title: A novel Pro197Glu substitution in acetolactate synthase (ALS) confers broad-spectrum resistance across ALS inhibitors.
abstract: Water chickweed (Myosoton aquaticum L.), a competitive broadleaf weed, is widespread in wheat fields in China. Tribenuron and pyroxsulam failed to control water chickweed in the same field in Qiaotian Village in 2011 and 2012, respectively. An initial tribenuron resistance confirmation test identified a resistant population (AH02). ALS gene sequencing revealed a previously unreported substitution of Glu for Pro at amino acid position 197 in resistant individuals. A purified subpopulation (WRR04) that was individually homozygous for the Pro197Glu substitution was generated and characterized in terms of its response to different classes of ALS inhibitors. A whole-plant experiment showed that the WRR04 population exhibited broad-spectrum resistance to tribenuron (SU, 318-fold), pyrithiobac sodium (PTB, > 197-fold), pyroxsulam (TP, 81-fold), florasulam (TP, > 36-fold) and imazethapyr (IMI, 11-fold). An in vitro ALS assay confirmed that the ALS from WRR04 showed high resistance to all the tested ALS inhibitors. These results established that the Pro197Glu substitution endows broad-spectrum resistance across ALS inhibitors in water chickweed. In addition, molecular markers were developed to rapidly identify the Pro197Glu mutation.
authors.affiliation: Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China.
authors.forename: Weitang
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China.
authors.forename: Guohui
authors.initials: G
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China.
authors.forename: Long
authors.initials: L
authors.lastname: Du
authors.affiliation: Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China.
authors.forename: Wenlei
authors.initials: W
authors.lastname: Guo
authors.affiliation: College of Chemistry and Pharmacy Science, Qingdao Agricultural University, Qingdao 266109, Shandong, China.
authors.forename: Lingxu
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Plant Science, Anhui Science and Technology University, Fengyang 233100, Anhui, China.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Bi
authors.affiliation: Key Laboratory of Pesticide Toxicology and Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China. Electronic address: wangjx@sdau.edu.cn.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Wang
mesh_terms: D000095:Acetolactate Synthase / Q000037:antagonists & inhibitors / Q000235:genetics*; D019943:Amino Acid Substitution; D001190:Arylsulfonates / Q000494:pharmacology; D001483:Base Sequence; D001565:Benzoates / Q000494:pharmacology; D029748:Caryophyllaceae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D053209:Herbicide Resistance / Q000235:genetics*; D006540:Herbicides / Q000494:pharmacology; D009539:Nicotinic Acids / Q000494:pharmacology; D057685:Plant Weeds / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011743:Pyrimidines / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D001190:Arylsulfonates; D001565:Benzoates; D018744:DNA, Plant; D006540:Herbicides; D009539:Nicotinic Acids; D011743:Pyrimidines; D013449:Sulfonamides; C413390:florasulam; C050296:metsulfuron methyl; C401888:pyrithiobac sodium; C093630:imazethapyr; D000095:Acetolactate Synthase
keywords: (d)CAPS; ALS inhibitor; ALS resistance mutation; Cross-resistance; Water chickweed (Myosoton aquaticum (L.) Moench.)