Identification of RAV transcription factors (B3-domain-containing) and functional analysis of OsRAV2 in rice blast and drought stress.

RAV transcription factors play roles in a variety of diverse biological processes. However, their role in rice's response to drought and blast stress remains largely unexplored. In this study, we performed a genome-wide characterization and identification of rice RAV transcription factor family genes. Our analysis of gene structure, chromosome location, cis-regulatory elements, and collinearity revealed the phylogenetic characteristics of this gene family. The RT-qPCR of the 15 genes showed that the expression levels of OsRAV2 were up-regulated under the two stress treatments. The overexpression of OsRAV2 enhanced drought resistance through the regulation of Pro, MDA and HO levels, and the transcription levels of ABA signaling pathway genes. Additionally, the overexpression of OsRAV2 enhanced rice resistance to blast disease by increasing the accumulation of Pro and HO, along with the expression of disease resistance-related genes. OsRAV2 is localized in the nucleus and interacts with OsLHCB5. This study reveals the positive role of OsRAV2 in enhancing drought and blast resistance of rice, and nuclear localization and interaction with OsLHCB5 revealed that OsRAV2 responds to stress by integrating light signals, which provides a new target for breeding rice varieties with broad-spectrum stress resistance.