An isoleucine-leucine substitution in chloroplastic acetyl-CoA carboxylase from green foxtail (Setaria viridis L. Beauv.) is responsible for resistance to the cyclohexanedione herbicide sethoxydim

Planta. 2002 Jan;214(3):421-7. doi: 10.1007/s004250100633.


The cDNAs encoding chloroplastic acetyl-CoA carboxylase (ACCase, EC from three lines of Setaria viridis (L. Beauv.) resistant or sensitive to sethoxydim, and from one sethoxydim-sensitive line of Setaria italica (L. Beauv.) were cloned and sequenced. Sequence comparison revealed that a single isoleucine-leucine substitution discriminated ACCases from sensitive and resistant lines. Using near-isogenic lines of S. italica derived from interspecific hybridisation, we demonstrated that the transfer of the S. viridis mutant ACCase allele into a sethoxydim-sensitive S. italica line conferred resistance to this herbicide. We confirmed this result using allele-specific polymerase chain reaction and showed that a single copy of the mutant allele is sufficient to confer resistance to sethoxydim. We conclude that a mutant allele of chloroplastic ACCase encoding a leucine residue instead of an isoleucine residue at position 1780 is a major gene of resistance to sethoxydim.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyl-CoA Carboxylase / genetics*
  • Acetyl-CoA Carboxylase / metabolism
  • Alleles
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Chloroplasts / drug effects
  • Chloroplasts / enzymology*
  • Cyclohexanones / pharmacology*
  • Drug Resistance / genetics
  • Genes, Dominant
  • Herbicides / pharmacology*
  • Isoleucine / genetics
  • Leucine / genetics
  • Molecular Sequence Data
  • Phylogeny
  • Poaceae / drug effects
  • Poaceae / enzymology
  • Poaceae / genetics*
  • Point Mutation
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Cyclohexanones
  • Herbicides
  • Isoleucine
  • sethoxydim
  • Acetyl-CoA Carboxylase
  • Leucine

Associated data

  • GENBANK/AF294805