Aims Phytoremediation of soil contaminated by trace elements is a technology using plants and microorganisms to sequester, inactivate, or extract contaminants from the soil. The assemblage formed by the partnership between plants and microorganisms is referred to as the plant holobiont concept. Among holobiont microorganisms, endophytes are associated with the plant at its earliest growth stage and are localized inside plant tissues. While plant tissues shelter endophytic microbial communities, mutualistic endophytes have shown a potential for plant growth promotion that will deeply and durably benefit the plant holobiont. In this review, we describe the state-of-the-art knowledge of the endophytes’ role in plant growth promotion and the prospects for phytoremediation technologies. Results Mutualistic symbionts have been demonstrated to improve plant growth, germination and yield. Indeed, they improve plant nutrition, increase plant resistance to bio-aggressors and stimulate plant metabolite productions. Research has shown that endophytes improve plant performance especially under extreme conditions such as drought, nitrogen deficiency, salinity and exposition to metal phytotoxicity. Endophyte inoculation has shown potential for plant growth promotion and has increased metal translocation in hyperaccumulator shoots by mitigating stresses from contaminated and naturally metal-rich soils. Conclusions Endophytes have demonstrated their potential to enhance the plant’s physiological status under metallic stress, the growth of both roots and shoots, as well as increasing metal uptake in the shoot biomass of a wide diversity of hyperaccumulating plants. Endophyte-assisted phytoremediation is a promising technology for the remediation of polluted or naturally metal-rich soils.

中文翻译：

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内生菌是植物必不可少的伙伴吗？金属植物修复的前景如何？

目标 微量元素污染土壤的植物修复是一种利用植物和微生物从土壤中隔离、灭活或提取污染物的技术。由植物和微生物之间的伙伴关系形成的组合被称为植物全生物概念。在全生物微生物中，内生菌在植物的最早生长阶段与植物相关联，并且位于植物组织内。虽然植物组织为内生微生物群落提供庇护，但共生内生菌已显示出促进植物生长的潜力，这将深刻而持久地有益于植物全息生物。在这篇综述中，我们描述了内生菌在植物生长促进中的作用的最新知识以及植物修复技术的前景。结果 互惠共生体已被证明可以改善植物生长、发芽和产量。事实上，它们可以改善植物营养，增加植物对生物侵略者的抵抗力并刺激植物代谢产物的产生。研究表明，内生菌可改善植物性能，尤其是在干旱、缺氮、盐度和暴露于金属植物毒性等极端条件下。内生菌接种已显示出促进植物生长的潜力，并通过减轻来自受污染和天然富含金属的土壤的压力来增加超富集植物枝条中的金属易位。结论 内生菌已显示出它们在金属胁迫下增强植物生理状态、根和芽的生长、以及增加各种超积累植物的枝条生物量中的金属吸收。内生菌辅助植物修复是一种很有前景的技术，可用于修复受污染或天然富含金属的土壤。