LAUSR

Background and aimsCereus jamacaru is a native cactus in the semiarid biome caatinga able to withstand long periods of drought. Here, we studied the rhizosphere microbiome of this cactus to understand how precipitation affects the assembly of bacterial communities from the taxonomical and functional perspectives.MethodsWe selected three C. jamacaru plants in the caatinga biome, sampled the rhizosphere soil from the same plants during rainy and dry seasons and performed shotgun sequencing from total DNA isolated from rhizosphere using Ion Torrent technology.ResultsAcidobacteria, Actinobacteria and Proteobacteria showed increase in relative abundance during the rainy season when compared to dry season. Five major functional groups were significantly different, including differences in amino acids and derivatives, carbohydrates, protein metabolism, respiration, and RNA metabolism. Taxonomically, the assembly of bacterial communities follows a neutral model.ConclusionsThe assembly of bacterial communities in the rhizosphere of C. jamacaru is affected by precipitation resulting in different taxonomical and functional community patterns during dry and rainy seasons. We attribute these differences on rhizosphere communities composition to dispersal limitation of microorganisms caused by low pore connectivity due to low water content in the soil, which leads to spatially isolate communities during the dry season.