农作物对Cd毒害的耐性机理探讨

Tolerance mechanism of crops to Cd pollution

对生长在Ｃｄ污染条件下的８种作物体内Ｃｄ的存在形态分析表明，作物的耐Ｃｄ性与Ｃｄ的形态分布密切相关，在耐性作物体内，蛋白质（多肽）结合Ｃｄ量的比例低于非耐性作物；有机酸盐和一代磷酸盐态Ｃｄ的比例增加；分离得到Ｃｄ诱导蛋白，其中束缚了一定量的Ｃｄ，限制了Ｃｄ以自由态存在．耐性较低的作物体内，大分子量的蛋白质中富Ｃｄ量较高．

Studies on Cd forms in 8 kinds of crops under Cd pollution show that the Cd tolerance ofcrops is closely related to the distribution of Cd forms. In Cd-tolerant crops, the percentage of Cd combined with protein (polypeptide) is higher, organic Cd and Cd hydrophos-phare are more, and Cd-induced protein contains definite amounts of bound Cd which limits the existence of free Cd. In crops with lower Cd tolerance, big molecular protein isrich in Cd.