重金属胁迫下内生菌对宿主植物的解毒机制

Role of endophytes in plant tolerance to heavy metal stress

采用内生菌联合植物修复是土壤重金属污染修复理论研究和应用实践的新思路。较之根际促生菌,内生菌因生存环境稳定且与植物联系更加紧密,在实际应用中具有更大价值。在重金属胁迫下,部分具有特定功能的细菌可进入植物体内成为内生菌,这些内生菌通常在重金属吸收、耐受和解毒方面具有优良的特性,而且可以协同宿主植物耐受重金属胁迫,表现在直接或间接降低植物体内重金属胁迫强度和提高植物本身对重金属的耐受性两方面。系统分析了内生菌对宿主植物的解毒机制,综述了近年来内生菌增强植物重金属耐受性的研究,展望了重金属胁迫下植物和内生菌互作机制的研究思路和方向。

Phytoremediation coupled with plant growth-promoting endophytes （PGPEs） is becoming a new trend in remediation of heavy metal contaminated soil. Compared with rhizobacteria, PGPEs have a more stable living environment and show more intimate relations with host plants, which play a greater value in practical application. Under heavy metal stress, a portion of bacteria could enter plant tissue and become endophytes, which possess superior characteristics in heavy metal accumulation, tolerance and detoxification, coordinating with the heavy metal tolerance system of their host plants. The performances of PGPEs appear in reducing the heavy metal stress intensity in plants directly or indirectly and promoting the heavy metal tolerance system of plants through modulating phenotypes. The role of PGPEs in plant heavy metal detoxification was analyzed systematically and the relevant researches in recent years were reviewed. In addition, the possible ways and research directions were proposed in the interaction mechanisms between PGPEs and plants under heavy metal stress.