PRJNA553176
Bacterial diversity of Agave lechugilla rizosphere in Cuatro Cienegas Basin
Due to the environmental conditions presented in arid zones, it is expected to have a high influence of deterministic processes over the community assemblages. Plants living in this habitats are well adapted to survive this difficult conditions but independently of their physiologic and morphological adaptations, the symbiotic interactions with microorganisms could be strengthen, facilitating colonization and survival. In this context, the microbial communities associated to plants that inhabit these types of areas can be a good model to understand the community assembly processes. In this study, we investigated the influence of deterministic and stochastic processes in the assemblage of rhizosphere microbial communities of Agave lechuguilla and bulk soil on the Cuatro Cienegas Valley, a site known for its oligotrophic conditions. We proposed two hypotheses: 1) Microbial co-occurrence patterns in Agave lechuguilla rhizosphere are distinct from those in bulk soil, which is affected by both abiotic and biotic factors (season and physicochemical properties of soil and plant interactions, respectively); 2) The keystone microbial species are usually critical for plant growth and health in the rhizosphere, whereas in the bulk soil they are related to the resistance to abiotic stress. In order to confirm this hypothesis, 16S rRNA gene was sequenced by Illumina from rhizospheric and bulk soil samples in two seasons, also the physicochemical properties of the soil were determined. Our results showed differences in bacterial diversity, community composition, potential functions and interaction networks between the rhizosphere samples and the ones from the bulk soil. Despite patterns of community structure depend on a complex balance between deterministic and stochastic forces acting on populations at different spatial scales and within different functional groups, our results suggest that Agave lechuguilla selects a specific microbial community inhabiting the rhizosphere based on functional traits, which may be related to benefits to the plant, as growth promotion and nutrition.