Search Results (708)

The lotus–fish co-culture (LFC) system leverages plant–fish symbiosis to optimize aqua-culture environments, enhancing both economic and ecological yields. However, the eco-logical mechanisms of microbial communities in LFC systems remain poorly understood, particularly regarding the functional roles of fungi, archaea, and viruses. This study compared microbiota (viruses, archaea, fungi) in water, sediment, and fish (crucian carp) gut of LFC and intensive pond culture (IPC) systems using integrated metagenomic and environmental analyses. Results demonstrated that LFC significantly reduced concentrations of total nitrogen, total phosphorus, and nitrite nitrogen and chemical oxygen demand in water, and organic matter and total nitrogen in sediment compared to IPC. Community diversity analysis, LefSe, and KEGG annotation revealed suppressed viral diversity in LFC, yet increased complexity and stability of intestinal virus communities compared to IPC. Archaeal and functional analyses revealed significantly enhanced ammonia oxidation and OM decomposition in LFC versus IPC, promoting methane metabolism equilibrium and sediment organic matter decomposition. Moreover, crucian carp intestines in LFC harbored abundant Methanobacteria, which contributed to maintaining a low hydrogen partial pressure, suppressing facultative anaerobes and reducing intestinal infection risk. The abundance of fungi in sediment and crucian carp intestine in LFC was significantly higher than that in IPC, showing higher ecological self-purification ability and sustainability potential in LFC. Collectively, LFC's optimized archaeal–fungal networks strengthened host immunity and environmental resilience, while viral community suppression reduced pathogen risks. These findings elucidate microbiome-driven mechanisms underlying LFC’s ecological advantages, providing a framework for designing sustainable aquaculture systems through microbial community modulation. Full article

Phytopathogenic fungi secrete numerous effector proteins to disrupt plant defenses. At present, their sequence–structure–function relationships remain poorly understood owing to their diversity. Comprehensive understanding of conserved effectors is necessary to elucidate the molecular relationship between fungi and plants. To fill this research gap, we investigated the Colletotrichum higginsianum effector candidate (ChEC)-88 specifically expressed during infection. Notably, similar to the biotrophy-associated secreted protein 3 (BAS3) from Pyricularia oryzae, ChEC88 inhibited plant cell death caused by necrosis- and ethylene-inducing peptide 1-like protein (NLP1). Nuclear magnetic resonance analysis results revealed that ChEC88 adopted a novel pseudo two-fold symmetrical three-dimensional structure. Homology modeling suggested that BAS3 exhibited a ChEC88-like conformation despite sharing less than 50% sequence identity. Through PSI-BLAST searches, we found that ChEC88 homologs were conserved in various hemibiotrophic phytopathogenic fungi, including Colletotrichum, P. oryzae, and Fusarium species. Functional assays demonstrated that all of the representative homologs suppressed NLP1-induced plant cell death. Mutation experiments identified the residues critical for ChEC88 function. Overall, our findings suggest that hemibiotrophic phytopathogenic fungi share a conserved immune-suppression strategy mediated by ChEC88-like proteins and that such effectors possibly originated from a common ancestral lineage of phytopathogenic fungi. Full article

Powdery mildew, predominantly caused by Podosphaera xanthii and Golovinomyces orontii, presents a major constraint to cucurbitaceous crop production worldwide. Despite intensive research, the complex interplay between pathogen virulence factors and host immune responses remains only partially understood. Recent advances in genomics, transcriptomics, and gene editing technologies have shed light on key molecular mechanisms underlying host susceptibility, quantitative resistance, and potential durable control strategies. In this review, we summarize the biology of powdery mildew fungi infecting cucurbits, the latest findings on pathogen effectors, plant defense signaling, and the genetic basis of resistance. We also discuss novel breeding and biotechnological approaches for durable powdery mildew resistance and outline future directions for integrative disease management strategies. Full article

This study investigated the diversity and distribution of phytopathogenic fungi associated with goosegrass (Eleusine indica), an aggressive weed in agriculture, and bioprospected fungi isolates with potential for biological control of this species. Samples showing disease symptoms were collected from Goias, Minas Gerais, and São Paulo (Brazilian states), resulting in 88 isolates, of which 50 were phytopathogenic to E. indica. A total of 26 isolates were considered more aggressive based on visual analysis and were preliminarily identified at the genus level, with an emphasis on Bipolaris, Fusarium, Curvularia, Exserohilum, and Alternaria. The influence of climatic factors, such as sunny days (UV radiation), temperature, and precipitation on fungal occurrence was analyzed. These climatic factors are critical to the presence of fungi, providing insights into their potential as biological control agents and guiding future surveys of specific genera. The number of sunny days during surveys influenced the occurrence of fungi associated with E. indica, depending on the genera of the fungi. In addition, precipitation was also a determining factor for a higher incidence of fungal isolates during periods of increased rainfall, suggesting a positive relationship between relative humidity and the dispersal or infection of phytopathogenic fungi. New tests will be conducted to confirm the potential of the identified plant phytopathogenic fungi as biological control agents against E. indica. Full article

One of the important traits of many plant growth-promoting rhizobacteria (PGPR) is the biocontrol of phytopathogens. Some PGPR metabolize phytohormone abscisic acid (ABA); however, the role of this trait in plant–microbe interactions is scarcely understood. Phytopathogenic fungi produce ABA and use this property as a negative regulator of plant resistance. Therefore, interactions between ABA-producing necrotrophic phytopathogen Botrytis sp. BA3 with ABA-metabolizing rhizobacterium Rhodococcus sp. P1Y were studied in a batch culture and in gnotobiotic hydroponics with sunflower seedlings. Rhizobacterium P1Y possessed no antifungal activity against BA3 and metabolized ABA, which was synthesized by BA3 in vitro and in associations with sunflower plants infected with this fungus. Inoculation with BA3 and the application of exogenous ABA increased the root ABA concentration and inhibited root and shoot growth, suggesting the involvement of this phytohormone in the pathogenesis process. Strain P1Y eliminated negative effects of BA3 and exogenous ABA on root ABA concentration and plant growth. Both microorganisms significantly modulated the hormonal status of plants, affecting indole-3-acetic, salicylic, jasmonic and gibberellic acids, as well as cytokinins concentrations in sunflower roots and/or shoots. The hormonal effects were complex and could be due to the production of phytohormones by microorganisms, changes in ABA concentrations and multiple levels of crosstalk in hormone networks regulating plant defense. The results suggest the counteraction of rhizobacteria to ABA-producing phytopathogenic fungi through the metabolism of fungal ABA. This expands our understanding of the mechanisms related to the biocontrol of phytopathogens by PGPR. Full article

Legumes are among the most important crops globally, serving as a major food source for protein and oil. In tropical regions, the cultivation of legumes has expanded significantly due to the increasing demand for food, plant-based products, and sustainable agriculture practices. However, tropical environments pose unique challenges, including high temperatures, erratic rainfall, soil infertility, and a high incidence of pests and diseases. Indeed, legumes are vulnerable to infections caused by bacteria, fungi, oomycetes, viruses, and nematodes. This review highlights the importance of legumes in tropical farming and discusses major diseases affecting productivity and their impact on the economy, environment, and lives of smallholder legume farmers. We emphasize the use of legume genetic resources and breeding, and biotechnology innovations to foster resistance and address the challenges posed by pathogens in legumes. However, an integrated approach that includes other cultivation techniques (e.g., crop rotation, rational fertilization, deep plowing) remains important for the prevention and control of diseases in legume crops. Finally, we highlight the contributions of plant genetic resources to smallholder resilience and food security. Full article

Oregano (Origanum vulgare) cultivation is of great economic importance in Peru. Tacna stands out as its main producer. However, the presence of phytopathogenic fungi represents a challenge for its production. This study aimed to characterize both the morphological and molecular levels of the causal agent of crown and root rot in a crop field in the Camilaca district, Candarave, Tacna. To this end, systematic sampling was carried out using the five-gold method, collecting plants with typical symptoms. Fungi were isolated from diseased roots and characterized using macroscopic and microscopic morphological analysis as well as sequencing and multilocus phylogenetic analysis (ITS, 28S, HIS3, TEF1, TUB2). In addition, pathogenicity tests were performed on healthy plants to confirm the infectivity of the isolates. The results demonstrated that root rot was caused by a complex of phytopathogenic fungi through phylogenetic analysis of Dactylonectria torresensis, Fusarium oxysporum, F. iranicum, and F. redolens. These findings represent the first report of these species as causal agents of oregano root rot in Peru, highlighting the need for integrated management strategies that reduce the economic impact of these diseases and contribute to the sustainability of the crop in key producing regions such as Tacna. Full article

Almond decline and dieback have become significant challenges in newly established orchards, with symptoms including internal necrosis, canker, and external gummosis. This work aims to explore the potential fungal and bacterial causative agents through metabarcoding and traditional culture plate isolation across six almond cultivars. Our results emphasize the multifactorial nature of almond decline and dieback, with possible co-infections by opportunistic fungi and bacteria playing a central role. Classical isolation identified 47 fungal species or genera, including Diaporthe amygdali, Diplodia corticola, Phytophthora sp., and several Fusarium species. Almond metabarcoding revealed a more diverse microbial community, highlighting the prevalence of soilborne pathogens such as Neocosmospora rubicola, Dactylonectria estremocensis, and Plectosphaerella niemeijerarum. Soil metabarcoding suggested that these pathogens likely originate from nursery substrates or soils shared with other crops, such as olives and vineyards, that serve as a source of inoculum. ‘Soleta’ generally presented lower richness when compared to the other tested cultivars, suggesting a higher degree of biotic stress and decreased plant resilience. This study highlights the value of integrating NGS approaches to comprehensively study complex diseases and the need for further research on pathogen interactions and cultivar susceptibility for the future development of new sustainable, targeted management strategies in almond orchards. Full article

Polyphenols are structurally diverse plant metabolites that have attracted significant interest. Their compositions are versatile, depending on their structures, including the number of rings in the polyphenol composition. Based on these attributes, polyphenols can be classified as flavanols, anthocyanins, flavones, phenolic acids, stilbenes, and lignans. Polyphenols mainly possess inhibition of viral replication, interference with viral protein synthesis, and modulation of immune responses, providing significant antiviral effects against several viruses, including herpes simplex virus, hepatitis C virus, and influenza. They are crucial for medical compounds in diverse, versatile treatments, namely in diabetes, cardiovascular disorders, cancer, and neurodegenerative problems. Plants are the primary source of bioactive molecules, which are valued for their anti-inflammatory, antioxidant, anticancer, and antiviral activities. Especially, polyphenols are extracted as the most abundant bioactive compounds of plants. Moreover, viral infections are one of the major factors in illnesses and diseases, along with bacteria and fungi. Numerous in vitro and in vivo studies report antiviral activity against SARS-CoV-2, Mayaro virus, dengue virus, herpesvirus, and influenza A virus, though clinical validation remains limited. Additionally, inhibition of viral entry, interference with viral replication, modulation of host immune response, and direct virucidal effects were examined. Full article

Arundo donax L. has been introduced in markets worldwide due to its economic value. However, it is listed in the world’s 100 worst alien invasive species because it easily escapes from cultivation, and forms dense monospecific stands in riparian areas, agricultural areas, and grassland areas along roadsides, including in protected areas. This species grows rapidly and produces large amounts of biomass due to its high photosynthetic ability. It spreads asexually through ramets, in addition to stem and rhizome fragments. Wildfires, flooding, and human activity promote its distribution and domination. It can adapt to various habitats and tolerate various adverse environmental conditions, such as cold temperatures, drought, flooding, and high salinity. A. donax exhibits defense mechanisms against biotic stressors, including herbivores and pathogens. It produces indole alkaloids, such as bufotenidine and gramine, as well as other alkaloids that are toxic to herbivorous mammals, insects, parasitic nematodes, and pathogenic fungi and oomycetes. A. donax accumulates high concentrations of phytoliths, which also protect against pathogen infection and herbivory. Only a few herbivores and pathogens have been reported to significantly damage A. donax growth and populations. Additionally, A. donax exhibits allelopathic activity against competing plant species, though the allelochemicals involved have yet to be identified. These characteristics may contribute to its infestation, survival, and population expansion in new habitats as an invasive plant species. Dense monospecific stands of A. donax alter ecosystem structures and functions. These stands impact abiotic processes in ecosystems by reducing water availability, and increasing the risk of erosion, flooding, and intense fires. The stands also negatively affect biotic processes by reducing plant diversity and richness, as well as the fitness of habitats for invertebrates and vertebrates. Eradicating A. donax from a habitat requires an ongoing, long-term integrated management approach based on an understanding of its invasive mechanisms. Human activity has also contributed to the spread of A. donax populations. There is an urgent need to address its invasive traits. This is the first review focusing on the invasive mechanisms of this plant in terms of adaptation to abiotic and biotic stressors, particularly physiological adaptation. Full article

Fungal melanin plays a vital role in the survival, reproduction, infection, and environmental adaptation of plant pathogenic fungi. To develop innovative strategies for managing plant fungal diseases, comprehensive investigations into melanin are imperative. Such research is fundamental to elucidating the mechanistic basis of fungal pathogenesis and holds promise for the design of targeted interventions against melanin-mediated virulence determinants. This review systematically elaborates on the classification of fungal melanin in plant pathogens, provides a detailed analysis of the biosynthetic processes of 3,4-dihydroxyphenylalanine (DOPA) and 1,8-dihydroxynaphthalene melanin (DHN melanins), and reveals the catalytic functions and regulatory mechanisms of key enzymes within these pathways. Melanin modulates fungal virulence by influencing appressorial integrity and turgor pressure formation, thereby participating in the host infection process and the formation of overwintering sclerotia. Melanin provides stress resistance by protecting against extreme environmental factors, including UV radiation and high temperatures. It also has the capacity to absorb heavy metals, which increases pathogen survival under adverse conditions. Furthermore, the review also explores the mechanisms of action of melanin inhibitors that target plant pathogenic fungi, providing a theoretical foundation for developing efficient and environmentally friendly antifungal medications. The complex biosynthesis pathways and diverse biological functions of fungal melanin highlight its significant theoretical and practical importance for elucidating pathogenic mechanisms and formulating scientific control strategies. Full article

Phytoplasmas are wall-less, phloem-restricted bacteria responsible for numerous significant plant diseases worldwide. An increasing body of evidence indicates that phytoplasmas can coexist with other pathogens in mixed infections, including various 16Sr group phytoplasmas, ‘Candidatus Liberibacter’ species, viruses, spiroplasmas, fungi, and other difficult-to-culture phloem-limited bacteria. These interactions challenge established views regarding the causes, detection, and management of plant diseases. This review consolidates existing knowledge on the diversity and epidemiology of phytoplasma-related mixed infections, with a particular emphasis on documented co-infections across various host plants and regions, especially in tropical and subtropical areas. Mixed infections affect disease severity, symptom expression, vector behavior, and pathogen dissemination, highlighting the limitations of pathogen-specific diagnostic and control strategies. The necessity for tools to detect multiple pathogens, enhanced understanding of pathogen–pathogen and host–pathogen interactions, and comprehensive surveillance systems is emphasized. Ultimately, breeding for resistance must consider the complexities of natural co-infections to ensure effective protection of crops. Addressing the challenges presented by phytoplasma-related mixed infections is crucial for developing resilient and sustainable plant health strategies in the face of increasing ecological and agricultural pressures. Full article

The major objective was to investigate the protective capabilities of endophytic bacterial strains isolated from a number of medicinal plant species towards Aspergillus spp. secured from the internal tissues of fungi-infected peanuts. Among 32 fungal isolates surveyed for mycotoxin production in various culture media (PDA, RBCA, YES, CA), 10 isolates qualitatively producing AFB₁, besides 10 OTA-producers, were assayed by HPLC for quantitative toxin production. Aspergillus spp. isolate Be 13 produced an extraordinary quantity of 1859.18 μg mL⁻¹ AFB₁, against the lowest toxin level of 280.40 μg mL⁻¹ produced by the fungus isolate IS 4. The estimated amounts of OTA were considerably lower and fell in the range 0.88–6.00 μg mL⁻¹; isolate Sa 1 was superior, while isolate Be 7 seemed inferior. Based on ITS gene sequencing, the highly toxigenic Aspergillus spp. isolates Be 13 and Sa 1 matched the description of A. novoparasiticus and A. ochraceus, respectively, ochraceus, respectively, which are present in GenBank with identity exceeding 99%. According to 16S rRNA gene sequencing, these antagonists labeled Ar6, Ma27 and So34 showed the typical characteristics of Pseudomonas aeruginosa, Bacillus subtilis and Bacillus velezensis, respectively, with similarity percentages of 99–100. The plant growth-promoting activity measurements of the identified endophytes indicated the production of 16.96–80.00 μg/100 mL culture medium of IAA. Phosphate-solubilizing capacity varied among endophytes from 2.50 to 21.38 μg/100 mL. The polysaccharide production pool of bacterial strains ranged between 2.74 and 6.57 mg mL⁻¹. P. aeruginosa Ar6 and B. velezensis successfully produced HCN, but B. subtilis failed. The in vitro mycotoxin biodegradation potential of tested bacterial endophytes indicated the superiority of B. velezensis in degrading both mycotoxins (AFB₁-OTA) with average percentage of 88.7; B. subtilis ranked thereafter (85.6%). The 30-day old peanut (cv. Giza 6) seedlings grown in gnotobiotic system severely injured due to infection with AFB₁/OTA-producing fungi, an effect expressed in significant reductions in shoot and root growth traits. Simultaneous treatment with the endophytic antagonists greatly diminished the harmful impact of the pathogens; B. velezensis was the pioneer, not P. aeruginosa Ar6. In conclusion, these findings proved that several endophytic bacterial species have the potential as alternative tools to chemical fungicides for protecting agricultural commodities against mycotoxin-producing fungi. Full article

Grapevine (Vitis vinifera) is a key crop in Mediterranean agriculture, now increasingly threatened by Xylella fastidiosa subsp. Fastidiosa (Xff), the causal agent of Pierce’s disease. This study investigated: (1) the diversity of culturable fungal endophytes in the xylem sap of naturally Xff-infected grapevines, and (2) the interaction between Xff and the pathogenic fungus Sclerotinia sclerotiorum identified in the sap. The xylem sap was collected from Cabernet Sauvignon vines in Mallorca, Spain, and fungal communities were characterized using culture-dependent methods. Both beneficial fungi (e.g., Aureobasidium pullulans, Rhodotorula mucilaginosa) and pathogenic species (e.g., S. sclerotiorum, Cladosporium sp., Alternaria alternata, and the Phoma complex) were isolated from both Xff-positive and Xff-negative plants, indicating similar community profiles. Although limited by small sample size, these findings offer preliminary evidence of complex ecological interactions between Xff and the xylem-associated mycobiota, with potential implications for grapevine health and disease development under varying environmental and management conditions. Further experiments under controlled conditions revealed that grapevines co-inoculated with Xff and S. sclerotiorum showed increased disease severity, suggesting a synergistic interaction. These preliminary results highlight the complex interplay between Xff and the fungal endophytic microbiome, which may modulate grapevine susceptibility depending on environmental and management conditions. Full article

Arbuscular mycorrhizae fungi (AMF) plays an important role in plants’ response to environmental stress, and the main environmental stress encountered in grape production is high temperature stress. This study aims to inoculate Funneliformis mosseae (A type of AMF) on grapes and investigate their tolerance to high temperature stress after inoculation. The results showed that AMF could infect grape roots, and the mycorrhizal infection rate was 20.78%. After inoculation with AMF, the growth of grape plants was significantly better than that in the non-inoculation group. Compared with the uninoculated group, the net photosynthetic rate, transpiration rate and stomatal conductance were higher in the AMF group, and the intercellular CO₂ concentration was lower. After high temperature treatment, there was no significant difference in the content of hydrogen peroxide (H₂O₂) in grape leaves between the two experimental groups at each time, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and other enzymes showed great differences, especially after high temperature treatment for 6 h. The activities of SOD, POD and CAT in AMF group were significantly higher than those in uninoculated group. The content of malondialdehyde (MDA) in grape leaves of the two experimental groups had no significant difference between 0 h and 3 h after high temperature treatment, and the MDA content in the AMF group was significantly lower than that in the uninoculated group after 6 h of high temperature treatment. The contents of soluble sugar and soluble protein in the AMF group were higher than those in the uninoculated group at all time periods, especially after 6 h of high temperature treatment. In addition, we found that VvHSP70, VvHSP17.9, VvGLOS1, VvHSFA2 genes all responded to high temperature stress, but there was no significant difference between the AMF group and the uninoculated group. It can be seen from the above that AMF can significantly enhance the adaptability of grape plants to high temperature stress by improving photosynthetic efficiency, antioxidant enzyme activity, soluble sugar and soluble protein content, and reduce Malondialdehyde (MDA) content, which provides guidance and theoretical basis for grape production. Full article