Search Results (1,085)

The Yellow River floodplain relies on plantations for ecological restoration, yet the key factors influencing soil microbial communities remain poorly elucidated. In this study, we investigated soil microbial communities under four representative stand types (Populus tomentosa monoculture (PP), Salix matsudana monoculture (PS), Populus tomentosa-Robinia pseudoacacia mixed plantation (MPR), and Salix matsudana-Populus tomentosa mixed plantation (MSP)) in this region. Using high-throughput sequencing, we compared the soil microbial community composition and diversity across stands, and combined soil physicochemical measurements to evaluate the relationships between community variation and soil factors. The results indicated that soil physicochemical properties differed significantly among stand types, except for available phosphorus. Bacterial α-diversity was highest in MPR, whereas fungal α-diversity was highest in MSP. Variation in microbial community structure (β-diversity) was primarily explained by soil organic carbon, total nitrogen, pH, water content, and electrical conductivity, as indicated by redundancy analysis and Mantel tests. The dominant bacterial phyla were Acidobacteriota, Pseudomonadota (formerly Proteobacteria), and Actinomycetota, while the dominant fungal phyla were Ascomycota, Basidiomycota, and Mortierellomycota. These findings demonstrate significant variation in soil microbial communities among plantation types and highlight the important role of soil physicochemical properties in shaping microbial community composition. Full article

Grain for Green, as an important ecological restoration method, profoundly affects soil nitrogen (N) cycling by altering the soil physicochemical properties and microbial community. Soil nitrogen mineralization is a key process in the terrestrial N cycle. However, the dynamics and underlying driving mechanisms of soil N mineralization rate (Rmin) that respond to afforestation remain unclear. In this study, we selected a typical afforestation sequence in Northeast China, including farmland (F), 21-year-old larch plantation (L21), 42-year-old larch plantation (L42), and natural larch forest (NL). The soil Rmin, associated soil physicochemical properties, and microbial community characteristics were determined to explore the effects of afforestation on soil Rmin and its potential mechanisms of action. The results suggested that soil Rmin was ranked in the order of L42 (0.41 mg kg⁻¹ d⁻¹) > F (0.39 mg kg⁻¹ d⁻¹) > L21 (0.23 mg kg⁻¹ d⁻¹) (p < 0.05) along the afforestation sequence, with no significant difference between L42 and F. Compared to the L42, the NL exhibited significantly lower soil Rmin (0.23 mg kg⁻¹ d⁻¹) (p < 0.05). The changes in soil Rmin during the afforestation were significantly positively related to soil total N (TN) and organic carbon (SOC) concentrations, but significantly negatively related to pH (p < 0.05). Furthermore, the abundances of Proteobacteria and Acidobacteria (bacteria) and Ascomycota (fungi) were also closely correlated with soil Rmin. Structural equation modeling (SEM) analysis further indicated that the afforestation mainly regulated soil Rmin by altering soil temperature (ST) and NH₄⁺-N content. Meanwhile, soil NH₄⁺-N content could also exert a significantly positive effect on soil Rmin by influencing the microbial community. In conclusion, afforestation effectively altered soil Rmin, which was even higher in the plantation than in natural forests. This finding further enhances our understanding of forest restoration and land management practices on soil N cycling in temperate regions. Full article

The Bahía Blanca marshes are highly productive ecosystems that act as carbon sinks and support a diverse community of halophytic plants, including species of Distichlis, Spartina, Sarcocornia, among others. Marine fungi inhabit these ecosystems and play important roles in the decomposition of organic matter and the production of valuable biopolymers and metabolites. Despite their potential ecological and commercial importance, little is known about the identity and chemical profiles of these fungi associated with marine environments and halophytic plants in the Bahía Blanca estuary. To expand current knowledge of marine fungi in this system, three fungal species associated with marine waters and Sarcocornia perennis plants were isolated and identified: Aspergillus iizukae, Stemphylium sp. (Ascomycota), and Mucor sp. (Mucoromycota). Their biomass was analyzed to determine its biochemical and metabolic composition. Stemphylium sp. exhibited the highest protein (30.24 g/100 g dry mass) and lipid (2.65 g/100 g dry mass) contents, whereas Mucor sp. showed the highest levels of total sugars (26.13 g/100 g dry mass) and glucosamine (17.30 g/100 g dry mass). Aspergillus iizukae produced the greatest diversity of secondary metabolites. These findings provided a preliminary characterization of fungal species from this region and highlighted their potential for future biotechnological and industrial applications. Full article

Cultivable fungi are important components of freshwater ecosystems, yet their diversity in Amazonian aquatic environments remains poorly explored. This study evaluated cultivable fungal communities associated with water, sediment, and submerged wood in the Negro, Solimões, and Tapajós Rivers, representing the major black-, white-, and clear-water systems of the Amazon basin, respectively. Samples were collected along 25 m transects, fungi were isolated on potato dextrose agar, grouped into morphotypes, and identified morphologically. Diversity was assessed using richness, Shannon, Simpson, Pielou, and Sørensen indices. Overall, 130 isolates and 75 morphotypes were recorded, with a predominance of morphotypes assigned to filamentous Ascomycota and widespread occurrence of Aspergillus and Penicillium. Solid substrates yielded greater fungal abundance and richness than water samples. Submerged wood from the Negro River showed the highest overall cultivable fungal abundance, whereas the Tapajós River showed the highest diversity in water and sediment and the highest richness in both substrates. The Solimões River showed stronger dominance by a limited number of morphotypes, particularly in submerged wood. Sørensen similarity values indicated low compositional overlap among rivers, especially for submerged wood communities, suggesting apparent differentiation among river-associated cultivable fungal assemblages. Together, these exploratory results suggest that substrate type, hydrochemical differences, and potential temporal effects may be associated with the structure of cultivable fungal communities in Amazonian rivers. Full article

Natural saline–alkaline soils are widespread in Central Asia, yet microbial responses to salinity gradients and ionic composition remain poorly resolved. We profiled bacterial communities (16S rRNA V3–V4, Illumina MiSeq) in 20 topsoil (0–20 cm) samples from four regions of Kazakhstan spanning non-saline to highly saline conditions. Soil chemistry included pH, total mineralization (dry residue), and major ions (Na⁺, Cl⁻, SO₄²⁻, HCO₃⁻, Ca²⁺, Mg²⁺, K⁺). Alpha (Chao1, Shannon, observed ASVs) and beta diversity (Bray–Curtis; ANOSIM; PCoA) were evaluated across salinity classes. Soils were alkaline (pH 7.91–10.47) and covered a broad salinity range (256–26,312 mg/L), driven mainly by Na⁺ with chloride and/or sulfate. Alpha diversity remained stable across salinity classes, though dispersion increased under high salinity. Community composition differed significantly among classes (ANOSIM R = 0.428, p = 0.005), with partial PCoA separation and overlap, indicating gradual turnover along the salinity gradient. In contrast, fungal communities showed no significant response to salinity, with stable alpha and beta diversity across all samples and consistent dominance of Ascomycota. Communities were dominated by Actinomycetota (formerly Actinobacteriota), Bacteroidota, and Pseudomonadota (formerly Proteobacteria). Bacteroidota increased in highly saline soils (FDR q = 0.036), whereas Acidobacteriota decreased (FDR q = 0.052). Thermodesulfobacteriota (formerly Desulfobacterota) correlated positively with sulfate, and Cyanobacteriota negatively with chloride. Overall, Kazakhstan’s saline–alkaline soils show stable bacterial alpha diversity but moderate, ion-linked compositional shifts with enrichment of halotolerant taxa. Full article

Soil salinization severely constrains plant growth, yet the roles of ion composition and rhizosphere microbial communities in shaping plant performance remain poorly resolved. Here, we investigated multiple crop and wild plant species in saline–alkali soils and compared rhizosphere ion composition, microbial communities, and plant growth status. Restricted plant growth was consistently associated with elevated Na⁺ and Cl⁻ concentrations, while fungal diversity was significantly higher in well-growing plants. Ion composition (particularly Na⁺, Cl⁻, SO₄^2–, and Mg²⁺) was strongly correlated with microbial community structure, and a set of microbial taxa, including bacterial phyla such as Deinococcota and Gemmatimonadota and fungal phyla within Ascomycota and Basidiomycota, were repeatedly associated with plant growth status across species. Notably, plant species exhibited distinct apparent, threshold-like responses, and in several cases, plant growth differences were not fully explained by salinity levels alone, suggesting that rhizosphere microbial communities may buffer salt stress. Together, our results reveal that ion composition governs plant growth not only through direct ionic stress but also via microbially mediated pathways, highlighting an ion–microbe–plant interaction framework underlying growth variation in saline–alkali soils. Full article

The genus Xylaria (Xylariaceae, Ascomycota) comprises a morphologically and ecologically diverse group of fungi with a predominantly saprobic lifestyle, widely distributed in forest ecosystems worldwide. Despite its global occurrence, its diversity in European Atlantic laurel forests (laurisilva), both insular and continental, remains poorly understood. In this study, we examined more than 80 collections of Xylaria from laurisilva forests in Madeira and the Azores (Portugal), the Canary Islands (Spain), and relict laurel woodlands in mainland Iberia, documenting at least 13 species. Several collections could not be successfully sequenced, suggesting that additional taxa may occur. Among the identified species, eight are described here as new to science and are supported by morphological differences and multilocus phylogenetic analyses. Species delimitation was based on an integrative approach combining detailed morphological observations with phylogenetic inference from ITS, LSU, RPB2, and TUB2 loci. Our results reveal a substantially higher diversity of Xylaria in these ecosystems than previously recognized and confirm the importance of multilocus frameworks for resolving species boundaries, particularly in morphologically cryptic lineages. This study expands the known diversity of Xylaria in Europe and identifies Atlantic laurel forests as important reservoirs of fungal diversity and evolutionary novelty. Full article

Background: Symbiotic fungi play essential roles throughout the entire cycle of orchid plants, including seed germination, seedling development, and maturation. Dendrobium officinale Kimura & Migo (Orchidaceae) (D. officinale) is a rare and highly valued traditional Chinese medicinal herb. Currently, artificial breeding using tissue culture technology is widely adopted and essential in the Dendrobium industry; however, this approach may impair or disrupt the plant’s ability to establish and maintain symbiotic relationships with mycorrhizal fungi. Methods: In this study, the fungal endophyte community (FEC) in the roots of D. officinale cultivated under four different modes was analyzed using high-throughput sequencing. Correlation analyses were also carried out to examine the relationships between bioactive compounds and the FEC. Results: (1) The FEC in D. officinale roots was dominated by Ascomycota and Basidiomycota, with significant differences in abundance, diversity, and community structure among cultivation modes; (2) the FEC under greenhouse cultivation differed significantly from those under tree epiphytic cultivation in terms of fungal nutritional types and dominant taxa; (3) six major mycorrhizal fungal taxa were identified in Dendrobium roots, although non-mycorrhizal fungi accounted for approximately 97% of the community; and (4) polysaccharide content in Dendrobium stems was positively correlated with certain root fugal endophytes (Exophiala, alaromyces, Pseudodactylaria, and Fellomyces). Conclusions: This study provides a foundation for understating the growth of D. officinale under different cultivation modes and highlights the relationship between bioactive compound accumulation and fungal endophyte communities. Full article

Soil depth and habitat degradation can reshape fungal communities in salt-affected wetlands, but their effects on fungal ecological processes remain insufficiently understood. This study examined soil fungi in the Halahai Provincial Nature Reserve and adjacent converted farmland in the western Songnen Plain, Northeast China, where salt-affected meadow soils correspond mainly to Solonetz. Four habitat types—reed wetland, meadow steppe, degraded Suaeda saline patch, and converted farmland—were sampled at 0–20 cm and 20–40 cm soil depths. Soil properties, fungal diversity, taxonomic composition, environmental associations, niche breadth, assembly processes, and FUNGuild-based trophic modes were analyzed using ITS sequencing. Degraded Suaeda soils showed the strongest salinity–alkalinity stress, with pH values of 10.34–10.30 and electrical conductivity of 1.70–1.75 dS·m⁻¹. Fungal richness was highest in surface-converted farmland, with a Sobs value of 423.33, and lowest in deeper degraded Suaeda soil, with a Sobs value of 86.00. Ascomycota dominated most groups, especially degraded Suaeda soils, where its relative abundance reached 75.29–76.80%. ANOSIM confirmed significant community dissimilarity among habitat-depth groups (R = 0.56878, p = 0.001). Specialists accounted for 68.07% of fungal taxa, and stochastic processes, especially drift and dispersal limitation, contributed substantially to assembly. These results indicate that soil depth, salinity–alkalinity, and habitat conversion jointly regulate fungal community structure and ecological processes in degraded soda saline–alkali wetlands. Full article

Pear fruits host diverse microbial communities that influence postharvest quality, spontaneous fermentation, and susceptibility to microbial contamination. This study characterizes the fungal communities associated with naturally fallen overripe pears (Pyrus communis) using ITS2 amplicon sequencing combined with culture-dependent approaches. The fungal community exhibited low diversity and was dominated by Ascomycota (99%), primarily Saccharomycetes (91.8%), with Hanseniaspora, Aureobasidium, and Microcyclospora representing more than 90% of the total microbial community. Culture-dependent isolation confirmed Hanseniaspora uvarum as the dominant yeast species (~89%), followed by Metschnikowia spp. and Pichia spp. Pairwise co-culture assays, quantified using the Relative Interaction Index, demonstrated predominantly competitive interactions, with fast-growing H. uvarum exerting suppressive effects on slower-growing species. Among the isolated yeasts, Metschnikowia fructicola exhibited antibacterial activity against all tested bacteria Staphylococcus aureus, Listeria innocua and Salmonella typhimurium. The strongest antibacterial activity was exerted against the foodborne pathogen S. aureus. In a pear juice model system, co-cultivation with M. fructicola resulted in the elimination of S. aureus within four days, while yeast viability was maintained. These findings observe the fermentative yeasts distributed in overripe pears and demonstrate the potential of M. fructicola to inhibit bacterial growth under controlled conditions. The results provide a preliminary basis for further studies on fungal succession, yeast interactions, and the biocontrol potential of pear-associated yeasts. For broader ecological conclusions, larger-scale studies across locations, seasons, cultivars, and decay stages are required. Full article

Background: Root rot caused by Fusarium solani is a devastating disease in Angelica sinensis (danggui), leading to severe yield and quality losses. Sustainable control strategies are urgently needed. According to the plant “cry for help” theory, plants under pathogen attack may recruit beneficial microbes via root exudates. However, whether A. sinensis employs this strategy against F. solani remains unknown. This study aimed to identify potential “cry for help” metabolites and evaluate their biocontrol potential. Methods: LC-MS analysis revealed that F. solani infection significantly altered the metabolic profiles of both A. sinensis roots and rhizosphere soil. Results: Comparative analysis identified seven metabolites specifically upregulated in infected plants but not detected in the pathogen, including taurine, oxoadipic acid, quinolinic acid, 6-phosphogluconic acid, methyl cinnamate, 2-phenylethanol, and (R)-3-hydroxybutyric acid. Exogenous application of these seven metabolites revealed that taurine and methyl cinnamate significantly alleviated disease symptoms, improved plant growth (root length, biomass), and enhanced the activities of key defense enzymes (peroxidase, POD, phenylalanine ammonia-lyase, PAL, lipoxygenase, LOX, polyphenol oxidase, PPO). Furthermore, taurine and methyl cinnamate reshaped the rhizosphere microbiome. The incidence of root rot was reduced by 51.3% and 50.8%, respectively. Taurine enriched actinobacteria (e.g., Paeniglutamicibacter) and reduced the relative abundance of pathogenic Ascomycota fungi, while methyl cinnamate markedly enriched the nitrogen-fixing bacterium Azotobacter and the saprophytic fungus Schizothecium. Crucially, both treatments significantly suppressed the proliferation of F. solani in the rhizosphere. Conclusions: Our findings demonstrate for the first time that A. sinensis activates a “cry for help” response upon attack by F. solani, with taurine and methyl cinnamate preliminarily identified as key signaling metabolites that can directly or indirectly inhibit the development of A. sinensis root rot. These compounds enhance plant resistance and recruit beneficial microorganisms, offering a novel and promising ecological strategy for the green control of A. sinensis root rot. Full article

Organic-matter degradation and humification degree are key determinants of compost quality. In this study, we used pig manure and wheat straw to investigate the effects of diatomite on organic-component degradation, humification, and fungal community succession. In a 40-day aerobic composting experiment, we compared a control treatment with treatments supplemented with 4% and 8% diatomite. The results indicated that diatomite significantly accelerated organic-matter degradation and humification, with 8% diatomite increasing organic matter and lignin degradation by 9.05% and 9.27%, respectively. Based on linear interpolation of the HA/FA ratio dynamics, it was estimated that the maturity threshold (a ratio of humic acid to fulvic acid > 1.6) was reached 5–7 days earlier in the group subjected to 8% diatomite treatment relative to the control. Fungal community analysis revealed that the 8% diatomite treatment effectively alleviated fungal suppression under high-temperature conditions. By the maturation phase, fungal richness and diversity in the group subjected to the 8% diatomite treatment reached 1.8 and 2.6 times that of the control, respectively, significantly promoting the colonization and recovery of thermophilic Ascomycota, including Mycothermus and Aspergillus. Diatomite shifted fungal interactions from competition to symbiotic cooperation centered on Mycothermus, with partial least squares path modeling confirming fungal composition was a primary regulator of humification. This study demonstrates that 8% diatomite enhances composting efficiency and humification quality by optimizing fungal community structure and function, offering a theoretical and practical basis for the use of agricultural waste resources. Full article

‘Fengtang’ plum is increasingly cultivated in southern China under mountain cultivation conditions, which involve lower temperatures, higher irradiance, and thinner soils. These conditions may uniquely shape the rhizosphere microbiome and influence tree health, yet their effects remain poorly understood. This study aimed to characterize the structural and taxonomic characteristics of the rhizosphere microbial community of ‘Fengtang’ plum grown under mountain cultivation conditions, and to identify key microbial groups associated with plant growth. We performed 16S rRNA and ITS high-throughput sequencing on rhizosphere and non-rhizosphere soil samples from ‘Fengtang’ plum orchards. Significant differences in α-diversity and β-diversity were observed between rhizosphere and non-rhizosphere communities. Dominant bacterial phyla included Pseudomonadota, Actinobacteriota, Acidobacteriota, and Chloroflexi; Ascomycota and Basidiomycota dominated in fungal communities. Dominant microbial groups were consistent across phylum, class, and order levels. Beneficial genera such as Streptomyces, Bacillus, and Rhizobium were enriched in the rhizosphere, and are considered putative core functional genera based on their known plant-growth-promoting traits. The microbial community in the rhizosphere shows distinct compositional patterns that may be linked to microecological balance. This study seeks to provide a comprehensive perspective for understanding the microbial communities associated with the plum tree rhizosphere. Full article

The cell wall (CW) of Mucoromycota has a unique chitin/chitosan complex, unlike chitin/glucan complex in Ascomycota. Under cell wall stress (CWS), induced by azo dyes, ascomycetes increase the amount of CW chitin. This study analyzes the response of Mucor flavus to CWS, induced by Congo red and Calcofluor white. It was found that azo dyes significantly reduced the biomass yield and inhibited apical growth and branching but did not lead to an increase in the amount of CW chitin/chitosan, neutral polysacchrides and cytosol osmolytes. Non-bilayer phosphatidic acids and phosphatidylethanolamines dominated in the control membrane lipids, but the proportion of bilayer phosphatidylcholines did not exceed 5%. Under CWS, the proportion of phosphatidic acids increased, while the proportion of phosphatidylethanolamines decreased and the degree of unsaturation of phospholipids increased. Storage lipids in the control were represented by mono-, di- and triacylglycerides and free fatty acids. Under CWS, the proportion of diacylglycerides increased significantly, while the proportion of triacylglycerides decreased. Thus, the CWS response of M. flavus consisted of significant changes in growth and the composition of membrane and storage lipids, but the amount of CW chitin/chitosan and cytosol osmolytes did not increase, which is different from the response of ascomycetes. Full article

The effects of pre-harvest application of Bacillus velezensis LYB73 on rhizosphere soil properties, microbial communities, fruit quality, and flavor-related traits in different peach cultivars are still not well understood. In this study, three peach cultivars, “Jinxia” (JX), “Wanhujing” (WHJ), and “Youpantao” (YPT), were subjected to B. velezensis LYB73 treatment or a sterile-water control under field conditions. Rhizosphere bacterial (16S rRNA) and fungal (ITS) communities were analyzed by high-throughput sequencing. Soil physicochemical properties, fruit nutritional and functional components, antioxidant capacity, and electronic sensory traits were also evaluated. The application of LYB73 was associated with lower rhizosphere soil pH (5.52–6.82) and changes in several soil nutrient-related parameters. Microbial community analyses indicated that LYB73 treatment was accompanied by shifts in the composition of rhizosphere bacterial and fungal communities. For example, the relative abundance of Pseudomonadota increased in the JX treatment group, while Ascomycota was enriched in the JX and YPT treatment groups. At the genus level, taxa such as Gemmatimonas, Saitozyma, and Cephalotrichum showed increased relative abundance in some treated groups. Compared with the control, LYB73-treated fruits generally showed higher levels of reducing sugars, titratable acids, amino acids, total phenols, total flavonoids, and antioxidant capacity. The magnitude of these responses varied among cultivars: JX showed larger increases in total phenols, total flavonoids, and DPPH scavenging activity, WHJ showed a greater increase in amino acids and ABTS scavenging activity, and YPT showed the largest increase in superoxide anion scavenging activity. Electronic sensory analysis further suggested that LYB73 treatment affected taste and aroma-related traits, although the responses differed among cultivars. Correlation analysis showed that several dominant microbial genera were significantly associated with soil properties, fruit quality indices, and sensory indicators. Overall, these results suggest that pre-harvest application of B. velezensis LYB73 may influence rhizosphere microecology and fruit quality in a cultivar-dependent manner, providing preliminary support for its potential use in peach production. Full article