Inconsistent response of bacterial phyla diversity and abundance to soil salinity in a Chinese delta

Abstract

Soil salinization is an increasingly serious problem and decreases crop yields in the Yellow River Delta (YRD), but its effects on bacterial community and diversity at the phylum level are not well known. We used high-throughput sequencing of soil bacterial 16S rRNA to identify soil bacterial communities and diversity across a gradient of soil salinity (electrical conductivity), namely, S1: low salinity level (1.78 ds/m), S2: medium salinity level (3.16 ds/m), S3: high salinity level (17.26 ds/m), S4: extreme salinity level (34.41 ds/m), and a non-salted site as the control (CK, 0.92 ds/m). Our results indicated the significantly higher values of soil C/N ratio in S2, S3, and S4 compared with that in CK. Significantly lower values of the Shannon and Chao 1 indexes were observed in S4 compared with the CK (p < 0.05). High salinity decreased the relative abundance of Actinobacteria and Acidobacteria, but increased that of Gemmatimonadetes and Bacteroidetes. Additionally, the Shannon diversity of Bacteroidetes increased by 15.5% in S4 compared with that in the CK. Our results indicate that soil salt is a main factor regulating bacterial phyla diversity and community in the extremely saline-alkaline soils of YRD. The high abundance and diversity of Bacteroidetes can be used for saline-alkali land restoration.

Maize (Zea mays L.) Seedlings Rhizosphere Microbial Community as Responded to Acidic Biochar Amendment Under Saline Conditions

“…However, biochar amendment increased the bacterial richness and diversity under salinity stress. The results of our study are in accordance with the findings of Yang et al (2021), who reported that extreme salinity (34.41 dS m −1 ) lowered significantly Shannon, Ace, and Chao 1. However, Han et al (2017) investigated that biochar application had shown a positive effect on the bacterial structure under saline conditions.…”

“…Zhang et al (2021) has reported that increasing some phylum (Bacteroidetes, Gemmatimondetes, and Firmicutes) and bacterial communities showed tolerance and strongly structured with increasing salinity stress. In contrast, Yang et al (2021) revealed that extreme salinity levels (34.41 dS m −1 ) significantly decreased the abundance of Proteobacteria, Actinobacteria, and Acidobacteria. The pH has a great impact on the relative abundance of bacteria on phylum and genus levels (Wang et al, 2019).…”

“…This is because a high abundance of Firmicutes, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Deinocococcus-Thermus, and Patescibacteria were found at high salinity. Some bacterial species may be salt dependent and/or salt tolerant ( Yang et al, 2021 ). Therefore, some of the abundances of some bacterial species increased at high salt levels.…”

“…Some species of bacteria may take time to break down the organic C for the survival of microbiota. Different bacterial species show a different level of tolerance to salt even under the same phylum ( Yang et al, 2021 ). The response of the microbial community to biochar application is dependent on its type, duration, soil conditions, and properties, such as biochar pH and pyrolysis temperature ( Cho et al, 2016 ; Fan et al, 2020 ; Xu et al, 2021 ).…”

Effects of Fishery Utilization on the Physicochemical Index and Microbial Community Composition in Saline-Alkaline Water

“…Existing studies on microbial community diversity in saline-alkaline land focused on soils. High salinity increased the relative abundance of Gemmatimonadetes and Bacteroidetes and reduced the relative abundance of Actinobacteria and Acidobacteria in the Yellow River Delta . Firmicutes and Bacteroidetes were positively correlated with salinity in Xinjiang .…”