Rice Wrky13Transcriptionally Regulates The Crosstalk Between Abiotic-and Biotic-stress Signalings By Selectively Binding To Different Cis-eiements

Rice WRKY13plays a vital role in the crosstalk of abiotic-and biotic-stress signaling pathways by suppressing abiotic-stress tolerance and activating disease resistance. However, it is not clear whether WRKY13is a transcriptional activator or a repressor and which genes are direct transcriptional targets of WRKY13in this crosstalk. Here, we show that WRKY13is a transcriptional repressor. It preferentially binds to certain site-and sequence-specific W-like boxes and a non-W and non-W-like box element PRE4other than typical W box. WRKY13selectively bound to different cis-elements on the promoters of SNAC1, the positive regulator of abiotic stress tolerance, and WRKY45-1, the negative regulator of both disease resistance and abiotic stress tolerance during rice response to drought stress and bacterial infection. WRKY13was rapidly induced by bacterial infection and drought stress in guard cells where transcriptional factor SNAC1mediates drought tolerance via promoting stomatal closure. WRKY13also binding to one cis-element of its native promoter to autoregulate the balance of its gene expression in different physiological activities and to another cis-element of its native promoter to feedback activate its gene expression in rice-bacterium interaction. These results suggest that WRKY13appears to transcriptionally regulate drought tolerance and disease resistance by binding to site-and sequence-specific cis-elements of SNAC1, WRKY45-1, and WRKY13promoters in specific tissues or cells.