Recent advances in UVR8-mediated signal transduction

Ultraviolet-B (UV-B) radiation (280 nm-315 nm) is an essential component of sunlight that modulates various biological processes in plants. As the plant-specific UV-B photoreceptor, UV Resistance Locus 8 (UVR8) serves as the core molecule mediating UV-B signal perception and transduction in plants, playing a crucial role in regulating plant photomorphogenesis and stress adaptation. The canonical UVR8 pathway has been well characterized: upon UV-B perception, UVR8 undergoes dimer to monomer, accumulates in the nucleus, and then interacts with functional proteins to regulate gene transcription or other modification processes. However, recent studies have revealed non-canonical functions of UVR8, and its functions are not only evolutionarily conserved but also exhibit species-specific characteristics across different organisms. This review systematically summarizes recent progress in UVR8-mediated signal transduction, focusing on two core aspects: (1) the expanding spectrum of UVR8-interacting proteins and their functional roles; (2) evolutionary conservation and species-specific adaptations of UVR8 signaling. We also highlight unresolved key questions in UVR8 signal transduction, aiming to provide a reference for future mechanistic research and crop breeding applications.