title: Biochemical and Molecular Mechanisms of Plant-Microbe-Metal Interactions: Relevance for Phytoremediation.
abstract: Plants and microbes coexist or compete for survival and their cohesive interactions play a vital role in adapting to metalliferous environments, and can thus be explored to improve microbe-assisted phytoremediation. Plant root exudates are useful nutrient and energy sources for soil microorganisms, with whom they establish intricate communication systems. Some beneficial bacteria and fungi, acting as plant growth promoting microorganisms (PGPMs), may alleviate metal phytotoxicity and stimulate plant growth indirectly via the induction of defense mechanisms against phytopathogens, and/or directly through the solubilization of mineral nutrients (nitrogen, phosphate, potassium, iron, etc.), production of plant growth promoting substances (e.g., phytohormones), and secretion of specific enzymes (e.g., 1-aminocyclopropane-1-carboxylate deaminase). PGPM can also change metal bioavailability in soil through various mechanisms such as acidification, precipitation, chelation, complexation, and redox reactions. This review presents the recent advances and applications made hitherto in understanding the biochemical and molecular mechanisms of plant-microbe interactions and their role in the major processes involved in phytoremediation, such as heavy metal detoxification, mobilization, immobilization, transformation, transport, and distribution.
authors.affiliation: Centre for Functional Ecology, Department of Life Sciences, University of Coimbra Coimbra, Portugal.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Centre for Functional Ecology, Department of Life Sciences, University of CoimbraCoimbra, Portugal; Department of Environmental Health, Research Centre on Health and Environment, School of Allied Health Sciences, Polytechnic Institute of PortoVila Nova de Gaia, Portugal; Centro de Biotecnologia e Química Fina, Escola Superior de Biotecnologia, Universidade Católica PortuguesaPorto, Portugal.
authors.forename: Rui S
authors.initials: RS
authors.lastname: Oliveira
authors.affiliation: Centre for Functional Ecology, Department of Life Sciences, University of Coimbra Coimbra, Portugal.
authors.forename: Helena
authors.initials: H
authors.lastname: Freitas
authors.affiliation: Chuzhou University Chuzhou, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhang
keywords: heavy metals; molecular bases; phytoremediation; plant growth promoting microorganisms; root exudates