Despite desert ecosystem being crucial to our understanding of natural geography, species evolution and global climate change, there is limited information on the dynamics of their composition and the diversity of endophytic fungi communities driven by plant identity and organ differentiation. Here, an extensive investigation of endophytic fungal microbiome in root, stem, and leaf organs associated with five xerophyte shrubs in an extremely arid desert, Northwest China, were examined. The fungal community dominated by Dothideomycetes and Pleosporales. Shrub species strongly drive the niche-based processes of endophytic fungi across the root, stem and leaf compartments. The diversity and composition of endophytic fungi in stem showed higher variability among plant species than leaf and root. The fungal communities in root libraries were more diverse and exhibited a remarkable differentiation of community composition. We further demonstrated the significant host preferences and tissue specificity of desert endophytic fungi, and unique specific taxa were also observed. The co-occurrence network revealed the coexistence of fungal endophytes in arid desert, and the root fungal network harbored the highest interspecies connectivity. Members of Pleosporales were the most common keystone species in the root fungal network. This is the first report of mycobiota in both plant species and organ differentiation in an extremely arid desert ecosystem.

Endophytic fungi isolated from plants under drought stress have been evidenced to confer hosts adaptive benefits to withstand drought. In this study, endophytic fungi associated with five typical desert shrubs in different tissue from extremely arid desert in Northwest China were investigated based on ITS sequence analysis. A total of 158 endophytic fungal stains were isolated from 1088 tissue segments of 12 samples, and 28 taxa represented by 25 species and 15 genera were identified as Ascomycetes. Alternaria sp. was the dominant genus with generic abundance ranging from 20% to 65%. The colonization rate of root was significantly lower, but the root-endophytic fungi (19 species) conversely presented a higher diversity than stem and leaf (11 and 7 species, respectively). Endophytic fungi had pronounced relative host and tissue preferences, while tissue explained more endophytic fungal variation than plant species. Additionally, soil pH, organic carbon, and phosphatase elicited significant responses from fungal species, which significantly affected the species richness of Fusarium redolens, Alternaria chlamydospore, Didymella glomerata, and Xylariales sp. This research provides a basis for the further understanding of the ecological distribution of endophytic fungi associated with xerophytic plants and their potential application for vegetative restoration and agricultural cultivation in drylands.

Aims: To mitigate Chinese yam continuous cropping obstacles, this study assessed single and mixed dark septate endophyte (DSE) inoculation effects on yam growth, soil characteristics and rhizosphere microbial communities, offering references for optimizing rhizosphere microenvironment of continuously cropped medicinal plant soils. Methods and results: 9 DSE strains were isolated from yam roots for single/mixed seedling pot inoculation; We found that growth-promoting effects differed by strain. Acrocalymma and Setophoma terrestris were the most commonly isolated DSE species, but strains with lower isolation rates Paraphoma ledniceana, Amesia atrobrunnea, and Zopfiella pilifera exhibited the most pronounced positive effects on yam root biomass. Increasing the number of co-inoculated strains did not proportionally enhance yam growth but progressively restructured soil microbial communities. However, mixed DSE inoculation as a whole showed no obvious growth promotion compared with the control. Fungal co-occurrence networks exhibited higher modularity and clustering, while bacterial communities had greater connectivity, especially under P. ledniceana and Fusarium sp. inoculation. Biosynthesis was the most abundant predicted function of rhizosphere microbes, with bacteria predicted to be enriched in detoxification and fungi in degradation-related pathways. Two strains of Chaetomiaceae and Periconia epilithographicola increased soil pH, organic carbon and available phosphorus, while available nitrogen decreased after DSE inoculation. Importantly, P. epilithographicola inoculation enhanced mycorrhizal fungi and mitigated microbial imbalance. Conclusions: Single and mixed DSE inoculations regulate rhizosphere microbial assembly and nutrient cycling via species-specific effects. Screening beneficial DSE consortia and characterizing their influence on rhizosphere networks provides preliminary theoretical insights and and candidate strains that may relieve yam replant obstacles in future applications.