title: Disruption of nifA gene influences multiple cellular processes in Sinorhizobium meliloti.
abstract: Sinorhizobium meliloti nifA is important in fixing nitrogen during symbiosis. A nifA null mutant induces small white invalid nodules in the roots of host plant. The additional phenotypic alterations associated with the disruption of the nifA gene are reported in this study. Under a free-living state, S. meliloti nifA mutant reduces its ability to swarm on a half-solid plate. Interestingly, the AHL (Acylhomoserine lactones) contents in the nifA mutant are lower than that of the wild type during the lag phase, whereas it is reversed in the logarithmic and stationary phases. Quantitative spectrophotometric assays reveal that the total amount of extracellular proteins of the nifA mutant are lower than that of the wild type. In addition, the mutant abolishes its nodulation competitive ability during symbiosis. These findings indicate that NifA plays a regulatory role in multiple cellular processes in S. meliloti.
authors: National Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors: Ziying
authors: Z
authors: Gong
authors: Jiabi
authors: J
authors: Zhu
authors: Guanqiao
authors: G
authors: Yu
authors: Huasong
authors: H
authors: Zou
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D000332:Aerobiosis / Q000235:genetics; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001522:Behavior, Animal; D005110:Extracellular Space / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics*; D009068:Movement; D009154:Mutation; D010641:Phenotype; D016962:Sinorhizobium meliloti / Q000166:cytology* / Q000235:genetics* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; C061338:NifA protein, Bacteria; D014157:Transcription Factors