Cadmium induces acidosis in maize root cells.

* Cadmium (Cd) stress increases cell metabolic demand for sulfur, reducing equivalents, and carbon skeletons, to sustain phytochelatin biosynthesis for Cd detoxification. In this condition the induction of potentially acidifying anaplerotic metabolism in root tissues may be expected. For these reasons the effects of Cd accumulation on anaplerotic metabolism, glycolysis, and cell pH control mechanisms were investigated in maize (Zea mays) roots.

Heavy metal stress and sulfate uptake in maize roots.

ZmST1;1, a putative high-affinity sulfate transporter gene expressed in maize (Zea mays) roots, was functionally characterized and its expression patterns were analyzed in roots of plants exposed to different heavy metals (Cd, Zn, and Cu) interfering with thiol metabolism. The ZmST1;1 cDNA was expressed in the yeast (Saccharomyces cerevisiae) sulfate transporter mutant CP154-7A. Kinetic analysis of sulfate uptake isotherm, determined on complemented yeast cells, revealed that ZmST1;1 has a high affinity for sulfate (Km value of 14.