Wheat and barley rhizospheres Raw sequence reads

Drought legacy effect on plant beneficial bacteria under contrasting farming conditionsDrought is critical for plant fitness and survival, especially when successive drought events happen. Some soil microorganisms are able to improve plant tolerance to stress, like microbes with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Some microorganisms adapted to dry conditions are selected by plants over time because of their physiological properties like sporulation, substrate preference or cell-wall thickness. However, the complexity and interconnection between abiotic factors, like drought or soil management, and biotic factors, like plant species identity, make it difficult to elucidate general microbial selection processes difficult to elucidate. Using a pot experiment with soils from conventional and organic farming agriculture plots with wheat or barley, a drought legacy effect on soil microorganisms was determined by comparing single and successively repeated drought events. The analysis of the total microbial community (16S rRNA genes) and the ACC deaminase positive microbial community showed that drought conditioning strongly impacts both communities. Plants under conventional farming showedhad a higher growth and were able to select microbial taxa known for their plant-beneficial properties. Our approach allowed us to identify key taxa for drought adaptation, and to improve our understanding of drought effects on plant-microbes interaction.