title: Mechanism of resistance to fenoxaprop in Japanese foxtail (Alopecurus japonicus) from China.
abstract: Japanese foxtail is one of the most common and troublesome weeds infesting cereal and oilseed rape fields in China. Repeated use during the last three decades of the ACCase-inhibiting herbicide fenoxaprop-P-ethyl to control this weed has resulted in the occurrence of resistance. Dose-response tests established that a population (AHFD-1) from eastern China had evolved high-level resistance to fenoxaprop-P-ethyl. Based on the resistance index, this resistant population of A. japonicus is 60.31-fold resistant to fenoxaprop-P-ethyl. Subsequently, only a tryptophan to cysteine substitution was identified to confer resistance to fenoxaprop-P-ethyl in this resistant population. ACCase activity tests further confirmed this substitution was linked to resistance. This is the first report of the occurrence of Trp-2027-Cys substitution of ACCase in A. japonicus. From whole-plant pot dose-response tests, we confirmed that this population conferred resistance to other APP herbicides, including clodinafop-propargyl, fluazifop-P-butyl, quizalofop-P-ethyl, haloxyfop-R-methyl, cyhalofop-butyl, metamifop, DEN herbicide pinoxaden, but not to CHD herbicides clethodim, sethoxydim. There was also no resistance observed to ALS-inhibiting herbicides sulfosulfuron, mesosulfuron-methyl, flucarbazone-sodium, pyroxsulam, Triazine herbicide prometryne and glyphosate. However, this resistant population was likely to confer slightly (or no) resistant to Urea herbicides chlortoluron and isoproturon.
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Pest Management on Crops in East China (Nanjing Agricultural University), Ministry of Agriculture, China.
authors.forename: Hongle
authors.initials: H
authors.lastname: Xu
authors.affiliation: College of Science, Nanjing Agricultural University, Jiangsu Key Laboratory of Pesticide Science, Nanjing 210095, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Pest Management on Crops in East China (Nanjing Agricultural University), Ministry of Agriculture, China.
authors.forename: Hongchun
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Pest Management on Crops in East China (Nanjing Agricultural University), Ministry of Agriculture, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Integrated Pest Management on Crops in East China (Nanjing Agricultural University), Ministry of Agriculture, China. Electronic address: dly@njau.edu.cn.
authors.forename: Liyao
authors.initials: L
authors.lastname: Dong
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002681:China; D003545:Cysteine / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D053209:Herbicide Resistance / Q000235:genetics; D006540:Herbicides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010080:Oxazoles / Q000494:pharmacology*; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D057685:Plant Weeds / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006109:Poaceae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D011422:Propionates / Q000494:pharmacology*; D014364:Tryptophan / Q000235:genetics
chemical_list: D018744:DNA, Plant; D006540:Herbicides; D010080:Oxazoles; D010940:Plant Proteins; D011422:Propionates; C416661:fenoxaprop ethyl; D014364:Tryptophan; D000103:Acetyl-CoA Carboxylase; D003545:Cysteine
keywords: Acetyl-CoA carboxylase; Amino acid substitution; Cross-resistance; Herbicide resistance