:Poaceae / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D013696:Temperature
chemical_list: D055768:Halogenated Diphenyl Ethers; D006540:Herbicides; D006574:Heterocyclic Compounds, 2-Ring; C012891:dichlorfop-methyl; C542519:pinoxaden
keywords: Diclofop-methyl; Global warming; Herbicide metabolism; Non-target-site resistance; Temperature-dependent sensitivity; Weed management