植物内生细菌在植物修复重金属污染土壤中的应用

Applications of endophytic bacteria in phytoremediation of heavy metals-contaminated soils

土壤重金属污染是威胁人群健康和经济可持续发展的重要环境问题。植物修复具有经济、环保等特点,已成为治理重金属污染土壤的重要技术。如何提高植物对重金属的抗性、促进植物生长是影响植物修复效率的关键之一。内生菌群-植物共生关系在此方面具有独特优势。其中,植物内生细菌可改善植物营养、降低植物病菌感染、影响酶活性,以及分泌激素、含铁载体和有机配位体等,进而提高超积累植物对重金属的吸收作用。本文综述了近年来国内外关于抗重金属植物内生细菌筛选与应用的研究进展,分析了内生细菌促进植物生长、增强植物对重金属抗性、促进重金属向茎叶转移的机理,阐述了植物内生细菌在重金属污染土壤修复中的应用前景与研究重点。

Soil heavy metals contamination has become a worldwide environmental problem,posing great threats to human health and economic development. At present,phytoremediation is recognized as the most cost-effective and reliable remediation technique for heavy metals-contaminated soils. This technique mainly utilizes hyper-accumulator plants to extract and accumulate the contaminants from soil. How to improve the heavy metals resistance of plants and promote the plant growth dominates the phytoremediation efficiency. In this aspect,plant-endophytic bacteria symbiosis has its unique superiority. Endophytic bacteria have positive effects on the plant establishment and survival in heavy metals-contaminated soils via improving plant nutrient uptake,decreasing plant pathogens infection,affecting plant enzyme activities,secreting hormone,siderophores,and other organics,and as a consequence,enhancing the heavy metals accumulation by plants. This paper reviewed the recent studies on the screening and application of heavy metals-resistant endophytic bacteria,elucidated the mechanisms of endophytic bacteria-promoted plant growth,plant heavy metals resistance,and heavy metals translocation from root to shoot,and analyzed the processes and mechanisms of endophytic bacteria-enhanced phytoremediation. The potential applications of endophytic bacteria in phytoremediation of heavy metals-contaminated soils were proposed.