The Role Of Rnase ? In Oxidative Stress Response In Synechocystis Sp.PCC 6803

Double-stranded RNA plays important roles in gene regulation.As a typical enzyme which processes the double-stranded RNA,RNase ? has been investigated mainly in a few bacteria like Escherichia coli and Bacillus subtilis.Synechocystis sp.PCC 6803 is one of the important model strains for basic researches,including photosynthesis,carbon and nitrogen balance,and cellular adaptions to various stress conditions.Synechocystis sp.PCC 6803 confers three genes encoding RNase III family proteins:slr0346,slr1646 and slr0954.We have already constructed the mutant strains successfully,and found that the slr0346 mutant(?slr0346)showed impaired growth in the presence of methyl viologen.Based on that,we first tested the sensitivity of ?slr0346,?slr1646 and ?slr0954 on the stresses of methyl viologen,hydrogen peroxide and ferric chloride.We found that ?slr0346 was exceptionally sensitive to methyl viologen.Therefore we further explored the change of transcription profiles of Synechocystis sp.PCC 6803 and ?slr0346 after methyl viologen treatment by RNA-seq.According to the physiological experiment results and RNA-seq data,we obtained the following conclusions:1)Synechocystis sp.PCC 6803 adapts to the oxidative stress by methyl violet through reshaping many physiological processes,including expressing of antioxidant enzymes,enhancing the transportation system,modulating DNA,RNA and protein synthesis,improving the energy metabolism,etc;2)Gene slr0346 is essential for Synechocystis sp.PCC 6803 to response the oxidative stress by methyl violet;3)RNase? prefers to cleave the mRNA of genes that included in transport,translation,energy metabolism and sugar metabolism when Synechocystis sp.PCC 6803 is in oxidative stress.Our work about the role of RNase III in Synechocystis sp.PCC 6803 to response the oxidative stress would be much of help for further illustrating the mechanism of oxidative stress adaptation and cellular functions of RNase III in cyanobacteria.