Role of endophytes in plant tolerance to heavy metal stress

Abstract:

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.