Potential effects of temperature levels on soil bacterial community structure

Abstract

Soil microorganisms play a crucial role in the response to global warming in terrestrial ecosystems. Soils with higher microbial diversity have more ecological functions, higher resistance to environmental stress and higher crop production capacity. At present, the research on the effect of temperature change on soil microorganisms mostly adopts the methods of outdoor infrared temperature measurement or exchange and transplantation of soil with different temperature zones. Here, we investigate how temperature gradients potentially affect soil bacterial communities to change. For this reason, we used indoor precise temperature control treatment and combined high-throughput sequencing with bioinformatics to systematically analyze the diversity and species composition of soil bacteria under different temperature gradients, and to clarify the variation trend and interaction relationships of different species with temperature gradients. The results showed that temperature significantly affected the Alpha diversity of soil bacterial communities (P<0.05).Soil bacteria has different sensitivity and adaptability to temperature. In the range of 0-40℃, insensitive bacteria includes Proteobacteria, Gemmatimonadetes and Chloroflexi. Sensitive bacteria includes Sphingomonas, Ellin6055 and norank_f_67-14. The main reaction types of two bacteria showed four trends: ① Proteobacteria and Sphingomonas showed an “arch” variation; ② Gemmatimonadetes and Chloroflexi showed “inverted arch”. ③ Norank_f_67-14 showed an “inverted S type” change; ④ Ellin6055 shows a” parabolic ” shape. In different classification levels such as phylum and genus, the higher the classification level is, the higher degree it is weakened by temperature on, and the lower the classification level is, the stronger effect temperature has on it. In short, when temperature changes, soil bacteria can respond positively or negatively according to their ability to adapt to temperature, and accordingly form certain regular changes.