The genistein stimulon of Bradyrhizobium japonicum.
An initializing step in the rhizobia-legume symbiosis is the secretion of flavonoids by plants that leads to the expression of nodulation genes in rhizobia. Here we report the genome-wide transcriptional response of Bradyrhizobium japonicum to genistein, an isoflavone secreted by soybean. About 100 genes were induced in the wild type. This included all nod box-associated genes, the flagellar cluster and several genes that are likely to be involved in transport processes. To elucidate the role of known regulators, we analysed mutant strains. This revealed that the two-component response regulator NodW is essential for induction of almost all genistein-inducible genes, with the exception of 8 genes. The phenotype of the nodW mutant could be partially suppressed by overexpression of NwsB, which is also a two-component response regulator. These data indicate that genistein has a much broader function than mere induction of nod genes.
Lang
Kathrin
K
Institute of Genetics, Dresden University of Technology, Helmholtzstrasse 10, 01069, Dresden, Germany.
Lindemann
Andrea
A
Hauser
Felix
F
Göttfert
Michael
M
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D020369:Bradyrhizobium / Q000187:drug effects* / Q000235:genetics*; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D005798:Genes, Bacterial / Q000187:drug effects*; D019833:Genistein / Q000494:pharmacology*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D012329:RNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D013025:Glycine max / Q000382:microbiology; D013559:Symbiosis / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; C063550:NodW protein, Bradyrhizobium japonicum; D012329:RNA, Bacterial; D014157:Transcription Factors; D019833:Genistein