OsWRKY114 Negatively Regulates Drought Tolerance by Restricting Stomatal Closure in Rice

Abstract

The WRKY family of transcription factors plays a pivotal role in plant responses to biotic and abiotic stress. The WRKY Group III transcription factor OsWRKY114 is a positive regulator of innate immunity against <i>Xanthomonas oryzae</i> pv. <i>oryzae</i>; however, its role in abiotic stress responses is largely unknown. In this study, we showed that the abundant <i>OsWRKY114</i> transcripts present in transgenic rice plants are reduced under drought conditions. The overexpression of <i>OsWRKY114</i> significantly increased drought sensitivity in rice, which resulted in a lower survival rate after drought stress. Moreover, we showed that stomatal closure, which is a strategy to save water under drought, is restricted in <i>OsWRKY114</i>-overexpressing plants compared with wild-type plants. The expression levels of <i>PYR/PYL/RCAR</i> genes, such as <i>OsPYL2</i> and <i>OsPYL10</i> that confer drought tolerance through stomatal closure, were also markedly lower in the <i>OsWRKY114</i>-overexpressing plants. Taken together, these results suggest that OsWRKY114 negatively regulates plant tolerance to drought stress via inhibition of stomatal closure, which would otherwise prevent water loss in rice.