Abstract
RIM1 of rice encodes a novel NAC transcription factor. We previously reported that RIM1 functions as a repressor of JA signaling and is degraded by proteasome in response to JA treatment. Recently, it was reported that Arabidopsis JAZ repressor proteins are direct targets of COI1, which is an F-box protein, and degraded by JA treatment. Arabidopsis COI1 is a single gene, while three orthologs of COI1 are found in rice genome. It's possible that rice COI1 orthologs may target other repressor proteins including RIM1. To test this possibility, we examined the interaction between the RIM1 and COI1. However, none of rice COI1 orthologs was interacted with RIM1 in yeast two-hybrid assay and in vivo pull-down assay. These results suggested RIM1 may not regulate the well-known signaling pathway through COI1, but may represent a new molecular link of JA signaling yet identified.
