Figure 1.

Complementation by HvZIP cdnas of the yeast mutant Δzrt1Δzrt2 defective in Zn²⁺ uptake at pH 4.2 and pH 5.5. Yeast cells transformed with the empty vector pFL6.1 or with a pFL6.1 construct containing either HvZIP3, HvZIP5, HvZIP8 or HvIRTI were spotted on Sd medium as described elsewhere (Pedas et al., 2009) with either 50 mm succinic acid/Tris base pH 4.2 or 5.5 with reduced content of free Zn controlled by EGTA. The Δzrt1Δzrt2 yeast strain showed a strong phenotype and therefore an additional supply of 0.2 mm ZnSO₄ was necessary for obtaining control growth. Plates were incubated for three to five days at 30°C.