Ultraviolet-B light (UV-B) is an inherent part of sunlight, which has significant biological effects on plants. Low level, non-damaging UV-B serves as a photomorphogenic signal to regulate photomorphogenesis. UVR8 (UV RESISTANCE LOCUS 8) is a UV-B photoreceptor that mediates light responses in plant. The mechanism by which UVR8 triggers UV-B photomophogenic responses in the nucleus and whether or not UVR8 interacts with transcription factors to directly regulate transcription is still unknown.

A group led by Dr Hongtao Liu from CAS Center for Excellence in Molecular Plant Sciences/Shanghai Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Science (CAS) provides evidence that UVR8 interacts with WRKY36 to regulate photomorphogeneis in response to UV-B light.

Their results demonstrate that Arabidopsis WRKY36 physically interacts with UVR8 in vivo, and the UVR8-WRKY36 complex accumulates in nuclei in response to photomorphogenic UV-B light stimulus. WRKY36 promotes hypocotyl elongation by repressing the transcription of HY5, and WRKY36 is involved in UV-B responses downstream of UVR8, UV-B activated and nucleus localized UVR8 repress the DNA binding activity of WRKY36. These results demonstrate that UVR8 can regulate gene expression in response to UV-B light by directly interacting with the transcription factor WRKY36. WRKY36 is a novel UVR8 interacting protein and the UVR8-WRKY36-HY5 is a novel UV-B signaling pathway.

This work entitled “UVR8 interacts with WRKY36 to regulate HY5 transcription and hypocotyl elongation in Arabidopsis” has been published online in Nature Plants on January 29th. The research was funded by MOST, NSFC and CAS.

CONTACT:
Dr. Hongtao Liu, PhD, Professor
National Key Laboratory of Plant Molecular Genetics
CAS Center for Excellence in Molecular Plant Sciences
Institute of Plant Physiology and Ecology (SIPPE)
Chinese Academy of science (CAS)
+86-21-54924291
Email: htliu@sibs.ac.cn