FIG 4.
Characterization of arsR gene expression in wild-type A. tumefaciens strain 5A. (A) Expression of arsR1, arsR2, and arsR4 was monitored using lacZ transcriptional fusions. Data are examples from reproducible experiments and represent the means for duplicate cultures, with error bars illustrating the data ranges. (B) Expression of the 16S rRNA and arsR3 genes as monitored using qualitative RT-PCR with an induction period as shown for panel A. Gel images were obtained for separate gels. In all cases for both panels, cultures were incubated with 200 μM Pi, with (+) or without (−) 100 μM As(III).