Sub-cellular Fraction of Heavy Metals and Production of Phytochelatins in Zizania latifolia Exposed to Cadmium and Lead

A single-harvested cultivar, ‘Jiangshujiao’,and a double-harvested cultivar,‘Fenghongzao’,of Zizania latifolia were used as experimental materials to determine the content of non-protein-thiols(NPT),glutathione(GSH),and phytochelatins(PCs).To clarify the tolerance mechanism of Zizania latifolia to Cd²⁺ and Pb²⁺ stress,accumulation of Cd²⁺ and Pb²⁺ in subcellular fractions were also investigated.The results showed that content of NPT,GSH,and PCs and the accumulation of Cd²⁺ and Pb²⁺ in subcellular fractions increased significantly when treated with Cd²⁺ and Pb²⁺ stress.Content was higher when treated with combined stress than single stress.Content of NPT,GSH and PCs were significantly lower in leaves than in roots.The cell wall and the soluble fraction of cells had higher Cd²⁺ and Pb²⁺ accumulation levels than the protoplast and the organelles,respectively.