The octadecanoid pathway is required for pathogen-induced multi-functional acetyl-CoA carboxylase accumulation in common bean (Phaseolus vulgaris L.)

A partial cDNA clone corresponding to the multi-functional acetyl-CoA carboxylase (ACCase, EC 6.4.1.2) was isolated using RNA extracted from methyl jasmonate (MeJA)-induced common bean cell cultures. Most of this clone corresponds to the 3' untranslated region and it showed high identity to alfalfa and soybean ACCase sequences. Southern hybridization revealed one copy of this gene in the common bean genome. In addition to being induced by MeJA in cell cultures and leaves, ACCase mRNA accumulated after yeast elicitor or Pseudomonas syringae pv tabaci treatment. Inhibitors of the octadecanoid pathway severely reduced ACCase mRNA and protein accumulation induced by yeast elicitor or P. syringae pv tabaci, indicating that jasmonates or a precursor mediate ACCase induction after pathogen infection. These results provide a role for the eukaryotic ACCase during the defense response to pathogens in common bean.