期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2003
卷号:100
期号:15
页码:9061-9066
DOI:10.1073/pnas.1532302100
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:In plants and microorganisms, salt stress regulates the expression of large numbers of genes. However, the machinery that senses salt stress remains to be characterized. In this study we identified sensory histidine kinases that are involved in the perception of salt stress in the cyanobacterium Synechocystis sp. strain PCC 6803. A library of strains with mutations in all 43 histidine kinases was screened by DNA microarray analysis of genomewide gene expression under salt stress. The results suggested that four histidine kinases, namely, Hik16, Hik33, Hik34, and Hik41, perceived and transduced salt signals. However, Hik33, Hik34, and Hik16 acting with Hik41 regulated the expression of different sets of genes. These histidine kinases regulated the expression of {approx}20% of the salt-inducible genes, whereas the induction of the remaining salt-inducible genes was unaffected by mutations in any of the histidine kinases, suggesting that additional sensory mechanisms might operate in the perception of salt stress. We also used DNA microarrays to investigate the effect of various salts on gene expression. Our results indicate that Hik33 responds to sodium salts and not to KCl, whereas the Hik16/Hik41 system responds only to NaCl.