Quinclorac Resistance in Echinochloa crus-galli from China
Peng Qiong,
Han Heping,
Yang Xia,
Bai Lianyang,
Yu Qin,
Stephen B. Powles
Affiliations
Peng Qiong
Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Collaborative Innovation Center for Field Weeds Control, Hunan University of Humanities, Science and Technology, Loudi 417000, China; Australian Herbicide Resistance Initiative, School of Agriculture and Environment, University of Western Australia, WA 6009, Australia
Han Heping
Australian Herbicide Resistance Initiative, School of Agriculture and Environment, University of Western Australia, WA 6009, Australia
Yang Xia
Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Bai Lianyang
Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Collaborative Innovation Center for Field Weeds Control, Hunan University of Humanities, Science and Technology, Loudi 417000, China
Echinochloa crus-galli is a major weed in rice fields in China, and quinclorac has been long used for its control. Over-reliance of quinclorac has resulted in quinclorac resistance in E. crus-galli. Two resistant (R) E. crus-galli populations from Hunan, China were confirmed to be at least 78-fold more resistant to quinclorac than the susceptible (S) population. No difference in foliar uptake of 14C-labelled quinclorac was detected between the R and S plants. However, a higher level of 14C translocation and a lower level of quinclorac metabolism were found in the R plants. Basal and induced expression levels of β-cyanoalanine synthase (β-CAS) gene and β-CAS activity were not significantly different between the R and S plants. However, the induction expression of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO1) gene by quinclorac treatment was evident in the S plants but not in the R plants. Quinclorac resistance in the two resistant E. crus-galli populations was not likely to be related to foliar uptake, translocation or metabolism of quinclorac, nor to cyanide detoxification via β-CAS. Thus, target-site based quinclorac signal reception and transduction and regulation of the ethylene synthesis pathway should be the focus for further research. Keywords: Echinochloa crus-galli, Quinclorac resistance, Quinclorac metabolism, β-cyanoalanine synthase, 1-aminocyclopropane-1-carboxylic acid synthase, 1-aminocyclopropane-1-carboxylic acid oxidase, Rice
