ZmDREB1A controls plant immunity via regulating salicylic acid metabolism in maize.

DREB1A, a pivotal transcription factor, has long been known to regulate plant abiotic stress tolerance. However, its role in plant biotic stress tolerance and the underlying mechanisms have remained a mystery. Our research reveals that the maize ZmDREB1A gene is up-regulated in maize seedlings when the plants are infected by Rhizoctonia solani (R. solani). The maize ZmDREB1A knock-out mutant exhibits increased disease resistance against the pathogen R. solani. Further investigation showed that ZmDREB1A regulates salicylic acid (SA) metabolism by inhibiting ZmSARD1 gene and activating ZmSAGT gene expression. Additionally, the SA level was increased while the SAG level was decreased in zmdreb1a mutant seedlings when the plants were infected with the pathogen R. solani. Furthermore, overexpression of ZmSAGT in Arabidopsis reduced plant resistance to Pst DC3000 by decreasing SA levels and increasing SAG levels. These data demonstrate that ZmDREB1A regulates the metabolism of SA and controls plant immune response in maize.