Abstract
The plant hormone jasmonic acid (JA) is known to have an important role as a signaling transducer in elicitor-inducible defense responses in rice. To date, it has been shown that a F-box protein COI1 functions in a central part of a JA signaling in some plants; however, in rice a molecular basis mechanism of the JA signaling remains unknown. In this report, we demonstrate that rice OsCOI1 homologs function in the JA signaling pathway by analyzing OsCOI1-reduced RNAi lines. In these lines, RERJ1, which is a JA-responsive bHLH transcription factor gene, was not induced its expression in response to exogenously applied JA. This result suggests that OsCOI1 plays an important role in JA signaling of rice defense responses. Expression profiles of other JA-responsive genes, phytoalexins production, and phenotypic observations in these OsCOI1 RNAi plants are under examination.
