The role of abiotic factors modulating the plant-microbe-soil interactions: toward sustainable agriculture. A review

Microbial soil communities are active players in the biogeochemical cycles, impacting soil fertility and interacting with aboveground organisms. Although soil microbial diversity has been studied in good detail, the factors that modulate its structure are still relatively unclear, especially the environmental factors. Several abiotic elements may play a key role in modulating the diversity of soil microbes, including those inhabiting the rhizosphere (known as the rhizosphere microbiome). This review summarizes relevant and recent studies that have investigated the abiotic factors at different scales, such as pH, temperature, soil type, and geographic and climatic conditions, that modulate the bulk soil and rhizosphere microbiome, as well as their indirect effects on plant health and development. The plant-microbiome interactions and potential benefits of plant growth-promoting rhizobacteria are also discussed. In the last part of this review, we highlight the impact of climate change on soil microorganisms via global temperature changes and increases in ultraviolet radiation and CO2 production. Finally, we propose the need to understand the function of soil and rhizospheric ecosystems in greater detail, in order to effectively manipulate or engineer the rhizosphere microbiome to improve plant growth in agricultural production.