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Background: Phylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region., Results: The resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise., Conclusions: These findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution., (© 2024. The Author(s).)

Background: Rhizosphere and endophytic fungi play important roles in plant health and crop productivity. However, their community dynamics during the continuous cropping of Knoxia valerianoides have rarely been reported. K. valerianoides is a perennial herb of the family Rubiaceae and has been used in herbal medicines for ages. Here, we used high-throughput sequencing technology Illumina MiSeq to study the structural and functional dynamics of the rhizosphere and endophytic fungi of K. valerianoides., Results: The findings indicate that continuous planting has led to an increase in the richness and diversity of rhizosphere fungi, while concomitantly resulting in a decrease in the richness and diversity of root fungi. The diversity of endophytic fungal communities in roots was lower than that of the rhizosphere fungi. Ascomycota and Basidiomycota were the dominant phyla detected during the continuous cropping of K. valerianoides. In addition, we found that root rot directly affected the structure and diversity of fungal communities in the rhizosphere and the roots of K. valerianoides. Consequently, both the rhizosphere and endophyte fungal communities of root rot-infected plants showed higher richness than the healthy plants. The relative abundance of Fusarium in two and three years old root rot-infected plants was significantly higher than the control, indicating that continuous planting negatively affected the health of K. valerianoides plants. Decision Curve Analysis showed that soil pH, organic matter (OM), available K, total K, soil sucrase (S&#95;SC), soil catalase (S&#95;CAT), and soil cellulase (S&#95;CL) were significantly related (p < 0.05) to the fungal community dynamics., Conclusions: The diversity of fungal species in the rhizosphere and root of K. valerianoides was reported for the first time. The fungal diversity of rhizosphere soil was higher than that of root endophytic fungi. The fungal diversity of root rot plants was higher than that of healthy plants. Soil pH, OM, available K, total K, S&#95;CAT, S&#95;SC, and S&#95;CL were significantly related to the fungal diversity. The occurrence of root rot had an effect on the community structure and diversity of rhizosphere and root endophytic fungi., (© 2024. The Author(s).)

Proteomics has been used extensively in the field of mycology, mainly in trying to understand the complex network of protein-protein interactions that has been implicated in the molecular functions of fungi. It is also a useful tool to compare metabolic differences within a genus. Species of Pseudogymnoascus , a genus under the phyla Ascomycota, have been shown to play an important role in the soil environment. They have been found in both polar and temperate regions and are a known producer of many extracellular hydrolases that contribute to soil decomposition. Despite the apparent importance of Pseudogymnoascus spp. in the soil ecosystem, investigations into their molecular functions are still very limited. In the present study, proteomic characterization of six Pseudogymnoascus spp. isolated from three biogeographic regions (the Arctic, Antarctic, and temperate regions) was carried out using tandem mass spectrometry. Prior to proteomic analysis, the optimization for protein extraction was carried out. Trichloroacetic acid‑acetone‑phenol was found to be the best extraction method to be used for proteomic profiling of Pseudogymnoascus spp. The proteomic analysis identified 2003 proteins that were successfully mapped to the UniProtKB database. The identified proteins were clustered according to their biological processes and molecular functions. The shared proteins found in all Pseudogymnoascus spp. (1201 proteins) showed a significantly close relationship in their basic cellular functions, despite differences in morphological structures. Analysis of Pseudogymnoascus spp. proteome also identified proteins that were unique to each region. However, a high number of these proteins belonged to protein families of similar molecular functions, namely, transferases and hydrolases. Our proteomic data can be used as a reference for Pseudogymnoascus spp. across different global regions and a foundation for future soil ecosystem function research.

A yeast strain (CGMCC 2.6937 T ) belonging to the ascomycetous yeast genus Saturnispora was recently isolated from soil collected in Xinghuacun, Shanxi Province, PR China. The strain produces one or two ellipsoid or spherical ascospores in asci formed by the conjugation between a cell and its bud. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene suggest that this strain is conspecific with strains NYNU 14639 isolated from rotten wood collected in Funiu Mountain, Henan province and ES13S05 from soil collected in Nantou County, Taiwan. The CGMCC 2.6937 T group is most closely related to Saturnispora dispora and Saturnispora zaruensis . However, strain CGMCC 2.6937 T differs from S. dispora by 17 (3.2 %, 13 substitutions and four gaps) and 77 (18.8 %, 52 substitutions and 25 gaps) mismatches, and from S. zaruensis by 15 (2.9 %, 12 substitutions and three gaps) and 64 (15.6 %, 44 substitutions and 20 gaps) mismatches, in the D1/D2 domain and ITS region, respectively. The results suggest that the CGMCC 2.6937 T group represents an undescribed species in the genus Saturnispora , for which the name Saturnispora sinensis sp. nov. is proposed. The holotype strain is CGMCC 2.6937 T .