The potential role of plant-associated bacteria to improve the efficiency of phytoremediation of metal-contaminated soils using rapeseed

Abstract

Worldwide, metal-contaminated soils pose a serious threat to environmental health. High metal concentrations are toxic to most organisms. From soil, metals can leach into the groundwater or accumulate in plants and thus in multiple food chains. The remediation of metal-contaminated soils is urgent. Vast areas with diffuse metal contamination cannot be remediated using conventional techniques (e.g. excavation). In this work, we focus on the natural ability of plants and their associated microorganisms to remove trace elements from soils by concentrating them in the harvestable plant parts (i.e. phytoextraction). The main constraints limiting full-scale application of this technique using economically attractive high-biomass accumulator plants are low metal availability in the soil and low metal uptake, translocation, accumulation and tolerance of plants. It is known that plant-associated bacteria with metal-mobilizing and plant growth-promoting properties and a natural capacity to cope with trace elements can be exploited to increase plant biomass and metal tolerance on the one hand and metal uptake on the other hand. The enrichment of such bacteria in high-biomass accumulator plant species might result in a more efficient phytoextraction of trace elements. ...