Tissue expression pattern and regulatory function of ERD15 in response to UV-B signaling in Arabidopsis thaliana

Ultraviolet B band (UV-B) radiation, as an important component of the solar radiation spectrum and a key environmental factor, can regulate the expression of numerous genes and thus affects plant growth and development. Previous studies have shown that EARLY RESPONSIVE TO DEHYDRATION 15 (ERD15), acting downstream of BBX24, is known to mediate UV-B-induced hypocotyl growth inhibition, its precise regulatory function and molecular mechanisms within UV-B signaling remain unclear. In this study, we explored the tissue-specific expression patterns and regulatory roles of ERD15 in UV-B responses at the phenotypic, physiological, and transcriptional levels, revealing the regulatory network of ERD15 involvement in UV-B signaling. GUS staining revealed that UV-B radiation significantly suppressed ERD15 expression in hypocotyls and leaves, without causing obvious changes in roots. Phenotypic and physiological assessment further demonstrated that ERD15 inhibited the enhancement of leaf photosynthetic capacity under UV-B radiation. Transcriptome analysis indicated that ERD15 modulates UV-B responses through MAPK kinase, phytohormone, and antioxidant pathways, and interacts with multiple transcription factor families. Collectively, these findings elucidated the roles of ERD15 within the UV-B signaling regulatory network, and improved the current understanding of its molecular mechanisms.