Plant–microbiome interactions and their role in recovering ecosystems from persistent contaminants

Microorganisms, in particular prokaryotic cells, thanks to their small dimensions, wide metabolic abilities and fast reproduction, adapt continuously to environmental changes. Bacteria and Archaea are ubiquitous and develop promptly resistance to toxic effects of contaminants and capability of removing them through aerobic and anaerobic pathways. They can be used for bioremediation purposes both in bulk soil and in rhizosphere. The rhizosphere is a microhabitat, comprising roots and few millimeter soil/sediment immediately surrounding them, where an intense chemical dialog between plants and microorganisms occurs. Plants and microorganisms can interact so closely, which they can be considered as a metaorganism. Synergic interactions between plant and the microbiome improve the ecosystem’s homeostatic response to a number of disturbances and enable effective purification of soil and water, and removal of contaminants. This chapter describes some examples of nature-based solutions (e.g. Plant assisted-bioremediation, constructed wetlands and Plant-microbial fuel cells) that rely on plant and microorganisms as a unique metaorganism.