Figure 7.

Accumulation of PC2 upon exposure to Cd²⁺ and Zn²⁺. Wild-type Col-0, cad1-3, and cad1-6 were grown hydroponically in one-tenth-strength Hoagland medium for 5 weeks before either 0.5 μm Cd²⁺ or 20 μm Zn²⁺ were added to the medium. No extra metal ions were added to control plants. After 5 d roots and leaves were harvested, frozen in liquid N₂, and lyophyllized. Monobromobimane-derivatized extracts were analyzed by CapLC-ESI-QTOF-MS. Quantification of PC2 in wild-type Col-0 (black columns), cad1-3 (dark gray columns), and cad1-6 (light gray columns) is shown for control plants and those challenged with either Cd²⁺ or excess Zn²⁺. d.w., Dry weight.