UNASSIGNED: Here, we applied metagenomics technology to investigate the response of microbial carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) cycling and the key genes to salinity, and discuss the effects of edaphic variables on microbial functions.
UNASSIGNED: We found that carbon fixation dominated the carbon cycle. Nitrogen fixation, denitrification, assimilatory nitrate reduction (ANRA), and nitrogen degradation were commonly identified as the most abundant processes in the nitrogen cycle. Organic phosphorus dissolution and phosphorus absorption/transport were the most enriched P metabolic functions, while sulfur metabolism was dominated by assimilatory sulfate reduction (ASR), organic sulfur transformation, and linkages between inorganic and organic sulfur transformation. Increasing salinity inhibited carbon degradation, nitrogen fixation, nitrogen degradation, anammox, ANRA, phosphorus absorption and transport, and the majority of processes in sulfur metabolism. However, some of the metabolic pathway and key genes showed a positive response to salinization, such as carbon fixation (facA, pccA, korAB), denitrification (narG, nirK, norBC, nosZ), ANRA (nasA, nirA), and organic phosphorus dissolution processes (pstABCS, phnCD, ugpAB). High salinity reduced the network complexity in the soil communities. Even so, the saline microbial community presented highly cooperative interactions. The soil water content had significantly correlations with C metabolic genes. The SOC, N, and P contents were significantly correlated with C, N, P, and S network complexity and functional genes. AP, NH4+, and NO3- directly promote carbon fixation, denitrification, nitrogen degradation, organic P solubilization and mineralization, P uptake and transport, ASR, and organic sulfur transformation processes.
UNASSIGNED: Soil salinity in arid region inhibited multiple metabolic functions, but prompted the function of carbon fixation, denitrification, ANRA, and organic phosphorus dissolution. Soil salinity was the most important factor driving microbial functions, and nutrient availability also played important roles in regulating nutrient cycling.
■这里,我们应用宏基因组学技术研究了微生物碳(C)的反应,氮(N),磷(P),硫(S)循环和盐度的关键基因,并讨论了各变量对微生物功能的影响。
■我们发现碳固定主导了碳循环。固氮,反硝化,同化硝酸盐还原(ANRA),和氮降解通常被认为是氮循环中最丰富的过程。有机磷溶解和磷吸收/转运是最丰富的磷代谢功能,而硫代谢以同化硫酸盐还原(ASR)为主,有机硫转化,以及无机和有机硫转化之间的联系。盐度增加抑制了碳降解,固氮,氮降解,anammox,ANRA,磷的吸收和运输,以及硫代谢中的大部分过程。然而,一些代谢途径和关键基因对盐碱化表现出积极的反应,如碳固定(facA,pccA,korAB),反硝化(NAG,nirk,norBC,nosZ),ANRA(nasa,nirA),和有机磷溶解过程(pstABCS,phnCD,ugpAB)。高盐度降低了土壤群落的网络复杂性。即便如此,盐渍微生物群落呈现高度合作的相互作用。土壤含水量与C代谢基因有显著相关性。SOC,N,P含量与C显著相关,N,P,和S网络复杂性和功能基因。AP,NH4+,和NO3-直接促进碳固定,反硝化,氮降解,有机磷的溶解和矿化,磷的吸收和转运,ASR,和有机硫转化过程。
■干旱区土壤盐分抑制多种代谢功能,但是促进了碳固定的功能,反硝化,ANRA,和有机磷溶解。土壤盐分是驱动微生物功能的最重要因素,养分的可利用性在调节养分循环中也起着重要作用。