Introduction: Understanding the underlying mechanisms of microbial community assembly is a fundamental topic in microbial ecology. As an integral part of soil organisms, ectomycorrhizal (EM) fungi play vital roles in ecosystems. Picea crassifolia is an important pine species in the Helan Mountains in Inner Mongolia, China, with high ecological and economic values. However, studies of EM fungal diversity and mechanisms underlying community assembly on this pine species are limited.Methods: In this study, we investigated EM fungal communities associated with P. crassifolia from 45 root samples across three sites in the Helan Mountains using Illumina Miseq sequencing of the fungal rDNA ITS2 region.Results: A total of 166 EM fungal OTUs belonging to 24 lineages were identified, of which Sebacina and Tomentella-Thelephora were the most dominant lineages. Ordination analysis revealed that EM fungal communities were significantly different among the three sites. Site/fungus preference analysis showed that some abundant EM fungal OTUs preferred specific sites. Ecological process analysis implied that dispersal limitation and ecological drift in stochastic processes dominantly determined the community assembly of EM fungi.Discussion: Our study indicates that P. crassifolia harbors a high EM fungal diversity and highlights the important role of the stochastic process in driving community assembly of mutualistic fungi associated with a single plant species in a semi-arid forest in northwest China.

Arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) form ubiquitous symbiotic relationships with plants through co-evolutionary processes, providing multiple benefits for plant growth, productivity, health, and stress mitigation. Mountain ecosystem multifunctionality is significantly influenced by mycorrhizal responses to climate change, highlighting the importance of understanding the complex interactions between these fungi and environmental variables. In this study, we investigated five vegetation zones across an altitudinal gradient (675–2157 m a.s.l.) in Wuyi Mountain, one of the most well-preserved mid-subtropical mountain ecosystems in eastern China. Using high-throughput sequencing, we examined the altitudinal distribution patterns, community assembly mechanisms, and network interactions of soil AMF and EMF. Our analyses demonstrated significant altitudinal variations in the composition and diversity of mycorrhizal fungal communities. AMF richness peaked in the subalpine dwarf forest at intermediate elevations, whereas EMF richness was highest in the low-altitude evergreen broad-leaved forest, showing a marked decrease in the alpine meadow ecosystem. β-diversity decomposition revealed that species turnover constituted the primary mechanism of community differentiation for both fungal types, explaining >56% of the observed variation. Stochastic processes dominated community assembly, with the relative importance of dispersal limitation and drift showing distinct altitudinal patterns. Network analysis indicated that AMF networks reached maximum complexity in evergreen broad-leaved forests, while EMF networks showed similar complexity levels in coniferous forests. Among the examined factors, soil properties emerged as the predominant driver of altitudinal variations in ecosystem multifunctionality, followed by AMF communities and climatic variables. These findings provide critical insights into the ecological functions and environmental adaptations of mycorrhizal fungi, advancing our understanding of their responses to environmental changes in mountain ecosystems and informing evidence-based conservation strategies.

A comprehensive understanding of genetic background for rare species will provide an important theoretical basis for the future species management, monitoring and conservation. Tetraena mongolica is restrictedly distributed in the western Ordos plateau of China and has been listed as a national protected plant. We generated 13 chloroplast (cp) genomes of T. mongolica (size range of 106,062–106,230 bp) and conducted a series of comparative analyses of six Zygophyllaceae cp genomes. T. mongolica cp genome exhibited a quadripartite structure with drastically reduced inverted repeats (IRs, 4,315 bp) and undergone the loss of a suit of ndh genes and a copy of rRNAs. Furthermore, all the T. mongolica populations were divided into two genetic groups based on complete cp phylogenomics. In addition, notably variable genome size, gene order and structural changes had been observed among the six Zygophyllaceae cp genomes. Overall, our findings provide insights into the cp genome evolution mode and intraspecific relationships of T. mongolica, and provide a molecular basis for scientific conservation of this endangered plant.

The phyllosphere constitutes a critical habitat for microorganisms, exerting profound influences on host vitality, developmental dynamics, reproductive functions, and stress resilience. However, the diversity and network structure of endophytic and epiphytic fungal communities within this microecosystem have not been thoroughly explored. In this investigation, high-throughput sequencing technologies were employed to assess the diversity, community composition, and network structure of endophytic and epiphytic fungal communities associated with Mussaenda pubescens across six geographically distinct locations in Southeast China. The results revealed significant differences in community composition and diversity between endophytic and epiphytic fungi, with pronounced geographical variation observed within these phyllosphere fungal communities. Network analysis indicated that epiphytic fungal networks possess enhanced complexity compared with their endophytic counterparts, although the latter exhibit greater network stability. Moreover, stochastic processes were identified as pivotal in shaping the composition of these fungal communities. This research substantially enriches our comprehension of the diversity and organizational mechanisms of phyllosphere fungal communities, providing novel insights into the modalities of species coexistence and the stability of community equilibrium within ecosystems. IMPORTANCE: This study employs high-throughput sequencing technologies to explore the fungal communities within the phyllosphere of Mussaenda pubescens across Southeast China, offering significant insights into plant mycobiome. It demonstrates geographical variations in these fungal communities, with epiphytic fungi exhibiting more complex interaction networks compared with the endophytic fungi. Crucially, the research indicates that stochastic processes play a substantial role in the composition of fungal communities. These findings enhance our comprehension of plant-associated microecosystems and underscore the intricate interplay of randomness in maintaining ecosystem stability and diversity.

The presence of the exotic Eucalyptus tree in crop-growing soil and the accumulation of its undecomposed leaves is a significant ecological hazard. The waxy coating on the leaves and the phenolic compounds takes a long time to break down under normal conditions. It is necessary to explore various fungi that can degrade these leaves for an eco-friendly solution to this problem. In this study, spores of nine native Trichoderma strains were produced on wheat agar using a lactic acid-induced sporulation strategy (LAISS). Trichoderma biosustained spores and Serendipita indica (SI) spores were applied to a rice field with accumulated Eucalyptus leaves under continuous ponding (CP) and alternate flooding and wetting conditions (AFW). Among the strains, TI04 (Trichoderma viride) and TI15 (Trichoderma citrinoviride) showed faster (5 days) and massive sporulation (1.06–1.38 × 10¹¹ CFU/g) in LAISS. In vitro, TI04 and TI15 biosustained on Eucalyptus leaves and improved rice seedling growth and SI infection under greenhouse conditions. In the rice-field experiment, Trichoderma-treatment had a threefold yield (percentage) increase from control, with TI04 (CP) increasing the yield by 30.79, TI04 (AFW) by 29.45, TI15 (CP) by 32.72, and TI15 (AFW) rising by 31.91. Remarkably, unfilled grain yield significantly decreased in all the Trichoderma treatments. Under AFW conditions, TI04 and TI15 showed a higher pH increase. Furthermore, TI04 and TI15 under AFW had higher water productivity (t ha⁻¹ cm⁻¹) of 0.0763 and 0.0791, respectively, and the highest rates (percentage) of SI colonization of 86.36 and 83.16, respectively. According to the findings, LAISS-produced Trichoderma spores can be applied to break down persistent wastes and restore agricultural ecosystems through increased mycorrhizae networking.