title: Target-site resistance to bensulfuron-methyl in Sagittaria trifolia L. populations.
abstract: Sagittaria trifolia L. is one of the most serious weeds in paddy fields in northeast of China and cannot be controlled effectively by bensulfuron-methyl in recent years. In this study, two suspected resistant S. trifolia populations (R1 and R2) were collected in Liaoning province of China. Whole-plant dose-response studies showed that R1 and R2 were highly resistant to bensulfuron-methyl, with the GR50 R/S ratios of 76.99 and 49.94 respectively. In vitro acetolactate synthase (ALS) assays revealed that resistance was due to reduced sensitivity of the ALS to bensulfuron-methyl inhibition, with I50 R/S ratios of 81.86 and 67.48 for R1 and R2, respectively. Total ALS activity was similar for the S and R2 populations, whereas the R1 population displayed significantly higher ALS activity than did the S population. The mutations Pro-197-Leu and Pro-197-Ser were identified in the ALS gene of the R1 and R2 populations, respectively. This is the first report examining bensulfuron-resistant S. trifolia in Liaoning province, China. The Pro197 mutation is likely responsible for resistance to bensulfuron-methyl in S. trifolia populations.
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Songhong
authors.initials: S
authors.lastname: Wei
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Pingsheng
authors.initials: P
authors.lastname: Li
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China. Electronic address: jimingshan@163.com.
authors.forename: Mingshan
authors.initials: M
authors.lastname: Ji
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Dong
authors.affiliation: College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Haining
authors.initials: H
authors.lastname: Wang
mesh_terms: D000095:Acetolactate Synthase / Q000235:genetics; D053209:Herbicide Resistance / Q000235:genetics; D006540:Herbicides / Q000633:toxicity*; D034903:Sagittaria / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D013453:Sulfonylurea Compounds / Q000633:toxicity*
chemical_list: D006540:Herbicides; D013453:Sulfonylurea Compounds; C071475:methyl bensulfuron; D000095:Acetolactate Synthase
keywords: Acetolactate synthase enzyme; Acetolactate synthase-resistance mutation; Herbicide resistance; Sagittaria trifolia L.