title: Molecular basis of ALS- and/or ACCase-inhibitor resistance in shortawn foxtail (Alopecurus aequalis Sobol.).
abstract: Alopecurus aequalis, a predominant weed species in wheat and oilseed rape fields, can no longer be controlled by mesosulfuron-methyl application after continuous use over several years. Based on dose-response studies, the putative resistant populations, JTJY-1 and JHHZ-1, were found to be resistant to mesosulfuron-methyl, with resistance index values of 5.5 and 14, respectively. Sensitivity assays of the mesosulfuron-methyl-resistant populations to other herbicides revealed that the JTJY-1 population had moderate or high cross resistance to sulfonylureas (SUs) and triazolopyrimidines (TPs), but displayed a low level resistance to imidazolinones (IMIs). JTJY-1 also had high multi-resistance to ACCase inhibitors, but remained susceptible to photosystem II inhibitors. The JHHZ-1 population was resistant to all ALS inhibitors tested, but was sensitive to ACCase inhibitors and photosystem II inhibitors. To clarify the molecular basis of resistance in JTJY-1 and JHHZ-1 population, the ALS and ACCase gene were sequenced. Two ALS mutations (Pro-197-Thr or Trp-574-Leu) were detected in the mesosulfuron-methyl-resistant plants. The ACCase gene analysis revealed that the resistant JTJY-1 population had an Ile-1781-Leu mutation. Furthermore, the presence of two different target site resistance (TSR) mechanisms (ALS and ACCase mutations) existing simultaneously in individual A. aequalis was firstly documented in the presented study.
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, Beijing, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Xia
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, Beijing, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Pan
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, Beijing, 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, Beijing, China.
authors.forename: Qiong
authors.initials: Q
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, Beijing, China.
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Feng
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, Beijing, China. Electronic address: dly@njau.edu.cn.
authors.forename: Liyao
authors.initials: L
authors.lastname: Dong
mesh_terms: D000095:Acetolactate Synthase / Q000037:antagonists & inhibitors* / Q000235:genetics; D000103:Acetyl-CoA Carboxylase / Q000037:antagonists & inhibitors / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D053209:Herbicide Resistance / Q000235:genetics*; D006540:Herbicides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D006109:Poaceae / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D013453:Sulfonylurea Compounds / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D013453:Sulfonylurea Compounds; C521745:mesosulfuron-methyl; D000095:Acetolactate Synthase; D000103:Acetyl-CoA Carboxylase
keywords: ACCase mutation; ALS mutation; Alopecurus aequalis; Cross-resistance; Mesosulfuron-methyl; Target-site resistance