Abstract
Cyanobacteria modify their photosynthetic apparatus to mitigate their oxidative stress under high-light condition. Sll1961, a putative transcription factor involved in the response to high-light, was previously identified. The sll1961 mutant could not regulate photosystem stoichiometry under high-light condition. Although Sll1961 have a certain homology with a transcriptional regulator, the actual role of Sll1961 in the process of high-light acclimation is totally unknown. We picked up some candidates for its targets through the microarray analysis of the sll1961 mutant. The level of transcripts of slr0364, slr0366, and slr2057 were reduced in the sll1961 mutant. The differences in photosystem stoichiometry of the mutants of those genes from that of the wild type were less than that of the sll1961 mutant but some of the differences were significant. It implies that Sll1961 is involved in the modulation of photosystem stoichiometry through the transcriptional regulation of several genes during the acclimation to high-light.
