title: The role of cytochrome P450 monooxygenase in the different responses to fenoxaprop-P-ethyl in annual bluegrass (Poa annua L.) and short awned foxtail (Alopecurus aequalis Sobol.).
abstract: Herbicide resistance or tolerance in weeds mediated by cytochrome P450 monooxygenase is a considerable problem. However, cytochrome P450 mediated resistance or tolerance in weeds was less studied. Thus, in this work, the role of the cytochrome P450 monooxygenase in the different responses of Poa annua and Alopecurus aequalis to fenoxaprop-P-ethyl was studied. We found that the effect of fenoxaprop-P-ethyl could be synergized by piperonyl butoxide (PBO) in P. annua, but not by malathion. After being treated with fenoxaprop-P-ethyl (containing mefenpyr-diethyl), the contents of cytochrome P450 and cytochrome b5 in P. annua increased significantly compared to plants treated with mefenpyr-diethyl only or untreated plants. However, the increase was less in A. aequalis, which was susceptible to fenoxaprop-P-ethyl. The activities of ρ-nitroanisole O-demethylase (PNOD), ethoxyresorufin O-deethylase (EROD), ethoxycoumarin oxidase (ECOD) and NADPH-dependent cytochrome P450 reductase mediated by cytochrome P450 monooxygenase increased in P. annua after treatment with fenoxaprop-P-ethyl, especially the activities of ECOD and cytochrome P450 reductase. Besides this, cytochrome P450 monooxygenase activity toward fenoxaprop-P-ethyl in P. annua increased significantly compared to untreated or treated with mefenpyr-diethyl plants and treated or untreated A. aequalis. Cytochrome P450 monooxygenase may play an important role in the different responses to fenoxaprop-P-ethyl in P. annua and A. aequalis.
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, Nanjing 210095, China; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Hongchun
authors.initials: H
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Bo
authors.initials: B
authors.lastname: Lv
authors.forename: Yuanlai
authors.initials: Y
authors.lastname: Lou
authors.forename: Liyao
authors.initials: L
authors.lastname: Dong
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D010080:Oxazoles / Q000494:pharmacology; D010882:Piperonyl Butoxide / Q000378:metabolism; D031785:Poa / Q000187:drug effects / Q000201:enzymology*; D006109:Poaceae / Q000187:drug effects / Q000201:enzymology*; D011422:Propionates / Q000494:pharmacology
chemical_list: D010080:Oxazoles; D011422:Propionates; C416661:fenoxaprop ethyl; D003577:Cytochrome P-450 Enzyme System; D010882:Piperonyl Butoxide
keywords: Alopecurus aequalis; Cytochrome P450 monooxygenase; Fenoxaprop-P-ethyl; Poa annua