Abstract
Jasmonates are lipid derived signaling molecules. Several stress conditions cause endogenous accumulation of jasmonates, and then plants activate jasmonates signalling. COI1-dependent degradation of transcriptional repressor proteins such as JAZs was a key step for the activation of JA-dependent gene expression. It was reported that MYC2, which is a jasmonate-responsive transcriptional factor, was a target of JAZs. After the degradation of JAZs, the released MYC2 regulates the expression of jasmonates-responsive genes. To identify new transcriptional regulators in jasmonates signaling, we did cluster analysis of jasmonates-responsive genes. We focused on a bHLH transcriptional factor and named it INU1. To analyze the INU1 function in Arabidopsis, we obtained a T-DNA insertion line (inu1-1). GeneChip analysis showed that flavonoid biosynthetic pathway was activated and the expression of PDF1.2 was not induced in MeJA-treated inu1-1. These were contrasting phenotypes of MYC2 knockout mutants. We will discuss about the phenotypes of myc2inu1 double mutants.
