UVR8: A UV-B photoreceptor

Regulation of Plant Growth by Ultraviolet Rays

 Shipra Singh

Ultraviolet-B radiation (UV-B) is an intrinsic part of sunlight, which is a potential abiotic stress factor for any organism. However, low-level, non-damaging UV-B serves as a photomorphogenic signal to regulate various biological effects in plants including inhibition of hypocotyl growth, flavonoid biosynthesis, entrainment of the circadian clock, phototropism, stress tolerance, auxin signaling and many more. A unique molecular signaling pathway exists for UV-B acclimation and perception via a UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8). Significant progress has been made in understanding the molecular events in UVR8-mediated signaling and responses. Among these are two recent reports elucidating the constitutive interaction of UVR8 with different transcription factors including WRKY DNA-BINDING PROTEIN 36 (WRKY36), BRI1-EMS-SUPPRESSOR 1 (BES1) and BES1-INTERACTING MYC- LIK1 (BIM1).

Suggested readings:

1. Yin, R., and Ulm, R. (2017). How plants cope with UV-B: from perception to response. Curr. Opin. Plant Biol. 37, 42–48.
2. Yang, Y., Liang, T., Zhang, L., Shao, K., Gu, X., Shang, R., Shi, N., Li, X., Zhang, P., and Liu, H. (2018). UVR8 interacts with WRKY36 to regulate HY5 transcription and hypocotyl elongation in Arabidopsis. Nat Plants 4, 98–107.
3. Liang, T. et al. (2018) UVR8 interacts with BES1 and BIM1 to regulate transcription and photomorphogenesis in Arabidopsis. Dev. Cell 44, 1–12