Search Results (891)

The utilization of fast-growing, economically valuable woody plants with strong stress resistance, such as poplar and willow, to revegetate severely metal-contaminated mine tailings not only offers a productive and profitable use of abandoned polluted soil resources but also facilitates the phytoremediation of these polluted soils. This study examines the diversity and functional roles of endophytic fungi naturally colonizing the roots of an artificially established Populus yunnanensis forest and the naturally reclaimed pioneer species Coriaria sinica on an abandoned tailing dam in southwest China. Culture-independent analyses revealed that the root systems of both plant species were abundantly colonized by arbuscular mycorrhizal fungi and endophytic fungi, forming rich and diverse endophytic fungal communities predominantly represented by the genera Ilyonectria, Tetracladium, Auricularia, and unclassified members of Helotiales. However, the composition of root endophytic fungal communities differed significantly between the two plant species. Using a culture-dependent approach, a total of 192 culturable endophytic fungal strains were isolated from the roots. The dominant genera included Cadophora, Cladosporium, Cyphellophora, and Paraphoma, most of which were previously identified as dark septate endophytes (DSE). Six representative DSE strains were selected for further study, and significant cadmium tolerance and various plant growth-promoting traits were observed, including the solubilization of insoluble inorganic and organic phosphorus, indole-3-acetic acid (IAA) production, and siderophore synthesis. In greenhouse experiments, inoculating two DSE strains mitigated the inhibitory effects of metal-polluted tailing soil on the growth of P. yunnanensis. This was achieved by reducing heavy metal uptake in roots and limiting metal translocation to the above-ground tissues, thereby promoting plant growth and adaptability. Our findings suggest that as plants reclaim metal-polluted tailings, root-associated endophytic fungal communities also undergo natural succession, playing a critical role in enhancing the host plant’s tolerance to stress. Therefore, these restored root-associated fungi, particularly DSE, are essential functional components of the root systems in plants used for tailing reclamation. Full article

Cotton (Gossypium spp.) is the most important fibre crop worldwide. Black root rot and Fusarium wilt are two major diseases of cotton caused by soil-borne Berkeleyomyces rouxiae and Fusarium oxysporum f. sp. vasinfectum (Fov), respectively. Phenotyping plant symptoms caused by soil-borne pathogens has always been a challenge. To increase the uniformity of infection, we adapted a seedling screening method that directly uses liquid cultures to inoculate the plant roots and the soil. Four isolates, each of B. rouxiae and Fov, were collected from cotton fields in Australia and were characterised for virulence on cotton under controlled plant growth conditions. While the identities of all four B. rouxiae isolates were confirmed by multilocus sequencing, only two of them were found to be pathogenic on cotton, suggesting variability in the ability of isolates of this species to cause disease. The four Fov isolates were phylogenetically clustered together with the other Australian Fov isolates and displayed both external and internal symptoms characteristic of Fusarium wilt on cotton plants. Furthermore, the isolates appeared to induce varied levels of plant disease severity indicating differences in their virulence on cotton. To contrast the virulence of the Fov isolates, four putatively non-pathogenic Fusarium oxysporum (Fo) isolates collected from cotton seedlings exhibiting atypical wilt symptoms were assessed for their ability to colonise cotton host. Despite the absence of Secreted in Xylem genes (SIX6, SIX11, SIX13 and SIX14) characteristic of Fov, all four Fo isolates retained the ability to colonise cotton and induce wilt symptoms. This suggests that slightly virulent strains of Fo may contribute to the overall occurrence of Fusarium wilt in cotton fields. Findings from this study will allow better distinction to be made between plant pathogens and endophytes and allow fungal effectors underpinning pathogenicity to be explored. Full article

A substrate-based production system is a simple and low-cost method for arbuscular mycorrhizal (AM) fungal inoculum production. However, it is time-consuming and typically yields low numbers of AM fungal spores due to several factors affecting plant growth efficiency. Our study investigated the use of light-emitting diode (LED) technology to expedite AM fungal spore production in planta. We performed experiments with Rhizophagus irregularis inoculated in maize (Zea mays L.), contrasting LED light with greenhouse (GH) conditions. Our results exhibited a significant improvement in AM fungal colonization and spore production, as well as a reduction in the production period from 120 to 90 days under the LED light condition. This was achieved using a red-and-blue light ratio of 60:40 with a total light intensity of 300 µmol m⁻² s⁻¹. The LED light treatments improved maize growth by increasing nitrogen (N) and phosphorus (P) concentrations in shoots and roots, respectively. Our gene expression analyses revealed that in AMF-inoculated plants, genes related to photosynthesis were significantly upregulated under LED light compared to the GH condition. Moreover, LED increased the expression of marker genes linked to the AM fungi-related cell cycle, indicating enhanced AM fungal growth during symbiosis. These findings advance our comprehension of LED applications in agriculture, offering promising prospects for acceleration of AM fungal spore production. Full article

In this study, we decided to test the hypothesis that the fungal biostarter M. flavus used during a 21-day beef dry-aging process significantly impacts the composition of other microorganisms, the profile of volatile compounds, meat hardness characteristics, and, consequently, the sensory quality. The experiments were performed on samples derived from animals crossbred between Holstein–Fresian cows and meat breed bulls. Two groups of samples were studied, including the control group, without biostarter, and a group inoculated with the M. flavus biostarter. Both sample groups were seasoned for 21 days in the dry-aging fridge. The physicochemical parameters (pH, color parameters), the chemical composition of muscle, the determination of the shear force, the profile of volatile compounds (VOCs), and the sensory quality were evaluated after aging. During this study, classical microbiological methods were used to investigate the influence of fungal biostarters on the growth and survival of bacteria and other fungi (e.g., yeasts) during the dry-aging process of beef (DAB). The M. flavus biostarter improved the sensory quality of DAB, allowing high sensory quality to be achieved after just 21 days. This is likely due to the diverse VOCs produced by the fungus, including 1-tetradecanol, 2-nonenal, trans-2-undecenoic acid, and the following esters: formic acid hexyl ester, 10-undecenoic acid methyl ester, and 4-methylpentanoic acid methyl ester. The presence of the biostarter had no significant effect on the number of the bacteria or the survivability of the L. monocytogenes on the meat’s surface in laboratory conditions. Full article

Soil salinization during wheat cultivation considerably diminishes soil fertility and impedes wheat growth, primarily due to rhizosphere microbial community changes. Our study investigates the application of Bacillus subtilis YJ-15, a strain isolated from the rhizosphere of wheat cultivated in salinized soil, as a soil remediation agent. This strain has demonstrated significant salt tolerance, disease suppression capabilities, and growth-promoting attributes in previous studies. The wheat rhizosphere was examined to assess the impact of Bacillus subtilis YJ-15 on microbial community composition and soil fertility. Fertility of soil in saline soil was significantly increased by inoculating wheat with YJ-15. The microbial community structure within the wheat rhizosphere inoculated with Bacillus subtilis YJ-15 was analyzed through sequencing on the Illumina MiSeq platform. Phyla Proteobacteria and Acidobacteria were identified as the dominant bacteria. Basidiomycota, Mortierellomycota, and Ascomycota dominated the fungal phyla. Among the bacterial genera, Pseudomonas, Arthrobacter, and Bacillus were predominant. The predominant fungal genera included Alternaria, Cephalotrichum, Mortierella, and Chaetomium. A significant increase in Gaiella and Haliangium levels was observed in the YJ group compared to the control group. Additionally, the fungal genera Epicoccum, Sporidiobolus, and Lecythophora have significantly increased in YJ abundance. One of the potential benefits of Bacillus subtilis YJ-15 in the cultivation of wheat on salinized land is its ability to enhance the rhizosphere microbial community structure and improve soil fertility. Full article

The long history and extensive use of antibiotics have caused resistant bacterial pathogens to emerge, increasing mortality and morbidity. The current study was designed to see the prevalence of aerobic bacterial isolates with their antimicrobial resistance pattern from out- and inpatients requested for wound or pus culture. Retrospective study conducted at a tertiary care hospital in central Riyadh from January 2023 to December 2023. Samples were collected and inoculated onto the appropriate media following standard guidelines. Bacterial pathogens were identified by the Vitek2 compact system. Antimicrobial susceptibility was tested using the Kirby–Bauer disk diffusion method as well as by MIC determination through the Vitek2 compact. A total of 1186 subjects were included in the study with a bacterial isolation rate of 691 (58.3%). Out of these, 155 positive cultures had incomplete information or anaerobic or fungal growth and were excluded from the study. With a slight female predominance (54.9%), the majority of subjects (72.2%) were outpatients, and over half of the isolates (55.2%) were Gram-positive. The most common isolate was Staphylococcus spp. (44.4%), followed by E. coli (13.6%) and P. aeruginosa (12.9%). The highest resistance was reported against penicillin followed by fusidic acid against Gram-positive bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 40.5% of Staphylococcus aureus (S. aureus) isolates. Amikacin was the most susceptible antibiotic against all Gram-negative isolates. MDR Gram-negative bacteria accounted for 51.9% of wound infection isolates (95% CI: 45.95 to 58.33) while 6.3% (95% CI: 4.39 to 8.86) were XDR (nonsusceptibility to at least one agent in all but two or fewer antimicrobial categories). A high prevalence of bacterial isolates, with S. aureus as the predominant pathogen, showed high rates of multidrug resistance. This highlights the importance of monitoring antibiotic choices for prophylaxis and treatment in the study area. Full article

Fungal trunk disease (FTD) poses a significant threat to hazelnut (Corylus avellana L.) production worldwide. In Chile, the fungus Diplodia mutila, from the Botryosphaeriaceae family, has been frequently identified causing this disease in the Maule and Ñuble Regions. However, control measures for D. mutila remain limited. This research aimed to evaluate the effectiveness of chemical and biological fungicides against D. mutila under in vitro, controlled pot experiment, and field conditions. An in vitro screening of 30 fungicides was conducted. The effectiveness was assessed by measuring the length of vascular lesions in hazelnut branches inoculated with D. mutila mycelium disks under controlled and field conditions. Field trials were conducted in a hazelnut orchard in Ñiquén, Ñuble Region, Chile. The results showed that three biological and five chemical fungicides were selected in vitro with >31% inhibition after 14 days. In pot experiments, all fungicides reduced necrotic lesions on branches by 32% to 61%. In field experiments, the most effective systemic fungicides were fluopyram/tebuconazole, fluxapyroxad/pyraclostrobin, and tebuconazole, while the effectiveness of antagonists Pseudomonas protegens ChC7 and Bacillus subtilis QST713 varied with seasonal temperatures. Effective conventional and biological fungicides against D. mutila could be integrated into disease management programs to protect hazelnut wounds from infections. Full article

Finding safe and reliable alternatives to fungicides is currently one of the biggest challenges in agriculture. In this regard, this experiment investigated the effectiveness of different elicitors, botanical extracts and essential oils to control grey mold (Botrytis cinerea) and powdery mildew (Podosphaera aphanis) on strawberry plants. This trial was conducted in field conditions under a plastic tunnel with strawberry plants ‘Elsanta’. A first group of strawberry plants was treated before flowering with elicitors [acibenzolar-S-Methyl–(BTH), chitosan], botanical extracts (seaweed extract, alfalfa hydrolysate) and essential oils (thyme and juniper), and grey mold incidence on flowers was evaluated (Experiment 1). Furthermore, a second group of plants was treated before (Experiment 2) and after (Experiment 3) controlled inoculation with P. aphanis. The results indicated that the incidence of flower infected by B. cinerea was reduced by approximately 50% with thyme and juniper essential oils’ applications compared to the untreated control, with no significant difference observed compared to the commercial fungicide penconazole (positive control). As a consequence, the final yield of essential-oil-treated plants was +27% higher than that of non-treated plants. No significant differences emerged for other tested products against grey mold. However, gene expression analysis showed an up-regulation (>2 ÷ 5 folds as compared to control 4 days after application) of FaEDS1, FaLOX and PR gene expression (FaPR1, FaPR5, FaPR10) in leaves treated with BTH. The other natural substances tested also induced defense-related genes, albeit at a lower level than BTH. In Experiment 2, all treatments applied prior to inoculation significantly reduced the incidence and severity of powdery mildew as compared to control. At 28 days after inoculation, chitosan and thyme essential oil applications performed similarly to their positive controls (BTH and penconazole, respectively), showing a significant reduction in disease incidence (by −84 and −92%) as compared to control. Post-inoculum application of essential oils (Experiment 3) showed an efficacy similar to that of penconazole against powdery mildew. These results indicated that the tested substances could be used as alternatives to fungicides for the control of grey mold and powdery mildew in strawberry, therefore representing a valuable tool for the control of these fungal diseases under the framework of sustainable agriculture. Full article

(1) Background: Suitable harvest maturity stage selection and microbial inoculation during anaerobic fermentation are effective strategies for improving the quality of triticale (×Triticosecale) silage for ruminant nutrition. (2) Methods: In the present study, the fermentation characteristics, microbial communities, and their correlations were evaluated for triticale silages, as affected by Lactiplantibacillus plantarum (LP) inoculation at the heading, flowering, filling, milk-ripening, and wax-ripening stages. (3) Results: The results indicate that the filling and milk-ripening stages without LP inoculation resulted in lower pH and higher lactic acid than other harvest maturity stages (p < 0.05). Inoculating with LP decreased the pH at each harvest maturity stage, except for the filling stage, and increased the lactic acid concentration at the heading and filling stages (p < 0.05). The bacterial dynamics indicated that the abundances of Lactiplantebacilli and Monascus of the triticale silages without the LP inoculation were different between the harvest maturity stages (p < 0.05), and the abundance of Enterobacters was different between the harvest maturity stages in the triticale silage (p < 0.05). Remarkably, negative correlations were found between the Lactiplantebacillus, Monascus, and pH and positive correlations were found between the Lactiplantebacillus, Monascus, and lactic acid content (p < 0.05). (4) Conclusions: The filling and milk-ripening stages were the most suitable harvest maturity stages for the triticale silage. Inoculation with LP could enhance the fermentation quality, increase the abundances of beneficial microorganisms, and inhibit harmful microorganisms in triticale silage. Full article

The spectrum of enzymes required for complete lignocellulosic waste hydrolysis is too diverse to be secreted by a single organism. An alternative is to employ fungal co-cultures to obtain more diverse and complete enzymatic cocktails without the need to mix enzymes during downstream processing. This study evaluated the co-cultivation of Aspergillus brasiliensis and Trichoderma reesei RUT-C30 in different conditions using sugarcane bagasse as the carbon source. The resulting enzymatic cocktails were characterized according to the impact of strain inoculation time on enzymatic activities and proteome composition. Data revealed that the profile of each enzymatic extract was highly dependent on the order in which the participating fungi were inoculated. Some of the co-cultures exhibited higher enzyme activities compared to their respective monocultures for enzymes such as CMCase, pectinase, β-glucosidase, and β-xylosidase. Analysis of the T. reesei RUT-C30 and A. brasiliensis co-culture secretome resulted in the identification of 167 proteins, with 78 from T. reesei and 89 from A. brasiliensis. In agreement with the enzymatic results, proteome analysis also revealed that the timing of inoculation greatly influences the overall secretome, with a predominance of T. reesei RUT-C30 proteins when first inoculated or in simultaneous inoculation. Full article

Barley is the third most important cereal crop in terms of production in Canada, and Fusarium head blight (FHB) is one of the main fungal diseases of barley. FHB is caused by a species complex of Fusaria, of which Fusarium graminearum Schwabe is the main causal species of FHB epidemics in Canada. Field surveys show that two or more Fusarium species often co-exist within the same field or grain sample, and F. poae is reported as another important species in barley. This study aimed to determine the pathogenicity of F. graminearum, F. poae, and a co-inoculation of both species causing FHB in barley. Two susceptible barley cultivars were spray-inoculated at 10 to 14 days after heading. Phenotypic disease severity was rated on a scale of 0–9 at 4, 7, 14, 21, and 28 days after inoculation. There was a significant difference in FHB severity between F. graminearum and F. poae, where infection with F. graminearum produced more severe disease ratings. F. poae generated lower disease ratings and was not statistically different from the control. When heads were co-inoculated with both Fusarium species, the resulting FHB severity was unchanged relative to heads inoculated with F. graminearum only. The ratio of F. graminearum to F. poae genomic DNA was also no different than when heads were inoculated with F. graminearum alone, as quantified with ddPCR using markers specific to each species. The metabolomic analysis of sample extracts showed that F. graminearum-associated metabolites dominated the mycotoxin profile of co-inoculated samples, which corroborated our other findings where F. graminearum appeared to outcompete F. poae in barley. No significant effect on visual FHB disease ratings or fungal DNA detection was observed between the cultivars tested. However, there were some metabolome differences between cultivars in response to the challenge by both F. graminearum and F. poae. Full article

The occurrence and spread of Verticillium dahliae (V. dahliae) in cotton depends on the combined effects of pathogens, host plants, and the environment, among which temperature is one of the most important environmental factors. Studying how temperature impacts the occurrence of V. dahliae in cotton and the mechanisms governing host defense responses is crucial for disease prevention and control. Understanding the dual effects of temperature on both pathogens and hosts can provide valuable insights for developing effective strategies to manage this destructive fungal infection in cotton. This study was based on the deciduous V. dahliae Vd-3. Through cultivation at different temperatures, Vd-3 formed the most microsclerotia and had the largest colony diameter at 25 °C. Endospore toxins were extracted, and 48 h was determined to be the best pathogenic time point for endotoxins to infect cotton leaves through a chlorophyll fluorescence imaging system and phenotypic evaluation. Transcriptome sequencing was performed on cotton leaves infected with Vd-3 endotoxins for 48 h at different culture temperatures. A total of 34,955 differentially expressed genes (DEGs) were identified between each temperature and CK (no pathogen inoculation), including 17,422 common DEGs. The results of the enrichment analysis revealed that all the DEGs were involved mainly in photosynthesis and sugar metabolism. Among the 34,955 DEGs, genes in the biosynthesis and signal transduction pathways of jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) were identified, and their expression patterns were determined. A total of 5652 unique DEGs were clustered into six clusters using the k-means clustering algorithm, and the functions and main transcription factors (TFs) of each cluster were subsequently annotated. In addition, we constructed a gene regulatory network via weighted correlation network analysis (WGCNA) and identified twelve key genes related to cotton defense against V. dahliae at different temperatures, including four genes encoding transcription factors. These findings provide a theoretical foundation for investigating temperature regulation in V. dahliae infecting cotton and introduce novel genetic resources for enhancing resistance to this disease in cotton plants. Full article

Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of silver–zeolite NPs (0%, 2%, 4%, 5%). Discs were contaminated with C. albicans and S. mutans. The antimicrobial effect was tested by inoculating contaminated discs on Tryptic soy agar (TSA), Sabouraud Dextrose Agar (SDA), Tryptic soy broth (TSB), and Sabouraud dextrose broth (SDB). Forty rectangular 65 × 10 × 2.5 mm acrylic resin specimens were also classified into four groups (n = 10) according to concentrations of silver–zeolite NPs. For the color change, L, a, and b values of rectangular specimens were examined with a spectrophotometer. A three-point bending test was also performed using a Devotrans device to determine the flexural bond strength of rectangular specimens. Scanning electron microscope analysis (SEM/EDX analysis) was also performed. Results: In this study, the antimicrobial effect increased with the concentration of silver–zeolite NPs added to acrylic resin discs. In our study, adding 2% silver–zeolite NPs was more effective against C. albicans. The antimicrobial effect against S. mutans increased with concentration of silver–zeolite NPs (<0.001). The colonization of C. albicans was significantly reduced by silver–zeolite NPs. A significant increase was observed in the color change as the nanoparticle percentage ratio increased (p < 0.001). The flexural strength values of the groups containing 2% and 4% nanoparticles were found to be clinically acceptable. Conclusions: The study showed that bacterial and fungal colonization is significantly reduced by adding silver–zeolite nanoparticles to acrylic resin discs. Based on its antimicrobial, physical, and mechanical properties, we recommend adding 2% silver–zeolite nanoparticles to the acrylic resin material for optimal results. Full article

Brown-rot fungi are large fungi that can decompose the cell walls of wood; they are notable for their secretion of diverse and complex enzymes that synergistically hydrolyze natural wood cellulose molecules. Fomitopsis pinicola (F. pinicola) is a brown-rot fungus of interest for its ability to break down the cellulose in wood efficiently. In this study, through a combination of rDNA-ITS analysis and morphological observation, the wood decay pathogen infecting Korean pine (Pinus koraiensis Siebold and Zucc.) was identified. Endoglucanase (CMCase) and β-glucosidase were quantified using the DNS (3,5-Dinitrosalicylic acid) method, and the cellulase activity was optimized using a single-factor method and orthogonal test. The results revealed that the wood-decaying fungus NE1 identified was Fomitopsis pinicola with the ITS accession number OQ880566.1. The highest cellulase activity of the strain reached 116.94 U/mL under the condition of an initial pH of 6.0, lactose 15 g·L⁻¹, KH₂PO₄ 0.5 g·L⁻¹, NH₄NO₃ 15 g·L⁻¹, MgSO₄ 0.5 g·L⁻¹, VB₁ 0.4 g·L⁻¹, inoculated two 5 mm fungal cakes in 80 mL medium volume cultured 28 °C for 5 days. This laid a foundation for improving the degradation rate of cellulose and biotransformation research, as well as exploring the degradation of cellulose by brown rot fungi. Full article

Several studies have been devoted to seeking some beneficial plant-related microorganisms for a long time, and on this basis, it has been found that arbuscular mycorrhizal fungi (AMF) have a considerable positive impact on plant health as a biological fungal agent. In this study, we focused on the effects of different AMF on the growth dynamics and root configuration of licorice under saline and alkali conditions. The metabolites of licorice under different AMF were assessed using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Funneliformis mosseae (Fm) and Rhizophagus intraradices (Ri) were added as different AMF treatments, while the sterilized saline–alkali soil was treated as a control. Samples were taken in the R1 period (15 d after AMF treatment) and the R2 period (45 d after AMF treatment). The results showed that the application of AMF significantly increased the root growth of licorice and significantly increased the biomass of both shoot and root. A total of 978 metabolites were detected and divided into 12 groups including lipids, which accounted for 15.44%; organic acids and their derivatives, at 5.83%; benzene compounds and organic heterocyclic compounds, at 5.42%; organic oxides, at 3.78%; and ketones, accounting for 3.17%. Compared with the control, there were significant changes in the differential metabolites with treatment inoculated with AMF; the metabolic pathways and biosynthesis of secondary metabolites were the main differential metabolite enrichment pathways in the R1 period, and those in the R2 period were microbial metabolism in diverse environments and the degradation of aromatic compounds. In conclusion, the use of AMF as biofertilizer can effectively improve the growth of licorice, especially in terms of the root development and metabolites, in saline–alkali soil conditions. Full article