UV-B detected by the UVR8 photoreceptor antagonizes auxin signaling and plant shade avoidance

Hayes, S., Velanis, C. N., Jenkins, G. I. and Franklin, K. A. (2014) UV-B detected by the UVR8 photoreceptor antagonizes auxin signaling and plant shade avoidance. Proceedings of the National Academy of Sciences of the United States of America, 111(32), pp. 11894-11899. (doi: 10.1073/pnas.1403052111)

Abstract

Plants detect different facets of their radiation environment via specific photoreceptors to modulate growth and development. UV-B is perceived by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). The molecular mechanisms linking UVR8 activation to plant growth are not fully understood, however. When grown in close proximity to neighboring vegetation, shade-intolerant plants initiate dramatic stem elongation to overtop competitors. Here we show that UV-B, detected by UVR8, provides an unambiguous sunlight signal that inhibits shade avoidance responses in Arabidopsis thaliana by antagonizing the phytohormones auxin and gibberellin. UV-B triggers degradation of the transcription factors PHYTOCHROME INTERACTING FACTOR 4 and PHYTOCHROME INTERACTING FACTOR 5 and stabilizes growth-repressing DELLA proteins, inhibiting auxin biosynthesis via a dual mechanism. Our findings show that UVR8 signaling is closely integrated with other photoreceptor pathways to regulate auxin signaling and plant growth in sunlight.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jenkins, Professor Gareth
• Authors: Hayes, S., Velanis, C. N., Jenkins, G. I., and Franklin, K. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Proceedings of the National Academy of Sciences of the United States of America
• Publisher: National Academy of Sciences
• ISSN: 0027-8424
• ISSN (Online): 1091-6490