Relative expression level of <i>lao</i> gene in different strains determined by qRT-PCR [26].

<p>Rf-1: wild type; B1 and B19: two mutants of wild type Rf-1 with transposon-inserted <i>sdmT</i> gene and <i>nhaD</i> gene, respectively; B1/M and B19/M: both mutant B1 and mutant B19 with blank delivery vector pBBR1MCS-5; B1/MS and B19/MN: mutant B1 and mutant B19 with complementary plasmid pBBR1MCS-5/<i>sdmT</i> carrying entire gene of <i>sdmT</i> and plasmid pBBR1MCS-5/<i>nhaD</i> carrying entire gene <i>nhaD</i>, respectively. Mean difference of relative expression of <i>lao</i> gene between different strains was statistically analyzed by ANOVA (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122741#pone.0122741.s003" target="_blank">S3 Dataset</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122741#pone.0122741.s004" target="_blank">S4 Dataset</a>). “***” is extremely significant (P<0.001).</p>