Action spectrum of psbA gene transcription is similar to that of photoinhibition in Synechocystis sp. PCC 6803.
The photosystem II (PSII) reaction center protein D1 undergoes rapid light-dependent turnover, which is caused by photoinhibition. To identify the photoreceptor(s) involved in the light-dependent expression of the psbA gene encoding the D1 protein, we determined the action spectra of psbA transcription, PSII activity, photosynthesis and photoinhibition in Synechocystis sp. PCC 6803. In accordance with its phycobilisome antenna, PSII showed the highest activity in the spectral region from yellow to red and only low activity in the ultraviolet-A (UV-A) to green region. Photoinhibition, in turn, was fastest in UV-A to violet light and a minor peak was found in the orange region. The action spectrum of psbA transcription resembled closely that of photoinhibition, suggesting that photoinhibition creates a signal for up-regulation of the psbA gene.
Tyystjärvi
Taina
T
Plant Physiology and Molecular Biology, University of Turku, FIN-20014, Turku, Finland. taityy@utu.fi
Tuominen
Ilona
I
Herranen
Mirkka
M
Aro
Eva-Mari
EM
Tyystjärvi
Esa
E
D000458:Cyanobacteria / Q000235:genetics* / Q000528:radiation effects*; D005798:Genes, Bacterial / Q000528:radiation effects; D008565:Membrane Proteins / Q000235:genetics* / Q000528:radiation effects*; D018462:Photobiology; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics* / Q000528:radiation effects*; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000528:radiation effects; D014466:Ultraviolet Rays
D008565:Membrane Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes; C089909:photosystem I, psaB subunit