Molecular bases for resistance to acetyl-coenzyme A carboxylase inhibitor in Japanese foxtail (Alopecurus japonicus)

作者：Tang, Huaiwu; Li, Jun; Dong, Liyao^*; Dong, Aibin; Lu, Bo; Zhu, Xudong

来源：Pest Management Science, 2012, 68(9): 1241-1247.

DOI：10.1002/ps.3285

• acetyl-CoA carboxylase
• herbicide resistance
• Alopecurus japonicus
• haloxyfop-R-methyl
• amino acid substitution

BACKGROUND: Haloxyfop-R-methyl is a widely used herbicide to control Poaceae weeds. Alopecurus japonicus, a widespread annual grass, can no longer be controlled by haloxyfop-R-methyl after continuous use of this herbicide for several years. RESULTS: Dose-response experiments have established that the Js-R biotype of A. japonicas has evolved resistance to aryloxyphenoxypropionates (APPs). Target-site enzyme sensitivity experiments have established that the haloxyfop (free acid) rate causing 50% inhibition of acetyl-CoA carboxylase (ACCase) activity (I50) for the resistant (Js-R) biotype is 11 times higher than that for the susceptible (Js-S) biotype. In many cases, resistance to ACCase-inhibiting herbicides is due to a resistant ACCase enzyme. Full-length DNA and mRNA sequences of the plastidic ACCase gene were amplified. Eight single-nucleotide differences were detected in this region. Four of the nucleotide changes were silent mutations. However, the other four nucleotide mutations caused four amino acid substitutions, replacing Arg-1734 with Gly, Met-1738 with Leu, Thr-1739 with Ser and Ile-2041 with Asn in the R biotype respectively; the substitution at position 2041 had been reported, while the other three had not. CONCLUSION: The ACCase in the Js-R biotype was less susceptible to haloxyfop-R-methyl than that in the Js-S biotype. Moreover, the amino acid substitution of Ile-2041 with Asn might confer resistance to haloxyfop-R-methyl in A. japonicas.

• 出版日期2012-9
• 单位南京农业大学