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

Abstract

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 plantmicrobiome 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 CO 2 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.Additional key words: abiotic interactions; plant growth-promoting rhizobacteria; rhizosphere microbiome; soil.Correspondence should be addressed to Gustavo Santoyo: gsantoyo@umich.mx

Diversity and plant growth-promoting functions of diazotrophic/N-scavenging bacteria isolated from the soils and rhizospheres of two species of Solanum

“…The modulation of the microbial community of plant holobionts is not stable over time because different biotic and abiotic conditions normally occur throughout the plant life cycle, and these variations may produce greater impacts than the genomic content on the qualitative and quantitative composition of rhizodeposits [14,15]. Other biotic and abiotic factors, such as the native soil microbial diversity, physical and chemical soil properties and geographic and climatic conditions, also play important roles in shaping the composition and function of rhizosphere microbiomes [16,17].…”

Efficient colonization of the endophytes Herbaspirillum huttiense RCA24 and Enterobacter cloacae RCA25 influences the physiological parameters of Oryza sativa L. cv. Baldo rice

“…The area of BNF research has been expanded by the discovery of N-fixing bacterial endophytes in non-nodulating plants. Bacterial endophytes promote plant growth through nitrogen fixation, phytohormone production, nutrient acquisition and by conferring tolerance to abiotic and biotic stresses (Haney et al, 2015;Berg et al, 2016;Yuan et al, 2016;Santoyo et al, 2017). They most often inhabit the plant intercellular spaces, which are abundant in carbohydrates, amino acids and inorganic nutrients (Compant et al, 2011;Liu et al, 2017).…”

Soil protist diversity in the Swiss western Alps is better predicted by topo-climatic than by edaphic variables

“…Nevertheless, a enhanced drainage reduces the likelihood of water-logging which would select for very specialized protists tolerating anoxia and generally would lead to lower diversity. Soil pH is well known as a major driver of microbial diversity, including bacteria (Santoyo, Hernandez-Pacheco, Hernandez-Salmeron, & Hernandez-Leon, 2017; Yashiro et al, 2016), fungi (Noyce et al, 2016; Pellissier et al, 2014; Zhang, Jia, & Yu, 2016) and protists (Bates et al, 2013; Dupont et al, 2016). The relationship between pH and protist diversity was significant only for three groups, being negative for two groups of phagotrophs (Spirotrichea and Sarcomonadida) and positive for Chlorophyceae.…”