Microbiome of Halophytes: Diversity and Importance for Plant Health and Productivity

Abstract

The distribution of saline soils on more than half a billion hectare worldwide warrants attention for their efficient, economical and environmentally acceptable management practices. Halophytes are progressively utilized for human benefits. Halophytes microbiome contributes significantly to plant performance and can provide information regarding complex ecological processes involved in osmoregulation of halophytes. Microbial communities associated with the rhizosphere, phyllosphere and endosphere of halophytes play an important role in plant health and productivity. Members of plant microbiome belonging to domains Archaea, Bacteria and kingdom Fungi are known to be involved in osmoregulation of halophytes. Mostly halophilic microorganisms use compatible solutes such as glycine betaine, proline, trehalose, ectoine and glutamic acid to survive under salinity stress conditions. Plant growth promoting rhizobacteria (PGPR) enhance plant growth and help to elucidate the salinity tolerance. The detailed studies on metabolic pathways of plants have shown that PGPRs contribute to plant tolerance by affecting the signaling network of plants. Phytohormones (indole-3-acetic acid and cytokinin), 1-aminocyclopropane-1-carboxylic acid deaminase (ACC) biosynthesis, exopolysaccharides, halocins and volatile organic compounds function as signaling molecules for plants to elicit salinity stress. This review has mainly focused on the functions of plant microbiome and how these microorganisms impact on halophyte health and growth.