traG Gene Is Conserved across Mesorhizobium spp. Able to Nodulate the Same Host Plant and Expressed in Response to Root Exudates

Figure 6

Analysis of traG and nodA gene expression by semiquantitative RT-PCR in M. mediterraneum UPM-Ca3 and M. ciceri LMS-1 strains. These genes expression level were evaluated in bacteria (1; no exudates) nonexposed to Cicer arietinum exudates (2; exudates) exposed to Cicer arietinum root exudates and in bacteroids within nodules collected (3; nodules 15 dpi) 15 days after inoculation and (4; nodules 21 dpi) bacteroids within nodules of plants collected 21 days after inoculation. (a) M. mediterraneum UPM-Ca3 traG expression. (b) M. mediterraneum UPM-Ca3 nodA gene expression. (c) M. ciceri LMS-1 traG expression. (d) M. ciceri LMS-1 nodA expression. Relative abundance of traG and nodA transcripts was normalized against 16S rRNA gene expression. Data are presented as the mean and standard deviation values of three independent biological replicates. Different letters (A, B) correspond to statistical significant differences (P < 0.05).

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