Microbial diversity in the rhizosphere of plants growing under extreme environments and its impact on crop improvement

Abstract

Abiotic stresses have adverse efects on the plant growth and productivity. Over the last decades, scientists have been intrigued by the fascinating microorganisms that exist in the rhizosphere of plants growing under extreme environments. Members of bacterial phyla Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes and archaeal phyla Euryarchaeota and Crenarchaeota are found to be more abundant in the rhizosphere of plants growing in extreme environments. Rhizosphere microbiomes enhance plant growth under abiotic stresses by nitrogen fxation, phytohormones production, mineral solubilization, siderophores and HCN production and eliciting plant defense mechanisms against diferent bacterial and fungal pathogens. Meta-omics techniques such as metagenomics, metatranscriptomics and metaproteomics can also be used to study complex processes involved in microbe-mediated stress alleviation in diferent plants growing in extreme environments. These approaches generate multi-layered information that can lead to massive outcomes; hence, there are more chances for implementation in this feld. This review summarizes the information about the archaeal and bacterial diversity living in the root microbiome of plants growing under extreme conditions. We also described diferent mechanisms about role of plant growth promoting microorganisms under abiotic stresses and highlighted the applications of meta-omics approaches to explain further advancement in plant–microbe interactions.