Plant–Microbe–Metal (PMM) Interactions and Strategies for Remediating Metal Ions

Abstract

Sessility is a characteristic of plants. Hence, plants have evolved various mechanisms to interact with other organisms in the environment and to deal with biotic or abiotic stresses. One of the contributing factors of abiotic stress is metal ions in plants. Plants and microbes require certain metal ions to complete their life cycle, but all metal ions in excess are toxic. Plant microbiome comprises microbes from different kingdoms which have substantial effects on nutrient uptake, growth, and biotic and abiotic stress tolerance. At various bioavailable concentrations of metal ions, interactions between plant and microbes, generally known as plant–microbe–metal (PMM) interactions, are of interest due to their potential applications in higher crop productivity and metal remediation. Some of the PMM interactions are beneficial under metal stress which enhances uptake, trafficking, sequestration, and detoxification of toxic metal ions by microbe or plant or both the species. This chapter discusses metal homeostasis or metallostasis mechanisms in plants and microbes. Furthermore, the factors affecting PMM interactions, recent techniques for investigating the PMM interactions, metal toxicity and potential use of PMM interactions in metal remediation from the environment are thoroughly described.