Figure 6.

Transient expression assays in bean leaf discs for Cd tolerance. PvERF15 overexpression (OE), PvERF15 RNAi (RNAi), and 35S:GUS (Control) bean leaf discs were generated by A. tumefaciens-mediated plant transformation. A, Histochemical staining in the 35S:GUS leaf discs but not in untransformed control to monitor the validity of transformation. At least six leaf discs were examined, and a typical disc is presented. Bar = 2.5 mm. B, PvERF15 accumulation levels in overexpression and RNAi plants relative to the control (set as 1) determined by qRT-PCR analysis. C and D, Phenotype (C) and chlorophyll content (D) from overexpression, RNAi, and control bean leaf discs treated with 200 μm CdCl₂ (+Cd) or without (−Cd) for 48 h. Chlorophyll content (μg per leaf disc) is given as means ± sd of three independent experiments (at least 30 leaf discs were analyzed for each transgenic line in an experiment). Significance between experimental values was assessed using Student’s t test, and P values are provided.