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

Matthew P. Davey, Novita I. Susanti, Jason J. Wargent, Jane E. Findlay, W. Paul Quick, Nigel D. Paul, Gareth I. Jenkins

Research output: Contribution to journalArticle

32 Citations (Scopus)

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 (Fv/Fm) 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 Fv/-Rffrt m and ΦPSII 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.

Original languageEnglish
Pages (from-to)121-131
Number of pages11
JournalPhotosynthesis Research
Volume114
Issue number2
Early online date19 Nov 2012
DOIs
Publication statusPublished - 1 Dec 2012

Keywords

  • Arabidopsis
  • ELIP
  • PSII
  • SIG5
  • UV-B
  • UVR8

Fingerprint Dive into the research topics of 'The UV-B photoreceptor UVR8 promotes photosynthetic efficiency in Arabidopsis thaliana exposed to elevated levels of UV-B'. Together they form a unique fingerprint.

  • Cite this