Genome-wide identification of the BES1 gene family and functional study of VcBES1.3 under salt stress in blueberry (Vaccinium corymbosum)

Abstract

BES1 (BRI1-EMS-SUPPRESSOR 1) transcription factors mediate brassinosteroid signaling and regulate plant growth, development, and stress responses. The BES1 family has not been characterized in blueberry ( Vaccinium corymbosum L.). We identified 16 VcBES1 family members and classified them into four groups based on phylogenetic analysis. Promoters of the BES1 genes mainly contain cis -elements associated with abiotic stress and phytohormone signaling. Tissue-specific expression analysis showed that the VcBES1 family is expressed predominantly in roots and stems. All members except VcBES1.8 and VcBES1.9 responded positively to salt stress. Among them, VcBES1.3 displayed the strongest salt induction. The protein accumulated in the nucleus. Overexpression and RNA interference (RNAi) experiments established that VcBES1.3 enhances salt tolerance. This study characterizes the VcBES1 family, defines its tissue-specific and stress-responsive expression patterns, and demonstrate that VcBES1.3 as a positive regulator of salt tolerance in blueberry.