Signal transduction mediated by the plant UV-B photoreceptor UVR8

Ultraviolet-B (UV-B) light is an intrinsic part of sunlight that has significant effects on plant development and acclimation responses. UVR8 (UV Resistance Locus 8) is the long sought-after UV-B photoreceptor that mediates UV-B light perception and signal transduction. UV-B irradiation induces the monomerization and nuclear accumulation of UVR8 in plant cells to activate the UV-B signaling pathway. The photoactivated UVR8 could transduce UV-B signal via multiple mechanisms to regulate transcription and plant growth. Here, we summarize current understanding of UVR8-mediated UV-B signal transduction pathways, including UVR8-COP1 (CONSTITUTIVELY PHOTOMORPHOGENIC 1) and UVR8-WRKY36 (WRKY DNA-BINDING PROTEIN 36), UVR8-BES1 (BRI1-EMS-SUPPRESSOR1) and BIM1 (BES1-INTERACTING MYC-LIKE 1).