由于重金属污染日益严重，重金属在土壤-植物系统中的行为引起了人们的高度重视。高等植物对重金属的耐性与积累性，已经成为污染生态学研究的热点。近年来，由于分子生态学等学科的发展，有关植物对重金属的解毒和耐性机理、重金属离子富集机制的研究取得了较大进展。高等植物对重金属的耐性和积累在种间和基因型之间存在很大差异。根系是重金属等土壤污染物进入植物的门户。根系分泌物改变重金属的生物有效性和毒性，并在植物吸收重金属的过程中发挥重要作用。土壤中的大部分重金属离子都是通过金属转运蛋白进入根细胞，并在植物体内进一步转运至液泡贮存。在重金属胁迫条件下植物螯合肽（PC）的合成是植物对胁迫的一种适应性反应。耐性基因型合成较多的PC，谷胱甘肽（GSH）是合成PC的前体，重金属与PC螯合并转移至液泡中贮存，从而达到解毒效果。金属硫蛋白（MTs）与PC一样，可以与重金属离子螯合，从而降低重金属离子的毒性。该文从分子水平上论述了根系分泌物、金属转运蛋白、MTs、PC、GSH在重金属耐性及超积累性中的作用，评述了近10年来这方面的研究进展，并在此基础上提出存在的问题和今后研究的重点。
Owing to serious heavy metal pollution, much attention has been paid to its effects on soil-plant systems. The research of heavy metal tolerance and hyperaccumulation of higher plants has become a hot topic in the field of pollution ecology. With the development of molecular ecology, research on the mechanisms of heavy metal tolerance, detoxification and accumulation in higher plants has made progress in recent years. There are significant differences in the tolerance to and accumulation of heavy metals among higher plant species and genotypes. Root systems are the first entrance of heavy metal pollutants from the soil into plant. Root exudates reduce the availability and toxicity of metal pollutants and play an important role in ability for plants to absorb heavy metals. Almost all heavy metal ions enter root cells with the help of a metal transporter protein that are subsequently transported to the vacuole. The synthesis of PC in response to the stress caused by heavy metals is one of the adaptive responses common in higher plants. Heavy metal tolerant genotypes have higher levels of PC than non-tolerant genotypes under heavy metal stress. GSH is the substrate that synthesizes PC, which chelates the heavy metals. Heavy metal-PC chelatins are subsequently transported from the cytosol to the vacuole and heavy metal detoxification is thus achieved. MTs play the same role and in the same way as PC under heavy metal stress. The article reviews recent advances in understanding the role of root exudates, metal transporter proteins (MTs, PC and GSH), molecular mechanisms of heavy metal tolerance and hyperaccumulation in higher plants at the molecular level. Existing problems and major topics of future research were discussed.