Genome-Wide Characterization of the TaPR10/Bet v 1 Family Reveals Their Evolutionary Features and Hormone-Responsive Expression in Wheat

Wheat is a globally important staple crop, whose growth and yield formation rely on the precise regulation of phytohormone signaling. The PR10/Bet v 1 (Pathogenesis-related protein 10/Betula verrucosa 1) family consists of conserved small-molecule ligand-binding proteins that participate in phytohormone signaling and plant development; however, systematic investigations of this family in wheat remain limited. Here, we performed a genome-wide identification of 75 PR10/Bet v 1 members in wheat, which were phylogenetically classified into three subfamilies: 21 known members belonging to the PYL (Pyrabactin resistance 1-like) subfamily, and 54 members assigned to two previously uncharacterized subfamilies. Bioinformatic analyses revealed that whole-genome/segmental duplication has driven the expansion of this gene family, which has evolved under strong purifying selection. Expression profiling and promoter analysis revealed differential expression patterns, along with abundant cis-acting elements responsive to multiple hormones. Quantitative RT-PCR (qRT-PCR) of 12 representative genes revealed marked transcriptional changes in several members within 1 h of treatment with BR (Brassinosteroid), ABA (Abscisic acid), CK (Cytokinin), or SA (Salicylic acid) suggesting that these genes may be directly involved in hormone-regulated processes. This study provides a fundamental framework for exploring the regulatory functions of the wheat PR10/Bet v 1 family, and valuable hormone-responsive candidate genes for the genetic improvement of wheat agronomic traits.