The UV-B photoreceptor UVR8 promotes photosynthetic efficiency in Arabidopsis thaliana exposed to elevated levels of UV-B

Davey, M.P., Susanti, N.I., Wargent, J.J., Findlay, J.E., Quick, W.P., Paul, N.D. and Jenkins, G.I. (2012) The UV-B photoreceptor UVR8 promotes photosynthetic efficiency in Arabidopsis thaliana exposed to elevated levels of UV-B. Photosynthesis Research, 114(2), pp. 121-131. (doi:10.1007/s11120-012-9785-y)

Full text not currently available from Enlighten.

Abstract

The UV-B photoreceptor UVR8 regulates expression of genes in response to UV-B, some encoding chloroplast proteins, but the importance of UVR8 in maintaining photosynthetic competence is unknown. The maximum quantum yield of PSII (F v/F m) and the operating efficiency of PSII (Φ PSII) were measured in wild-type and uvr8 mutant Arabidopsis thaliana. The importance of specific UVR8-regulated genes in maintaining photosynthetic competence was examined using mutants. Both F v/F m and Φ PSII decreased when plants were exposed to elevated UV-B, in general more so in uvr8 mutant plants than wild-type. UV-B increased the level of psbD-BLRP (blue light responsive promoter) transcripts, encoding the PSII D2 protein. This increase was mediated by the UVR8-regulated chloroplast RNA polymerase sigma factor SIG5, but SIG5 was not required to maintain photosynthetic efficiency at elevated UV-B. Levels of the D1 protein of PSII decreased markedly when plants were exposed to elevated UV-B, but there was no significant difference between wild-type and uvr8 under conditions where the mutant showed increased photoinhibition. The results show that UVR8 promotes photosynthetic efficiency at elevated levels of UV-B. Loss of the DI polypeptide is probably important in causing photoinhibition, but does not entirely explain the reduced photosynthetic efficiency of the uvr8 mutant compared to wild-type.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Findlay, Mrs Jane and Jenkins, Professor Gareth
Authors: Davey, M.P., Susanti, N.I., Wargent, J.J., Findlay, J.E., Quick, W.P., Paul, N.D., and Jenkins, G.I.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Photosynthesis Research
Publisher:Springer
ISSN:0166-8595
Published Online:19 November 2012

University Staff: Request a correction | Enlighten Editors: Update this record