Effects of salt and drought stresses on rhizosphere soil bacterial community structure and peanut yield

Abstract

A pot experiment with Huayu 25 as experimental material was conducted, with treatments of drought and salt stresses. The effects of drought and salt stresses at the flowering stage on the plant morphology, pod yield, and soil bacterial community structure in the rhizosphere were examined. The results showed that Proteobacteria, Actinobacteria, Saccharibacteria, Chloroflexi, Cyanobacteria, and Acidobacteria were the dominant phyla in the rhizosphere soil of peanut. Compared with that under normal conditions, the relative abundance of Proteobacteria and Actinobacteria dramatically decreased, while that of Cyanobacteria evidently increased in drought-treated and salt-treated soil. Moreover, the variation of Cyanobacteria abundance caused by combined drought and salt stresses was stronger than that caused by single drought or salt stress. Functional meta-genomic profiling indicated that a series of sequences related to signaling transduction, defense mechanism and post-translational modification, protein turnover, chaperones were enriched in rhizosphere soil under stressed conditions, which might have implications for plant survival and stress tolerance. Drought and salt stress affectedpeanut growth and reduced pod yield. Results from this study would present reference on the future improvement of stress tolerance of peanuts via modifying soil microbial community.