In this study,cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profi les of the transcriptomes of Synechocystis sp.PCC6803 under low temperature(LT)stress.Among the genes on the cDNA microarrays,899 LT-affected genes exhibited a 1.5-fold(or greater)difference in expression compared with the genes from normal unstressed Synechocystis sp.PCC6803.Of the differentially expressed genes,353 were up-regulated and 246 were down-regulated.The results showed that genes involved in photosynthesis were activated at LT(10°C),including genes for photosystem I,photosystem II,photosynthetic electron transport,and cytochrome b6/f complex.Moreover,desB,one of four genes that encode the fatty acid desaturases,was also induced by LT.However,the LT conditions to some degree enhanced the transcription of some genes.In addition,LT(10°C)may reduce cellular motility by regulating the transcription of spkA(sll1575),a serine/threonine protein kinase.The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT,including pathways involved in photosynthesis and repair.
