The bZIP transcription factor GmbZIP15 facilitates resistance against Sclerotinia sclerotiorum and Phytophthora sojae infection in soybean

Abstract

Soybean, one of the most valuable oilseed crops, is under constant pressure from pathogens. bZIP transcription factors (TFs) composing one of the largest TF families in plants have diverse functions. Biochemical and physiological analyses were performed to characterize the regulatory roles of soybean bZIP TF GmbZIP15 in response to pathogens. We found that transgenic soybean plants overexpressing <i>GmbZIP15</i> has increased resistance against <i>Sclerotinia sclerotiorum</i> and <i>Phytophthora sojae</i>. Besides, <i>GmbZIP15</i> regulates pathogen response by modulating the antioxidant defense system and phytohormone signaling. In addition, we performed chromatin immunoprecipitation sequencing to identify the downstream genes of <i>GmbZIP15</i> in response to <i>S</i>. <i>sclerotiorum</i> and found that <i>GmbZIP15</i> can activate or repress the expression of defense-related genes through direct promoter binding. Taken together, these results indicate that <i>GmbZIP15</i> plays a positive role in pathogen resistance in soybean, and this activity may be dependent on phytohormone signaling.