Onshore soil microbes and endophytes respond differently to geochemical and mineralogical changes in the Aral Sea.

There is limited knowledge about how microbiome develops along the geochemical and mineralogical change in onshore soils derived from continuous desiccation of lakes. In this study, geochemistry and mineralogy were studied in the Aral Sea onshore soils exposed in different periods (from the 1970s to 2018), followed by microbial analyses on the studied soils and the aboveground organs of dominant plants. The soils exhibited an increasing gradient of total soluble salts (TSS: 0.4-0.5 g/L to 71.3 g/L) and evaporite minerals (e.g., gypsum, halite) from the farshore to the nearshore. In the studied soils, microbial diversity decreased with increasing TSS, and microbial community dissimilarities among samples was positively correlated with the contents of gypsum and calcite minerals. Among the measured environmental variables, minerals contributed most to the observed microbial variation. In contrast, the endophytic microbial communities in the aboveground organs of dominant plants were not related to any of the measured variables, indicating that they differed from their soil counterparts with respect to their responses to geochemical and mineralogical variations in soils. In summary, these results help us understand the response of onshore soil microbiome to the decline of lake water caused by continuous desiccation.