Identification of bZIP Gene Family in Bergenia purpurascens and Functional Characterization of BpbZIP37 Under Heat Stress.

Bergenia purpurascens, a perennial herb with significant medicinal value, thrives in harsh high-altitude environments but faces threats from global warming-induced heat stress. Basic leucine zipper (bZIP) transcription factors play crucial roles in plant growth, development, and stress responses, yet their functions in B. purpurascens remain unstudied. In this study, we identified 55 bZIP genes (BpbZIP1-55) from B. purpurascens transcriptome data. Expression pattern analyses identified several tissue-specific expressed BpbZIP genes, as well as eight heat stress-induced BpbZIP genes. Among them, BpbZIP37 was the most significantly induced by heat stress and was used for functional characterization via over-expression in Arabidopsis thaliana. The results indicated that BpbZIP37 can enhance the heat tolerance of plants by reducing reactive oxygen species accumulation and increasing activities of antioxidant enzymes. This study provides new insights into exploring the functions of bZIP genes in B. purpurascens, highlighting BpbZIP37 as an important regulator of heat stress responses, which lays a foundation for plant breeding improvement and resource conservation tailored to climate change.