根系分泌物与重金属的化学行为研究

通过毛细管电泳测定根系分泌物的组成发现,根系在受到重金属铅、镉或铅-镉共同作用下分泌物种类与对照都有不同程度的变化;透析袋平衡透析方法则证实了根系分泌物与重金属之间存在着络合反应,络合能力的大小与重金属本身的性质有关,小麦根系分泌物对铅的络合能力大于镉。溶解试验表明,小麦分泌物对红壤中铅、镉的溶出没有显著的影响。小麦无菌根系分泌物、非无菌分泌物、非无菌过0.45m分泌物均促进红壤对铅、镉的吸附。其中铅吸附量较对照分别增加了12%,16%,21%;镉吸附量较对照分别增加了66%,102%,72%。

Study on chemical behavior of root exudates with heavy metals

In the present work, we studied the interaction between root exudates and heavy metals using wheat and rice exudates produced from sterile and non-s t erile hydroponic conditions. Capillary electrophoretic analysis showed the consi derable differences in composition of root exudate from wheat and rice as stress ed under Pb, Cd. equilibrium dialysis showed that root exudates bound metals to an extent that depended on the metal involved. As for wheat exudates, the import ance of the binding followed the order Pb > Cd. Moreover, we also studied their metal-solubilizing ability for both Cd and Pb. It showed that the solubility of Pb and Cd were not affected by root exudates of wheat. The result also showed th at adsorption in red soil increased 12%, 16%, 21% with Pb and 66%, 102%, 72% wit h Cd in the presence of sterile exudates, non-sterile exudates, non-sterile an d filtrated throngh 0.45μm film, respectively.