超积累植物与丛枝菌根真菌共生及其联合吸收积累重金属的效应

Symbiosis between hyperaccumulators and arbuscular mycorrhizal fungi and their synergistic effect on the absorption and accumulation of heavy metals: a review

摘要:

利用超积累植物进行重金属污染土壤修复是应对全球大面积分布无机污染问题的重要解决方法之一。超积累植物虽然具有超量积累重金属的能力，但其定植、生长和提取功能的发挥都受到重金属胁迫的显著影响。利用丛枝菌根真菌 (Arbuscular mycorrhizal fungi，AMF) 强化超积累植物功能可联合发挥二者的功能优势，提升修复效率、缩短修复周期、保持修复效果的稳定性和长期性，在日益复杂、严峻的重金属污染治理领域具有重要的研究价值和广阔的应用前景。文中首先给出了超积累植物的概念、中国本土首次报道的典型重金属元素超积累植物和能与AMF形成共生体系的超积累植物名录，系统深入地探讨了AMF对超积累植物生长和吸收累积重金属的影响，以及超积累植物+AMF联合吸收积累重金属的效应与作用机制，认为AMF可通过调节根围理化与生物条件、元素平衡状况、生理代谢和基因表达等途径，增强超积累植物吸收积累重金属的效应，超积累植物+AMF构建的共生体系具备联合修复重金属污染生境的潜力。最后指出了超积累植物+AMF共生联合修复技术当前面临的关键问题、发展方向和应用前景。

Abstract:

The remediation of heavy-metal (HM) contaminated soil using hyperaccumulators is one of the important solutions to address the inorganic contamination widely occurred worldwide. Hyperaccumulators are able to hyperaccumulate HMs, but their planting, growth, and extraction capacities are greatly affected by HM stress. The application of arbuscular mycorrhizal fungi (AMF) enhances the function of hyperaccumulators by combining the functional advantages of both, improving the efficiency of remediation, shortening the remediation cycle, and maintaining the stability and persistence of the remediation. Thus, the combined use of AMF with hyperaccumulators has broad prospects for application in the management of increasingly complex and severe HM pollution. This review starts by defining the concept of hyperaccumulators, followed by describing the typical hyperaccumulators that were firstly reported in China as well as those known to form symbioses with AMF. This review provides a systematic and in-depth discussion of the effects of AMF on the growth of hyperaccumulators, as well as the absorption and accumulation of HMs, the effects and mechanism on the hyperaccumulator plus AMF symbiosis to absorb and accumulate HMs. AMF enhances the function of hyperaccumulators on the absorption and accumulation of HMs by regulating the physicochemical and biological conditions in the plant rhizosphere, the situation of elements homeostasis, the physiological metabolism and gene expression. Moreover, the symbiotic systems established by hyperaccumulators plus AMF have the potential to combine their abilities to remediate HMs-contaminated habitat. Finally, challenges for the combined use of remediation technologies for hyperaccumulator plus AMF symbiosis and future directions were prospected.