Perspectives of plant growth-promoting actinomycetes in heavy metal phytoremediation

Abstract

Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water, and air. In recent years, heavy metal phytoremediation assisted by plant beneficial actinomycetes has been highly used for cleaning up metal-polluted soils since these bacteria play an essential role in plant growth, metal/nutrient acquisition, metal detoxification, and alleviation of biotic/abiotic stress in plants. Direct plant growth promotion by actinomycetes is based on hormonal stimulation and improved nutrient acquisition by plants. Similarly, diverse mechanisms, viz., soil acidification and production of metal mobilizing/immobilizing substances by actinomycetes, are involved in heavy metal uptake by plants, which is often directly connected with the efficiency of phytoremediation process. Based on these beneficial plant-actinomycetes interactions, it is possible to develop microbial inoculants as environmentally friendly bio-tool for use in heavy metal phytoremediation. In this study, we highlight the diversity and plant growth beneficial features of actinomycetes and discuss their potential role on plant growth and phytoremediation process in metal-polluted soils.