植物对重金属的吸收和分布

植物修复是利用植物来清除污染土壤中重金属的一项技术。该技术成功与否取决于植 物从土壤中吸取金属以及向地上部运输金属的能力。植物对金属的吸收主要取决于自由态离子活度。许多螯合剂能诱导植物对重金属的吸收。金属离子在液泡中的区域化分布是植物耐 重金属的主要原因。同时，细胞内的金属硫蛋白、植物螯合肽等蛋白质以及有机酸、氨基酸等在金属贮存和解毒方面也起重要作用。本文还论述了重金属在植物体内运输的生理及分子 方面的研究进展。

The Mechanisms of Heavy Metal Uptake and Accumulation in Plants

Phytoremediation is a technology that involves the use of plants to remove heavy metals from contaminated soil. This approach is based on the ability of plants to absorb contaminants from the soil and translocate them to their shoots. Plant uptake of a metal depends primarily on the free metal ion activity. However, some synthetic chelates have been shown to induce the uptake of metals by plants. Vacuolar compartmentalization appears to be the source of tolerance of metal-accumulating plants. In cells, proteins such as metallothioneins and phytochelatins, organic acids and amino acids also play an important role in metal ion storage and detoxification. Physiological and molecular aspects of heavy metal transport in plants are also discussed in this paper.