根系分泌物在重金属污染土壤生态修复中的作用机制研究进展

我国土壤重金属污染问题日益突出。作为一种绿色、安全的生物修复技术，植物修复技术备受关注。根系分泌物作为植物-土壤-微生物三者物质交换与信息传递的重要载体，是植物响应外界胁迫的重要生理生态指征，在植物修复过程中发挥关键作用。研究表明，根系分泌物能够有效调控根际微环境，提升植物抗逆能力，影响重金属在根际微域中的环境行为。传统的根际生态研究更多聚焦在养分调控等方面，而关于根系分泌物在污染场地生态修复中的作用机制研究相对较少。本文综述了根系分泌物对土壤理化性质、土壤微生物、植物生理代谢过程以及重金属在土壤-植物系统中迁移转化等方面的影响，系统总结了植物根系分泌物响应重金属胁迫的生理生态机制，并对未来土壤重金属污染生态修复研究方向进行了展望。

Research progress on root exudates and their effects on ecological remediation of heavy metal contaminated soil

Heavy metal contamination has become a serious environmental issue in China. Phytoremediation, as a green and safe bioremediation technology, has attracted much attention to researchers. Root exudates play an important role in nutrient cycling and signal transduction among plant-soil-microorganism interaction, as well as in the responses of plants to environmental stress during phytoremediation. Root exudates could regulate rhizosphere microenvironment, enhance plant tolerance, and affect the environmental behaviors of heavy metals in rhizosphere soils. Previous studies on rhizosphere ecology have focused more on nutrient regulation, but less on the effects of root exudates on phytoremediation of contaminated sites. We reviewed the effects of root exudations on soil physical and chemical properties, soil microorganisms, plant physiological metabolism, and mobilization of heavy metals in the soil-plant system. We systematically summarized the physiological and ecological responses of root exudates to heavy metal contamination, and pointed out promising direction and aspects for further studies.