Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The UV-B photoreceptor UVR8 promotes photosynthetic efficiency in Arabidopsis thaliana exposed to elevated levels of UV-B
AU - Davey, Matthew
AU - Susanti, Novata
AU - Wargent, Jason
AU - Findlay, Jane
AU - Quick, Paul
AU - Paul, Nigel
AU - Jenkins, Gareth
PY - 2012/12
Y1 - 2012/12
N2 - 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 (ΦPSII) 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/Fm 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.
AB - 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 (ΦPSII) 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/Fm 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.
KW - Arabidopsis
KW - ELIP
KW - PSII
KW - SIG5
KW - UV-B
KW - UVR8
KW - LIGHT-RESPONSIVE PROMOTER
KW - SIGNALING COMPONENT UVR8
KW - TRANSCRIPTION FACTOR HY5
KW - ULTRAVIOLET-B
KW - PHOTOSYSTEM-II
KW - GENE-EXPRESSION
KW - ACTION SPECTRUM
KW - HIGHER-PLANTS
KW - RADIATION
KW - STRESS
U2 - 10.1007/s11120-012-9785-y
DO - 10.1007/s11120-012-9785-y
M3 - Journal article
VL - 114
SP - 121
EP - 131
JO - Photosynthesis Research
JF - Photosynthesis Research
SN - 0166-8595
IS - 2
ER -