Regulation of Arabidopsis gene expression by low fluence rate UV-B independently of UVR8 and stress signaling

O'Hara, A., Headland, L. R. , Díaz-Ramos, L. A., Morales, L. O., Strid, Å. and Jenkins, G. I. (2019) Regulation of Arabidopsis gene expression by low fluence rate UV-B independently of UVR8 and stress signaling. Photochemical and Photobiological Sciences, 18(7), pp. 1675-1684. (doi: 10.1039/C9PP00151D) (PMID:31218318)

Abstract

UV-B exposure of plants regulates expression of numerous genes concerned with various responses. Sudden exposure of non-acclimated plants to high fluence rate, short wavelength UV-B induces expression via stress-related signaling pathways that are not specific to the UV-B stimulus, whereas low fluence rates of UV-B can regulate expression via the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8). However, there is little information about whether non-stressful, low fluence rate UV-B treatments can activate gene expression independently of UVR8. Here, transcriptomic analysis of wild-type and uvr8 mutant Arabidopsis exposed to low fluence rate UV-B showed that numerous genes were regulated independently of UVR8. Moreover, nearly all of these genes were distinct to those induced by stress treatments. A small number of genes were expressed at all UV-B fluence rates employed and may be concerned with activation of eustress responses that facilitate acclimation to changing conditions. Expression of the gene encoding the transcription factor ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN 13 (ANAC13) was studied to characterise a low fluence rate, UVR8-independent response. ANAC13 is induced by as little as 0.1 μmol m−2 s−1 UV-B and its regulation is independent of components of the canonical UVR8 signaling pathway COP1 and HY5/HYH. Furthermore, UV-B induced expression of ANAC13 is independent of the photoreceptors CRY1, CRY2, PHOT1 and PHOT2 and phytochromes A, B, D and E. ANAC13 expression is induced over a range of UV-B wavelengths at low doses, with maximum response at 310 nm. This study provides a basis for further investigation of UVR8 and stress independent, low fluence rate UV-B signaling pathway(s).

• Item Type: Articles
• Additional Information: AO and LRH were supported by UK Biotechnology and Biological Sciences research council PhD studentships at the University of Glasgow. GIJ thanks the University of Glasgow for the support of his research. ÅS was supported by grants from the Knowledge Foundation (kks.se; contract no. 20130164) and The Swedish Research Council Formas (formas.se/en; Contract no. 942- 2015-516). ÅS and AO were also supported by the Faculty for Business, Science, and Technology at Örebro University, and LOM was supported by the Strategic Young Researchers Recruitment Programme at Örebro University.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jenkins, Professor Gareth and Diaz Ramos, Lourdes and Headland, Dr Lauren
• Authors: O'Hara, A., Headland, L. R., Díaz-Ramos, L. A., Morales, L. O., Strid, Å., and Jenkins, G. I.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Photochemical and Photobiological Sciences
• Publisher: Royal Society of Chemistry
• ISSN: 1474-905X
• ISSN (Online): 1474-9092
• Published Online: 20 June 2019
• Copyright Holders: Copyright © 2019 Royal Society of Chemistry and Owner Societies
• First Published: First published in Photochemical and Photobiological Sciences 18(7): 1675-1684
• Publisher Policy: Reproduced under a Creative Commons License