Abstract
Jasmonates are plant hormones, which have crucial roles in developmental processes and defense responses against wounding stress and pathogens. COI1 mediates jasmonate signaling by promoting hormone-dependent ubiquitylation and degradation of transcriptional repressor JAZ proteins. The JAZ proteins are the repressors of MYC2, a JA responsive transcription factor. After the degradation of JAZs by SCFCOI1, MYC2 is released and regulates the expression of jasmonate-responsive genes.
Apart from MYC2, other transcriptional factors that interact with the JAZ proteins are still unknown. Based on our co-expression analysis, we focused on a bHLH transcription factor and designated as INU1. Yeast two hybrid analyses revealed that INU1 and its closest homolog interact with a few JAZ proteins. We also observed phenotypes of double, triple and quadruple mutants including myc2, inu1, and inu1 homologs. According to these results, we will discuss about the function of INU1.
