Search Results (72)

In this study, the dominant pathogenic fungus of gray spot disease in loquat, which was isolated from postharvest decaying loquat fruits in Zhenjiang, was identified as Pestalotiopsis vismiae (P. vismiae) by morphological characteristics and DNA sequencing. At the same time, a strain of yeast E1, which could effectively inhibit the pathogen, was isolated from the loquat leaves and soil and identified as Metschnikowia pulcherrima (M. pulcherrima) by morphological and molecular biological characteristics. It significantly reduced the natural decay of loquat fruits without affecting fruit quality. Metschnikowia pulcherrima E1 (M. pulcherrima E1) exhibited significant biocontrol efficacy against P. vismiae, the causal agent of gray spot in loquat, reducing disease incidence to 22.73% compared to 100% in the control group. Transcriptome analysis revealed 1444 differentially expressed genes (DEGs) (1111 upregulated, 333 downregulated), with key genes (CML19, XTH23, GSTU10) validated by RT-qPCR. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted enrichment in plant–pathogen interactions, glutathione metabolism, and phenylpropanoid biosynthesis. These findings provided molecular insights into yeast-induced resistance, bridging biocontrol applications with mechanistic studies. Full article

As a beneficial fungus, Trichoderma harzianum (T. harzianum) has been widely applied for growth promotion and biocontrol. Recently, it has attracted much attention with regard to improving stress tolerance in plants under abiotic stress. In this paper, the multiple mechanisms of T. harzianum for alleviating abiotic stress damage in plants are reviewed. T. harzianum can regulate the synthesis of key phytohormones, such as abscisic acid (ABA), indole-3-acetic acid (IAA), etc., thereby enhancing the physiological response ability of plants under stress conditions such as drought, salt stress, and high temperature. These are associated with antioxidant system regulation in plants, which reduces levels of reactive oxygen species (ROS) and oxidative damage and maintains intracellular redox balance. T. harzianum can also improve plant nutrient uptake and root development, secondary metabolism, soil environment and structure, and expression of related genes. In addition, in this paper, the characteristics of T. harzianum application in field and horticultural crops are summarized and compared, revealing differences in the methods, concentrations, time, and effects of applying T. harzianum to various crops. We further explore the synergistic regulation effect of T. harzianum and plant–microbiome interaction on the stress microenvironment. Future perspectives on the molecular mechanism of T. harzianum and its field application potential are discussed. This review provides a theoretic and practical reference for the application of T. harzianum in agricultural production. Full article

Understanding species-specific mechanisms governing symbiotic fungal responses to plant traits and soil factors is critical for optimizing urban tree “plant-soil-fungus” systems under pollution stress. To address this gap, we combined δ¹³C/δ¹⁵N isotope analysis and ITS sequencing for three common street trees in Beijing: Sophora japonica, Ginkgo biloba, and Populus tomentosa. In S. japonica, symbiotic fungal abundance was positively associated with leaf δ¹⁵N, indicating root exudate-mediated “plant-microbe” interactions during atmospheric NO_x assimilation. G. biloba, with weak NO_x assimilation, exhibited a negative correlation between fungal abundance and soil available N/P, suggesting mycorrhizal nutrient compensation under low fertility. P. tomentosa showed decreased fungal abundance with increasing soil N/P ratios and specific leaf area, reflecting carbon allocation trade-offs that limit mycorrhizal investment. These results demonstrate that symbiotic fungi respond to atmospheric and edaphic drivers in a tree species-dependent manner. Urban greening strategies should prioritize S. japonica for its NO_x mitigation potential and optimize fertilization for G. biloba (nutrient-sensitive fungi) and P. tomentosa (nutrient balance sensitivity). Strategic mixed planting of P. tomentosa with S. japonica could synergistically enhance ecosystem services through complementary resource acquisition patterns. This study provides mechanism-based strategies for optimizing urban tree management under atmospheric pollution stress. Full article

Vicia species are of great value in ecological restoration, soil improvement, and the development of a forage resource. In 2024, a novel pod disease affecting four-seeded vetches (Vicia tetrasperma) emerged in Rongchang District, China, leading to severe yield loss. After obtaining the main pathogenic strain, FVS1, through the tissue isolation method, which was verified according to Koch’s postulates, and by combining morphological characteristics with multigene phylogenetic analysis, FVS1 was identified as Fusarium proliferatum. The biological properties indicated that the most suitable culture medium of the fungus was oatmeal agar (OA), with the optimum growth temperature 25 °C and the lethal temperature being 35 °C. FVS1 exhibited insensitivity within a pH range of 7 to 9, as well as high adaptability to variations in light duration. To elucidate the physiological and biochemical changes in four-seeded vetches in response to FVS1 infection, non-targeted metabolomics analysis identified 379 differential metabolites, mainly comprising organic acids and derivatives, lipids and lipid-like molecules, and phenylpropanoids and polyketides. The results demonstrated that F. proliferatum primarily induced the disease by influencing alterations in the secondary metabolites associated with amino acid metabolism, lipid metabolism, and flavonoid biosynthesis. Four-seeded vetches improved tolerance to the fungus by accumulating histidine, aspartic acid, arginosuccinate, ethanolamine, glycerophosphocholine, naringenin, and catechin. Trichoderma harzianum (M3) had the best control effectiveness, and the inhibition rate was 60.68%. This study, for the first time, revealed that F. proliferatum caused a pod disease in four-seeded vetches. We analyzed the mechanism of plant–pathogen interaction and screened potential biocontrol strains, providing a theoretical basis for regional disease management. Full article

Maize production is increasingly challenged by climate change, which affects plant physiology, fungal colonization, and mycotoxin contamination. Aspergillus flavus, a saprophytic fungus, thrives in warm, dry conditions, leading to aflatoxin B1 (AFB1) accumulation, and posing significant food safety risks. Macro- and micro-climatic factors, including temperature, humidity, and precipitation, influence kernel development, leaf wetness duration, and mycotoxin biosynthesis. Nitrogen availability and irrigation play crucial roles in modulating plant responses to these stressors, affecting chlorophyll content, yield parameters, and fungal interactions. To investigate these interactions, a Completely Randomized Design (CRD) was employed from 2020 to 2022 to assess physiological changes in SY Orpheus maize hybrid under varying climatic conditions. Rising temperatures and declining relative humidity (RH) significantly reduced kernel number per ear length from 25.60 ± 0.34 in 2020 to 17.89 ± 0.39 in 2022 (p < 0.05), impacting yield. The AFB1 levels peaked in 2021 (156.88 ± 59.02 µg/kg), coinciding with lower humidity and increased fungal stress. Water availability improved kernel numbers and reduced AFB1 accumulation (p < 0.05) but did not significantly affect the total fungal load (p > 0.05). Nitrogen supplementation enhanced plant vigor, suppressed AFB1 biosynthesis, and influenced spectral indices. Potential confounding factors such as soil variability and microbial interactions may require further investigations. Full article

Strawberries are planted globally as an important crop. Fusarium oxysporum f. sp. fragariae (Fof), a haploid mitosporic, pathogenic fungus with obvious host specificity, is responsible for an economically devastating soil-borne disease seriously threatening strawberry. Fusarium oxysporum is distributed in soils worldwide and causes vascular wilt and root rot disease in over 100 plant species. However, the formae speciales of F. oxysporum commonly have a very narrow host range, often restricted to a single host plant species. We isolated and identified pathogenic F. oxysporum from diseased strawberry samples collected from different provinces in China. Further analysis showed that among the 55 F. oxysporum isolates, only 70.91% belonged to Fof, and the remaining 29.09% were named Fo. The mycelial growth of Fof was faster than that of Fo at 20, 30, and 35 °C. The sporulation ability of Fof was weaker than that of Fo, and Fof presented a significantly higher germination rate under high temperatures. Fof and Fo from strawberry were not pathogenic to tomato or cucumber plants, and Fof showed significantly higher pathogenicity on strawberry than Fo. To explore the pathogenic mechanism of Fof, we knocked out SIX10 in Fof. The mycelial growth rate of ΔFofSIX10 was significantly slower than that of the wild type, but there were no significant differences in spore production. The pathogenicity of ΔFofSIX10 to strawberry was significantly weakened, showing decreased severity of symptoms, indicated by root and crown rot, and wilt. Our research provides a basis for understanding the interaction between F. oxysporum and the host strawberry and the occurrence and management of Fusarium disease on strawberry. Full article

Zeolite, a microporous mineral with strong ion binding, can enhance nutrient availability and growth of plants, such as maize (Zea mays L.). Arbuscular mycorrhizal (AM) symbiosis has also been shown to enhance nutrient availability and growth of plants, including maize. However, the interaction between AM symbiosis and zeolite is poorly understood. In this study, the effect on growth of maize was examined following soil treatment with N-enriched (ZN+) zeolite, which could retain 19.68% N, or N-free zeolite (ZN−), compared to N-enriched or N-free vermiculite (VN+ and VN−). There was a 2.7-times increase in the growth of maize under ZN+ treatment compared to ZN−, indicating that N could be released from zeolite for plant growth, and a 3.8-times increase with ZN+ treatment compared to VN− or VN+, indicating that zeolite was more effective than vermiculite in releasing N for plant growth. Subsequently, ZN+ and ZN− treatments were examined with non-AM (M−) and AM (M+) treatments using Rhizophagus irregularis. ZN+ M+ treatment led to higher AM colonization and development compared to M+ ZN−treatment, indicating an interaction of AM in roots with N from zeolite. PCA revealed improvements in leaf N content, photosynthetic pigments, photosynthetic performance, and secondary metabolites with M+ ZN+ treatment, which was also observed in comparison to M−ZN+ and M− ZN−treatments, further supporting the benefit of combining N from zeolite with an AM fungus. The combination of N released from N-enriched zeolite and AM symbiosis offers a promising alternative to chemical fertilizers to improve maize growth. Full article

Branched broomrape (Phelipanche ramosa (L.) Pomel), an obligate parasitic weed with a wide host range, is known for its devasting effects on many crops worldwide. Soil fungi, notably Fusarium sp., are described as pathogenic to broomrape, while the hypothesis of the phytotoxicity of fusaric acid produced by F. verticillioides for parasitic weeds of the genus Orobanche has been proposed. Using image analysis and untargeted metabolomics, this study investigated fungal metabolites phytotoxic for P. ramosa and produced by the F. venenatum MIAE02836 strain, isolated from symptomatic broomrapes and identified as a promising candidate for broomrape biocontrol. Phytotoxicity tests of crude extracts from the fungus alone or in interaction with broomrape on P. ramosa microcalli and quantification of necrosis by image analysis confirmed the phytotoxic potential of F. venenatum MIAE02836 metabolites towards the early developmental stages of P. ramosa. Data analysis of a non-targeted metabolomics approach revealed numerous metabolites produced by F. venenatum MIAE02836. Four of them, accumulated during interaction with the parasitic plant, are known for their phytotoxic potential: maculosin, cyclo(Leu-Phe), phenylalanyl-D-histidine and anguidine. These results suggest that combining image acquisition of the microcalli screening test and untargeted metabolomic approach is an interesting and relevant method to characterize phytotoxic fungal metabolites. Full article

Moso bamboo (Phyllostachys edulis) forest is a key ecosystem and its soil microbial community plays a crucial role in maintaining the ecosystem’s functions, but it is very vulnerable to climate change. An altitude gradient can positively simulate environmental conditions caused by climate change, and hence, it provides an efficient means of investigating the response of soil microorganisms to such climatic changes. However, while previous research has largely concentrated on plant–soil–microorganism interactions across broad altitudinal ranges encompassing multiple vegetation types, studies examining these interactions within a single ecosystem across small altitudinal gradients remain scarce. This study took Moso bamboo forests at different altitudes in Wuyi Mountain, China, as the research object and used high-throughput sequencing technology to analyze the soil microbial community structure, aiming to elucidate the changes in soil microbial communities along the altitude gradient under the same vegetation type and its main environmental driving factors. This study found that the structure of bacterial community was notably different in Moso bamboo forests’ soil at varying altitudes, unlike the fungal community structure, which showed relatively less variance. Bacteria from Alphaproteobacteria phylum were the most dominant (14.71–22.91%), while Agaricomycetes was the most dominating fungus across all altitudinal gradients (18.29–30.80%). Fungal diversity was higher at 530 m and 850 m, while bacterial diversity was mainly concentrated at 850 m and 1100 m. Redundancy analysis showed that soil texture (sand and clay content) and available potassium content were the main environmental factors affecting fungal community structure, while clay content, pH, and available potassium content were the main drivers of bacterial community structure. This study demonstrates that the altitude gradient significantly affects the soil microbial community structure of Moso bamboo forest, and there are differences in the responses of different microbial groups to the altitude gradient. Soil properties are important environmental factors that shape microbial communities. The results of this study contribute to a deeper understanding of the impact of altitude gradient on the soil microbial community structure of Moso bamboo forests, thus providing support for sustainable management of Moso bamboo forests under climate change scenarios. Full article

Mal secco is a vascular disease of citrus caused by the mitosporic fungus Plenodomus tracheiphilus. Soil containing infected plant material constitutes an inoculum source for root infections. In this study, the soil bacterial and fungal communities of five lemon orchards located in Syracuse Province (Sicily, Italy) affected by mal secco were analyzed. Soil samples were collected under lemon tree canopies and subjected to total genomic DNA extraction. The fungal DNA was detected through qPCR in all orchards, with variable concentrations. Bacterial and fungal communities were profiled using 16S and ITS amplicon-based high-throughput sequencing, respectively. According to our results, the relative abundances of the most represented bacterial phyla (e.g., Proteobacteria, Actinobacteriota, Acidobacteriota) changed across the orchards, while in the fungal community, the phylum Ascomycota was dominant, with Basidiomycota and Mortierellomycota abundances fluctuating. On the whole, β diversity analysis showed significant variation in the composition of the soil microbial communities across the orchards. This result was confirmed by the analysis of the core community (taxa present at ≥ 75% of total samples), where putative beneficial bacteria resulted in significantly enriched fungus-infected soil samples, suggesting complex microbial interactions. Our findings shed light on the composition and diversity of the soil microbiome in lemon orchards with the occurrence of mal secco infections. Full article

To optimize the application of plant growth-promoting rhizobacteria (PGPR) in field trials, tracking methods are needed to assess their shelf life and to determine the elements affecting their effectiveness and their interactions with plants and native soil microbiota. This work developed a real-time PCR (qtPCR) method which traces and quantifies bacteria when added as microbial consortia, including five PGPR species: Burkholderia ambifaria, Bacillus amyloliquefaciens, Azotobacter chroococcum, Pseudomonas fluorescens, and Rahnella aquatilis. Through a literature search and in silico sequence analyses, a set of primer pairs which selectively tag three bacterial species (B. ambifaria, B. amyloliquefaciens and R. aquatilis) was retrieved. The primers were used to trace these microbial species in a field trial in which the consortium was tested as a biostimulant on two wheat varieties, in combination with biochar and the mycorrhizal fungus Rhizophagus intraradices. The qtPCR assay demonstrated that the targeted bacteria had colonized and grown into the soil, reaching a maximum of growth between 15 and 20 days after inoculum. The results also showed biochar had a positive effect on PGPR growth. In conclusion, qtPCR was once more an effective method to trace the fate of supplied bacterial species in the consortium when used as a cargo system for their delivery. Full article

In this review, an overview was given of the mutual interactions between nematodes and fungi of the genus Trichoderma sp. due to the potential of these fungi to protect plant roots from plant-parasitic nematodes on the one hand and the influence of nematodes (fungivores) on the efficacy of the fungus on the other. In addition, an overview of the advantages of Trichoderma sp. for agricultural production was given. The basis of sustainable agricultural production is the healthy functioning of the soil ecosystem. The diversity of organisms—bacteria, protozoa, algae, metazoans (nematodes) and fungi—improves the quality and performance of the soil by maintaining biological productivity. Root exudates in the rhizosphere support microbial communities that play a key role in regulating the dynamics of organic matter decomposition and the availability of plant nutrients. The microbial activity of organisms in the soil is interconnected and interacts to form a soil food web that reflects the condition, function and health of the soil. The energy in food webs flows through trophic chains of consumers, which are divided into energy channels. Root, bacterial and fungal channels increase soil biomass, carbon (C) and energy flow through the soil food web. The structure of the nematode community is an effective tool for the biological assessment of soil quality. This is due to a number of characteristics that nematodes have, including the following: a great diversity of species, the possibility of subdivision according to different criteria such as trophic groups and c-p groups, the duration of reproduction, the ease of sampling, the identification of genera and preservation, etc. Nematodes are involved in various ecological functions in the soil, of which the interaction between them and fungi is based on antagonism or mutualism, which is the basis for a better understanding of their impact on the ecosystem. Fungi of the genus Trichoderma sp. are successful colonizers of all habitats, secondary opportunists and fast growing. Full article

Arbuscular mycorrhizal (AM) fungi engage in symbiosis with more than 80% of terrestrial plants, enlarging root phosphorus (P) absorption volume by producing extensive extraradical hyphae (ERH) in the soil. In addition, AM fungi recruit and cooperate with soil bacteria to enhance soil organic P mobilization and improve fungal and plant fitness through hyphal exudates. However, the role of the dominant compounds in the hyphal exudates in enhancing organic P mobilization in the mycorrhizal pathway is still not well understood. In this study, we added sugars, i.e., glucose, fructose, and trehalose, which are detected in the hyphal exudates, to the hyphal compartments (HCs) that allowed the ERH of the AM fungus to grow or not. The results showed that in AM fungus-inoculated pots, adding three sugars at a concentration of 2 mmol C kg⁻¹ soil significantly increased the phosphatase activity and facilitated the mobilization of organic P in the HCs. The addition of fructose at a concentration of 2 mmol C kg⁻¹ soil was the most efficient in increasing the phosphatase activity and enhancing organic P mobilization. The released inorganic P was then absorbed by the ERH of the AM fungus. The enhanced mobilization of organic P was correlated with the increase in phoD gene number and the changing bacterial community in the presence of fungal hyphae. The sugar addition enriched the relative abundance of some bacterial taxa, e.g., Betaproteobacteriales. Our study suggested that the addition of the sugars by mycorrhizae could be a pivotal strategy in managing P uptake in agricultural production, potentially directing future practices to optimize plant–fungi–bacteria interactions for improved P use efficiency. Full article

Plasmodiophora brassicae (P. brassicae) is a soil-born pathogen worldwide and can infect most cruciferous plants, which causes great yield decline and economic losses. It is not well known how microbial diversity and community composition change during P. brassicae infecting plant roots. Here, we employed a resistant and a susceptible pakchoi cultivar with and without inoculation with P. brassicae to analyze bacterial and fungal diversity using 16S rRNA V3-V4 and ITS_V1 regions, respectively. 16S rRNA V3-V4 and ITS_V1 regions were amplified and sequenced separately. Results revealed that both fungal and bacterial diversity increased, and composition was changed in the rhizosphere soil of the susceptible pakchoi compared with the resistant cultivar. In the four groups of R_mock, S_mock, R_10d, and S_10d, the most relatively abundant bacterium and fungus was Proteobacteria, accounting for 61.92%, 58.17%, 48.64%, and 50.00%, respectively, and Ascomycota, accounting for 75.11%, 63.69%, 72.10%, and 90.31%, respectively. A total of 9488 and 11,914 bacteria were observed uniquely in the rhizosphere soil of resistant and susceptible pakchoi, respectively, while only 80 and 103 fungi were observed uniquely in the correlated soil. LefSe analysis showed that 107 and 49 differentially abundant taxa were observed in bacteria and fungi. Overall, we concluded that different pakchoi cultivars affect microbial diversity and community composition, and microorganisms prefer to gather around the rhizosphere of susceptible pakchoi. These findings provide a new insight into plant–microorganism interactions. Full article

The entomopathogenic endophytic fungus Beauveria bassiana can colonize plants resulting in growth promotion and protection against phytopathogenic microorganisms. However, physiological changes in potato plants (Solanum tuberosum) during this interaction are poorly understood. In the present work, gas chromatography–mass spectrometry and high-performance liquid chromatography were used to analyze sterol, fatty acid, and phenolic acid concentrations in potato plants inoculated with B. bassiana conidia in soil. We showed an increase in amounts of stigmasterol, minor sterol compounds, and some hydroxy fatty acids in leaves after the fungal treatment. Moreover, levels of hydroxycinnamic acids, especially chlorogenic acid, were elevated in roots following the B. bassiana inoculation. We propose that these changes could have been caused by oxidative reactions, and the alterations may have resulted in growth-stimulatory and protective effects of B. bassiana on the plants. Full article