Figure 2

Metal regulated transcriptional activation of BjMTP1 by its 983 bp promoter. Five-day-old dark grown seedlings, transformed with p (1.0) BjMTP1::GUSPlus, were exposed to different concentrations of Ni²⁺ (A), Cd²⁺ (B) or Zn²⁺ (C) and both GUS activity (nmol MU/mg protein/min) and K⁺ leakage (nmoles K⁺/min/mg dry weight) measured. Each data point represents an average (± SD) of three independent replicate samples. (D) Histochemical GUS staining of seedlings exposed to 25 μM Ni²⁺ for 48 h (bottom) and unexposed seedlings (top). Insert shows the GUS localization in an individual seedling. Scale bar = 1 cm.