摘要
Desert soil microbiomes play a pivotal role in combating desertification through symbiotic relationships with plants and regulating elemental cycling processes,but their knowledge remains limited.In this study,soil samples were collected at various depths(0-30,30-60,60-100,and 100-200 cm)in the pre-growth period(June 14 and 20,2021),peak growth period(July 11,2021),and post-growth period(September 18,2021)of desert plants(mainly Alhagi sparsifolia)in the Taklimakan Desert of China,to assess shifts in community diversity,structure,and interactions of soil archaea,bacteria,and fungi with increasing soil depth and to identify the driving mechanisms behind these changes.Significant variations(R2＞0.32)in microbial composition were observed across soil depths,but variations between growth periods were relatively minor(R2＜0.11).Compared with those in surface soil(0-30 cm),the ACE and Shannon index decreased by 6.7％-18％for archaea and by 1.0％-11％for bacteria at 30-60,60-100,and 100-200 cm depths,while the fungal Shannon index increased by 5.9％-18％.As soil depth increased(from 0-30 to 30-60,60-100,and 100-200 cm),the relative abundance of Thaumarchaeota in archaea decreased by 11％-22％,while in bacteria,Actinobacteriota increased by 5.9％-18％and Proteobacteria and Chloroflexi exhibited reductions of 29％-39％and 14％-20％,respectively.In fungal communities,the relative abundance of Ascomycota increased by 11％-13％,whereas Mucoromycota decreased by 12％-13％.Additionally,archaeal network complexity decreased with soil depth,characterized by a 51％-96％decrease in average degree.In contrast,bacterial network complexity and stability increased,characterized by a 61-239-fold increase in average degree and a 5.4％-27％increase in negative correlation ratio.Fungal networks showed minimal change in topological parameters across soil depths.Collectively,soil pH and nutrients(nitrogen,phosphorus,and potassium)further influenced microbial interactions and stability by altering microbial community diversity and structure.Our findings provide new insights into the vertical distribution and distinctive response patterns of soil microbiomes within desert ecosystems and emphasize the crucial role of microbial community diversity in maintaining microbial interactions and further driving microbe-mediated ecosystem functions.
