Gene expression profiles of a Si- norhizobium meliloti 1021 nifA mutant and wild type nodule bacteria were compared using whole genome microarrays. The results revealed a large scale al- teration of gene expression (6...Gene expression profiles of a Si- norhizobium meliloti 1021 nifA mutant and wild type nodule bacteria were compared using whole genome microarrays. The results revealed a large scale al- teration of gene expression (601 genes) in the nifA minus background. The loss of NifA altered the ex- pression of many functional groups of genes (mac- romolecular metabolism, TCA cycle and respiration, nodulation and nitrogen fixation) and may lead to quite different life stages of the nodule bacteria. Upregulation of fixK and its associated genes was observed in the nifA mutant nodule bacteria. Addi- tional quantitative real-time PCR experiments re- vealed that the transcript levels of fixLJ were signifi- cantly upshifted in the nifA mutant nodule bacteria. Putative NifA binding sites were predicted by a statis- tical method in the upstream sequences of 13 differ- entially regulated genes from the nifA- transcriptome.展开更多
基金This work was supported by the Chinese National Key Program for Basic Research （973） （Grant Nos. 001CB108901 ＆ 001CB108902）the National Natural Science Foundation of China （Grant No. 30470940）+1 种基金 Bundesministerium far Bildung und Forschung Germany （Grant No. 031U213D）Deutsche Forschungsgemeinschaft （Grant No. BIZ 7）.
文摘Gene expression profiles of a Si- norhizobium meliloti 1021 nifA mutant and wild type nodule bacteria were compared using whole genome microarrays. The results revealed a large scale al- teration of gene expression (601 genes) in the nifA minus background. The loss of NifA altered the ex- pression of many functional groups of genes (mac- romolecular metabolism, TCA cycle and respiration, nodulation and nitrogen fixation) and may lead to quite different life stages of the nodule bacteria. Upregulation of fixK and its associated genes was observed in the nifA mutant nodule bacteria. Addi- tional quantitative real-time PCR experiments re- vealed that the transcript levels of fixLJ were signifi- cantly upshifted in the nifA mutant nodule bacteria. Putative NifA binding sites were predicted by a statis- tical method in the upstream sequences of 13 differ- entially regulated genes from the nifA- transcriptome.
