An aspartate to glycine change in the carboxyl transferase domain of acetyl CoA carboxylase and non-target-site mechanism(s) confer resistance to ACCase inhibitor herbicides in a Lolium multiflorum population

Pest Manag Sci. 2010 Nov;66(11):1249-56. doi: 10.1002/ps.2003.

Abstract

Background: The increasing use of ACCase-inhibiting herbicides has resulted in evolved resistance in key grass weeds infesting cereal cropping systems worldwide. Here, a thorough and systematic approach is proposed to elucidate the basis of resistance to three ACCase herbicides in a Lolium multiflorum Lam. (Italian rye grass) population from the United Kingdom (UK24).

Results: Resistance to sethoxydim and pinoxaden was always associated with a dominant D2078G (Alopecurus myosuroides Huds. equivalent) target-site mutation in UK24. Conversely, whole-plant herbicide assays on predetermined ACCase genotypes showed very high levels of resistance to diclofop-methyl for all three wild DD2078 and mutant DG2078 and GG2078 ACCase genotypes from the mixed resistant population UK24. This indicates the presence of other diclofop-methyl-specific resistance mechanism(s) yet to be determined in this population. The D2078G mutation could be detected using an unambiguous DNA-based dCAPS procedure that proved very transferable to A. myosuroides, Avena fatua L., Setaria viridis (L.) Beauv. and Phalaris minor Retz.

Conclusion: This study provides further understanding of the molecular basis of resistance to ACCase inhibitor herbicides in a Lolium population and a widely applicable PCR-based method for monitoring the D2078G target-site resistance mutation in five major grass weed species.

MeSH terms

  • Acetyl-CoA Carboxylase / antagonists & inhibitors
  • Acetyl-CoA Carboxylase / chemistry*
  • Acetyl-CoA Carboxylase / genetics
  • Amino Acid Substitution
  • Enzyme Inhibitors / pharmacology*
  • Herbicide Resistance / genetics*
  • Herbicides / pharmacology*
  • Lolium / drug effects*
  • Lolium / enzymology
  • Lolium / genetics
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Sequence Analysis, DNA

Substances

  • Enzyme Inhibitors
  • Herbicides
  • Acetyl-CoA Carboxylase