The rare and endangered plant species Abies fanjingshanensis, which has a limited habitat, a limited distribution area, and a small population, is under severe threat, particularly due to poor leaf health. The plant endophytic microbiome is an integral part of the host, and increasing evidence indicates that the interplay between plants and endophytic microbes is a key determinant for sustaining plant fitness. However, little attention has been given to the differences in the endophytic microbial community structure, network complexity, and assembly processes in leaves with different leaf health statuses. Here, we investigated the endophytic bacterial and fungal communities in healthy leaves (HLs) and non-healthy leaves (NLs) of A. fanjingshanensis using 16S rRNA gene and internal transcribed spacer sequencing and evaluated how leaf health status affects the co-occurrence patterns and assembly processes of leaf endophytic microbial communities based on the co-occurrence networks, the niche breadth index, a neutral community model, and C-score metrics. HLs had significantly greater endophytic bacterial and fungal abundance and diversity than NLs, and there were significant differences in the endophytic microbial communities between HLs and NLs. Leaf-health-sensitive endophytic microbes were taxonomically diverse and were mainly grouped into four ecological clusters according to leaf health status. Poor leaf health reduced the complexity of the endophytic bacterial and fungal community networks, as reflected by a decrease in network nodes and edges and an increase in degrees of betweenness and assortativity. The stochastic processes of endophytic bacterial and fungal community assembly were weakened, and the deterministic processes became more important with declining leaf health. These results have important implications for understanding the ecological patterns and interactions of endophytic microbial communities in response to changing leaf health status and provide opportunities for further studies on exploiting plant endophytic microbes to conserve this endangered Abies species.

Lycium barbarum is a plant of considerable economic importance in China. However, root rot poses a significant threat to its yield and quality, leading to substantial economic losses. The disparities in rhizosphere soil fungal communities between healthy and root-rot-affected L. barbarum have not been thoroughly explored. Delving into the dynamics between these fungal communities and the onset of root rot may provide pivotal insights for the biological control of this disease in L. barbarum, as well as aid in identifying fungi associated with the condition. In this study, we utilized rhizosphere soil samples from Ningqi No. 1, a distinguished cultivar of L. barbarum, as our experimental material. We assessed the composition and diversity of fungal communities in both diseased (D) and healthy (H) samples using Illumina MiSeq sequencing technology. The study’s findings revealed that the mean concentrations of total nitrogen (TN) and soil organic matter (SOM) were significantly higher in the healthy specimens when contrasted with the diseased ones, while the pH levels were notably increased in the latter group. Additionally, the alpha-diversity of fungal communities was observed to be greater within the healthy samples as opposed to the diseased samples. Marked distinctions in fungal diversity were discerned between the healthy (H) and diseased (D) samples. Ascomycota was identified as the predominant fungal phylum in both groups. In the healthy samples, beneficial fungi such as Plectosphaerella and Mortierella were prevalent, in contrast to the diseased samples, the relative abundances of Embellisia and Alternaria demonstrated remarkable increases of 89.59% and 87.41%, respectively. Non-metric Multidimensional Scaling (NMDS) illustrated clear distinctions in the composition of fungal communities between the healthy and diseased samples. Redundancy Analysis (RDA) indicated total nitrogen (TN), organic matter (SOM), total phosphorus (TP), Available Potassium (AK), pH, and Total Potassium (TK). Notably, pH showed a stronger correlation with the diseased samples, while TN and SOM were more significantly associated with the healthy samples.

Introduction: Plant trait networks (PTNs) reveal integrated adaptation strategies, but how elevational stress gradients reshape PTN architecture and influence species distribution remains unclear.Methods: We analyzed 14 leaf, stem, and root traits across 37 woody sapling species along a 600 – 2200 m elevational gradient on Mt. Fanjingshan, China. We linked PTN metrics (connectivity, modularity, hub traits) to environmental drivers and species distributions.Results: PTN integration increased with elevation, evidenced by declining average path length (R² = 0.93, P = 0.008) and graph diameter (R² = 0.92, P = 0.011), indicating intensified trait coordination at higher elevations. Modularity peaked at mid-elevations (unimodal pattern: R² = 0.97, P = 0.017), reflecting heightened trade-offs between stress tolerance and resource acquisition. Crucially, litter depth and soil phosphorus—not climate—were the primary drivers of PTN structure, jointly explaining 84.2% of variation (P = 0.011) and promoting integration via root-hub traits (specific root length, specific root area). Species distribution was strongly correlated with PTN efficiency (84.8% explained variance, P = 0.038), driven by reduced graph diameter, greater litter depth, and lower temperature.Discussion: These findings indicate that elevational stress selects for highly integrated PTNs optimized by belowground trait hubs and microhabitat buffering, highlighting litter-soil interactions as critical mediators of species distributions under climatic constraints.