Soil microbial-mediated sulfur cycle and ecological network under
typical desert halophyte shrubs
Abstract
The sulfur cycle is one of the geochemical element cycles in which
microorganisms play a key driving role. The microbial function of soil S
cycling in response to desert degradation, however, remains largely
unknown. We used metagenomics to analyze the characteristics of
microbial communities and their functional genes involved in the S
cycles under natural water gradients with three typical halophytes
shrubs in the Ebinur Lake Basin Desert, China. Our results showed that
the rhizosphere effect, water gradient, and halophyte type played a
major role in shaping the S cycle. On the whole, in the rhizosphere type
and low water environment, the functional genes involved in the S cycle
had high abundance, and the SOX system in Alhagi sparsifolia had
a high expression level. In the S cycle network structure, as the soil
water content decreased, the complexity in S gene networks increased,
showing the characteristics of clustering and high connectivity.
Indicates the strengthening mode in microbial interactions with the
water content. Interestingly, the negative correlation of the network
changed with the water content, and there was more competition among
communities under the low water gradient and more cooperation under the
high water gradient. Through the correlation between environmental
factors and the network, nitrate (NO 3
−) and soil available S (AS) constrained most S gene
ecology networks. The key species involved in the S cycle were
halophilic microorganisms. These results can enhance the understanding
of soil S biogeochemical processes and contribute to the mitigation of
desertification by improving soil conservation.