Characterization of the NifA-RpoN Regulon in Rhizobium etli CFN42 in symbiosis using whole genome transcript analysis

The NifA-RpoN complex is a master regulator of the nitrogen fixation genes in alpha-proteobacteria. Based on the complete Rhizobium etli genome sequence, we constructed the R. etli CFN42 oligonucleotide (70 mer) microarray, and utilized this tool to survey changes in gene expression in R. etli CFN42 wild type compared with NifA CFNX247 mutant strain in symbiosis with Phaseolus vulgaris. As expected, the genes associated with a NifA and RpoN binding sites were downregulated in the NifA mutant strain. Three independent biological materials with one dyeswap were performed.