Effects of wheat intercropping on growth and occurrence of Fusarium wilt in watermelon.

Watermelon is commonly affected by Fusarium wilt in a monoculture cropping system. Wheat intercropping alleviates the affection of Fusarium wilt of watermelon. The objective of this study was to determine the effects of wheat and watermelon intercropping on watermelon growth and Fusarium wilt. Our results showed that wheat and watermelon intercropping promoted growth, increased chlorophyll content, and photosynthesis of watermelon. Meanwhile, wheat and watermelon intercropping inhibited watermelon Fusarium wilt occurrence, decreased spore numbers, increased root vigor, increased antioxidant enzyme activities, and decreased malondialdehyde (MDA) content in watermelon roots. Additionally, wheat and watermelon intercropping enhanced the bacterial colonies and total microbes growth in soil, decreased fungi and Fusarium oxysporum f. sp. niveum (FON) colonies, and increased soil enzyme activities in watermelon rhizosphere soil. Our results indicated that wheat and watermelon intercropping enhanced watermelon growth and decreased the incidence of Fusarium wilt in watermelon. These effects could be due to intercropping inducing physiological changes, regulating soil enzyme activities, and/or modulating soil microbial communities.

Natural dyes developed by microbial-nanosilver to produce antimicrobial and anticancer textiles.

Developing special textiles (for patients in hospitals for example) properties, special antimicrobial and anticancer, was the main objective of the current work. The developed textiles were produced after dyeing by the novel formula of natural (non-environmental toxic) pigments (melanin amended by microbial-AgNPs). Streptomyces torulosus isolate OSh10 with accession number KX753680.1 was selected as a superior producer for brown natural pigment. By optimization processes, some different pigment colors were observed after growing the tested strain on the 3 media. Dextrose and malt extract enhanced the bacteria to produce a reddish-black color. However, glycerol as the main carbon source and NaNO3 and asparagine as a nitrogen source were noted as the best for the production of brown pigment. In another case, starch as a polysaccharide was the best carbon for the production of deep green pigment. Peptone and NaNO3 are the best nitrogen sources for the production of deep green pigment. Microbial-AgNPs were produced by Fusarium oxysporum with a size of 7-21 nm, and the shape was spherical. These nanoparticles were used to produce pigments-nanocomposite to improve their promising properties. The antimicrobial of nanoparticles and textiles dyeing by nanocomposites was recorded against multidrug-resistant pathogens. The new nanocomposite improved pigments' dyeing action and textile properties. The produced textiles had anticancer activity against skin cancer cells with non-cytotoxicity detectable action against normal skin cells. The obtained results indicate to application of these textiles in hospital patients' clothes.

Biostimulant and antagonistic potential of endophytic fungi against fusarium wilt pathogen of tomato Fusarium oxysporum f. sp. lycopersici.

Endophytic fungal-based biopesticides are sustainable and ecologically-friendly biocontrol agents of several pests and diseases. However, their potential in managing tomato fusarium wilt disease (FWD) remains unexploited. This study therefore evaluated effectiveness of nine fungal isolates against tomato fusarium wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL) in vitro using dual culture and co-culture assays. The efficacy of three potent endophytes that inhibited the pathogen in vitro was assessed against FWD incidence, severity, and ability to enhance growth and yield of tomatoes in planta. The ability of endophytically-colonized tomato (Solanum lycopersicum L.) plants to systemically defend themselves upon exposure to FOL were also assessed through defence genes expression using qPCR. In vitro assays showed that endophytes inhibited and suppressed FOL mycelial growth better than entomopathogenic fungi (EPF). Endophytes Trichoderma asperellum M2RT4, Hypocrea lixii F3ST1, Trichoderma harzianum KF2R41, and Trichoderma atroviride ICIPE 710 had the highest (68.84-99.61%) suppression and FOL radial growth inhibition rates compared to EPF which exhibited lowest (27.05-40.63%) inhibition rates. Endophytes T. asperellum M2RT4, H. lixii F3ST1 and T. harzianum KF2R41 colonized all tomato plant parts. During the in planta experiment, endophytically-colonized and FOL-infected tomato plants showed significant reduction of FWD incidence and severity compared to non-inoculated plants. In addition, these endophytes contributed to improved growth promotion parameters and yield. Moreover, there was significantly higher expression of tomato defence genes in T. asperellum M2RT4 colonized than in un-inoculated tomato plants. These findings demonstrated that H. lixii F3ST1 and T. asperellum M2RT4 are effective biocontrol agents against FWD and could sustainably mitigate tomato yield losses associated with fusarium wilt.

Study on the inhibitory activity and mechanism of Mentha haplocalyx essential oil nanoemulsion against Fusarium oxysporum growth.

Mentha haplocalyx essential oil (MEO) has demonstrated inhibitory effects on Fusarium oxysporum. Despite its environmentally friendly properties as a natural product, the limited water solubility of MEO restricts its practical application in the field. The use of nanoemulsion can improve bioavailability and provide an eco-friendly approach to prevent and control Panax notoginseng root rot. In this study, Tween 80 and anhydrous ethanol (at a mass ratio of 3) were selected as carriers, and the ultrasonic method was utilized to produce a nanoemulsion of MEO (MNEO) with an average particle size of 26.07 nm. Compared to MTEO (MEO dissolved in an aqueous solution of 2% DMSO and 0.1% Tween 80), MNEO exhibited superior inhibition against F. oxysporum in terms of spore germination and hyphal growth. Transcriptomics and metabolomics results revealed that after MNEO treatment, the expression levels of certain genes related to glycolysis/gluconeogenesis, starch and sucrose metabolism were significantly suppressed along with the accumulation of metabolites, leading to energy metabolism disorder and growth stagnation in F. oxysporum. In contrast, the inhibitory effect from MTEO treatment was less pronounced. Furthermore, MNEO also demonstrated inhibition on meiosis, ribosome function, and ribosome biogenesis in F. oxysporum growth process. These findings suggest that MNEO possesses enhanced stability and antifungal activity, which effectively hinders F. oxysporum through inducing energy metabolism disorder, meiotic stagnation, as well as ribosome dysfunction, thus indicating its potential for development as a green pesticide for prevention and control P. notoginseng root rot caused by F.oxyosporum.

Zinc finger transcription factor ZFP1 is associated with growth, conidiation, osmoregulation, and virulence in the Polygonatum kingianum pathogen Fusarium oxysporum.

Rhizome rot is a destructive soil-borne disease of Polygonatum kingianum and adversely affects the yield and sustenance of the plant. Understanding how the causal fungus Fusarium oxysporum infects P. kingianum may suggest effective control measures against rhizome rot. In germinating conidia of infectious F. oxysporum, expression of the zinc finger transcription factor gene Zfp1, consisting of two C2H2 motifs, was up-regulated. To characterize the critical role of ZFP1, we generated independent deletion mutants (zfp1) and complemented one mutant with a transgenic copy of ZFP1 (zfp1 tZFP1). Mycelial growth and conidial production of zfp1 were slower than those of wild type (ZFP1) and zfp1 tZFP1. Additionally, a reduced inhibition of growth suggested zfp1 was less sensitive to conditions promoting cell wall and osmotic stresses than ZFP1 and zfp1 tZFP1. Furthermore pathogenicity tests suggested a critical role for growth of zfp1 in infected leaves and rhizomes of P. kingianum. Thus ZFP1 is important for mycelial growth, conidiation, osmoregulation, and pathogenicity in P. kingianum.

The antagonistic role of an E3 ligase pair in regulating plant NLR-mediated autoimmunity and fungal pathogen resistance.

Plant immune homeostasis is achieved through a balanced immune activation and suppression, enabling effective defense while averting autoimmunity. In Arabidopsis, disrupting a mitogen-activated protein (MAP) kinase cascade triggers nucleotide-binding leucine-rich-repeat (NLR) SUPPRESSOR OF mkk1/2 2 (SUMM2)-mediated autoimmunity. Through an RNAi screen, we identify PUB5, a putative plant U-box E3 ligase, as a critical regulator of SUMM2-mediated autoimmunity. In contrast to typical E3 ligases, PUB5 stabilizes CRCK3, a calmodulin-binding receptor-like cytoplasmic kinase involved in SUMM2 activation. A closely related E3 ligase, PUB44, functions oppositely with PUB5 to degrade CRCK3 through monoubiquitylation and internalization. Furthermore, CRCK3, highly expressed in roots and conserved across plant species, confers resistance to Fusarium oxysporum, a devastating soil-borne fungal pathogen, in both Arabidopsis and cotton. These findings demonstrate the antagonistic role of an E3 ligase pair in fine-tuning kinase proteostasis for the regulation of NLR-mediated autoimmunity and highlight the function of autoimmune activators in governing plant root immunity against fungal pathogens.

Agave Wilt Susceptibility by Reduction of Free Hexoses in Root Tissue of Agave tequilana Weber var. azul Commercial Plants in the Fructan Accumulation Process.

Agave tequilana stems store fructan polymers, the main carbon source for tequila production. This crop takes six or more years for industrial maturity. In conducive conditions, agave wilt disease increases the incidence of dead plants after the fourth year. Plant susceptibility induced for limited photosynthates for defense is recognized in many crops and is known as "sink-induced loss of resistance". To establish whether A. tequilana is more prone to agave wilt as it ages, because the reduction of water-soluble carbohydrates in roots, as a consequence of greater assembly of highly polymerized fructans, were quantified roots sucrose, fructose, and glucose, as well as fructans in stems of agave plants of different ages. The damage induced by inoculation with Fusarium solani or F. oxysporum in the roots or xylem bundles, respectively, was recorded. As the agave plant accumulated fructans in the stem as the main sink, the amount of these hexoses diminished in the roots of older plants, and root rot severity increased when plants were inoculated with F. solani, as evidence of more susceptibility. This knowledge could help to structure disease management that reduces the dispersion of agave wilt, dead plants, and economic losses at the end of agave's long crop cycle.

Distinguishing between Wheat Grains Infested by Four Fusarium Species by Measuring with a Low-Cost Electronic Nose.

An electronic device based on the detection of volatile substances was developed in response to the need to distinguish between fungal infestations in food and was applied to wheat grains. The most common pathogens belong to the fungi of the genus Fusarium: F. avenaceum, F. langsethiae, F. poae, and F. sporotrichioides. The electronic nose prototype is a low-cost device based on commercially available TGS series sensors from Figaro Corp. Two types of gas sensors that respond to the perturbation are used to collect signals useful for discriminating between the samples under study. First, an electronic nose detects the transient response of the sensors to a change in operating conditions from clean air to the presence of the gas being measured. A simple gas chamber was used to create a sudden change in gas composition near the sensors. An inexpensive pneumatic system consisting of a pump and a carbon filter was used to supply the system with clean air. It was also used to clean the sensors between measurement cycles. The second function of the electronic nose is to detect the response of the sensor to temperature disturbances of the sensor heater in the presence of the gas to be measured. It has been shown that features extracted from the transient response of the sensor to perturbations by modulating the temperature of the sensor heater resulted in better classification performance than when the machine learning model was built from features extracted from the response of the sensor in the gas adsorption phase. By combining features from both phases of the sensor response, a further improvement in classification performance was achieved. The E-nose enabled the differentiation of F. poae from the other fungal species tested with excellent performance. The overall classification rate using the Support Vector Machine model reached 70 per cent between the four fungal categories tested.

Development of a marker recyclable CRISPR/Cas9 system for scarless and multigene editing in Fusarium fujikuroi.

Iterative metabolic engineering of Fusarium fujikuroi has traditionally been hampered by its low homologous recombination efficiency and scarcity of genetic markers. Thus, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas9) system has emerged as a promising tool for precise genome editing in this organism. Some integrated CRISPR/Cas9 strategies have been used to engineer F. fujikuroi to improve GA3 production capabilities, but low editing efficiency and possible genomic instability became the major obstacle. Herein, we developed a marker recyclable CRISPR/Cas9 system for scarless and multigene editing in F. fujikuroi. This system, based on an autonomously replicating sequence, demonstrated the capability of a single plasmid harboring all editing components to achieve 100%, 75%, and 37.5% editing efficiency for single, double, and triple gene targets, respectively. Remarkably, even with a reduction in homologous arms to 50 bp, we achieved a 12.5% gene editing efficiency. By employing this system, we successfully achieved multicopy integration of the truncated 3-hydroxy-3-methyl glutaryl coenzyme A reductase gene (tHMGR), leading to enhanced GA3 production. A key advantage of our plasmid-based gene editing approach was the ability to recycle selective markers through a simplified protoplast preparation and recovery process, which eliminated the need for additional genetic markers. These findings demonstrated that the single-plasmid CRISPR/Cas9 system enables rapid and precise multiple gene deletions/integrations, laying a solid foundation for future metabolic engineering efforts aimed at industrial GA3 production.

Cytogenetic identification and molecular mapping for the wheat-Thinopyrum ponticum introgression line with resistance to Fusarium head blight.

KEY MESSAGE: Xinong 511, a new wheat-Thinopyrum ponticum variety with excellent fusarium head blight resistance, the QTLs were mapped to the wheat chromosomes 5B and 7A with named QFhb.nwafu-5B and QFhb.nwafu-7A, respectively. Novel Fusarium head blight (FHB) resistance germplasms and genes are valuable for wheat improvement and breeding efforts. Thinopyrum ponticum, a wild relative of common wheat, is a valuable germplasm of disease resistance for wheat improvement and breeding. Xinong 511 (XN511) is a high-quality wheat variety widely cultivated in the Yellow and Huai Rivers Valley of China with stable FHB-resistance. Through analysis of pedigree materials of the wheat cultivar XN511, we found that the genetic material and FHB resistance from Th. ponticum were transmitted to the introgression line, indicating that the FHB resistance in XN511 likely originates from Th. ponticum. To further explore the genetic basis of FHB resistance in XN511, QTL mapping was conducted using the RILs population of XN511 and the susceptible line Aikang 58 (AK58). Survey with makers closely-linked to Fhb1, Fhb2, Fhb4, Fhb5, and Fhb7, indicated that both XN511 and the susceptible lines do not contain these QTL. Using bulked segregant analysis RNA-seq (BSR-Seq) and newly developed allele-specific PCR (AS-PCR) markers, QTLs in XN511 were successfully located on wheat chromosomes 5B and 7A. These findings are significant for further understanding and utilizing FHB resistance genes in wheat improvement.

Linking landscape habitats with prevalence of fusarium wilt disease of cashew crop in Tanzania.

Epidemic of Cashew Fusarium wilt disease (CFWD) has been a continuous focal challenge in the cashew farming, in Tanzania. Limited to edaphic conditions as a major factor in its epidemic, the current study aimed to assess the habitat-disease relationship. Purposive surveys involving assessment of disease prevalence and habitat compositions were conducted across four landscapes of southeastern zone from 2019 to 2023. Findings revealed a widespread of CFWD across diversified landscapes possessing varying habitat characteristics, mainly cultivated land with mature cashew, brownish sand loamy soils, grassland or shrub vegetation, seasonal river streamlines and natural water wells. The highest disease incidence and severity were noted at Nachingwea/Masasi plain (99.28:88.34%) followed by Liwale inland plain (98.64:89.3%), Coastal zone (72.72:59.83%) and Tunduru dissected plain (62.13:54.54%). The habitat characteristics were strongly similar within the landscape (0.86-Jaccard index) except between villages of the coastal zone (0.71-Jaccard index). Across landscapes, Nachingwea/Masasi plains and the Coastal zone were strongly similar to Tunduru dissected plain (0.63-1.0-Jaccard index), but strongly dissimilar with the Liwale inland plain (0.67-0.70- Jaccard distance). Furthermore, the presence of greater than 0.5 suitability indices across landscapes were revealed, with Liwale inland plain having strongest suitability index of 0.743 followed by Coastal zone (0.681), Tunduru dissected plain (0.617) and Nachingwea/Masasi plain. Significantly, the habitats had an increase of 0.1 suitability index, and positively correlated with disease prevalence by triggering disease incidence of 13.9% and severity of 31.4%. The study for the first time revealed the presence of an association between disease prevalence and landscape habitat characteristics of southeastern, Tanzania; paving the way to inclusive thinking of habitat as one of the drivers in the prevalence of fusarium wilt disease of cashews. Further research on the genetic coevolution of Fusarium oxysporum across landscapes to strengthen disease risk management in the cashew industry is recommended.

Pseudonectria keratitis-emerging pathogenic fungi in the eye.

BACKGROUND: Infectious keratitis, a significant contributor to blindness, with fungal keratitis accounting for nearly half of cases, poses a formidable diagnostic and therapeutic challenge due to its delayed clinical presentation, prolonged culture times, and the limited availability of effective antifungal medications. Furthermore, infections caused by rare fungal strains warrant equal attention in the management of this condition. CASE PRESENTATION: A case of fungal keratitis was presented, where corneal scraping material culture yielded pink colonies. Lactophenol cotton blue staining revealed distinctive spore formation consistent with the Fusarium species. Further analysis using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) identified the causative agent as Fusarium proliferatum. However, definitive diagnosis of Pseudonectria foliicola infection was confirmed through ITS sequencing. The patient's recovery was achieved with a combination therapy of voriconazole eye drops and itraconazole systemic treatment. CONCLUSION: Pseudonectria foliicola is a plant pathogenic bacterium that has never been reported in human infections before. Therefore, ophthalmologists should consider Pseudonectria foliicola as a possible cause of fungal keratitis, as early identification and timely treatment can help improve vision in most eyes.

[Construction of ATMT system of Fusarium oxysporum and evaluation of its promoting effect on Glycyrrhiza uralensis].

This study aims to evaluate the in vivo function of Fusarium oxysporum in Glycyrrhiza uralensis by salt tolerance,indoleacetic acid(IAA) production capacity, phosphate-dissolving capacity, and iron carrier production capacity. The stable genetic transformation system of the F. oxysporum was established by Agrobacterium tumefaciens-mediated genetic transformation( ATMT)technology, and the stability and staining efficiency of transformants were detected by the cloning of the marker gene green fluorescent protein(GFP) and the efficiency of ß-glucuronidase staining(GUS). Efficient and stable transformants were selected for restaining G. uralensis and evaluating its influence on the growth of the G. uralensis seedlings. The results show that F. oxysporum has good salt tolerance and could still grow on potato glucose agar(PDA) medium containing 7% sodium chloride, but the growth rate slows down with the increase in sodium chloride content in PDA medium. F. oxysporum has the function of producing indoleacetic acid, and the concentration of IAA in its fermentation broth is about 3. 32 mg · m L~(-1). In this study, the genetic transformation system of F. oxysporum is successfully constructed, and the ATMT system is efficient and stable. One transformant with both high staining efficiency and genetic stability is selected, and the restaining rate of the transformant in G. uralensis is 76. 92%, which could significantly improve the main root length of one-month-old G. uralensis seedlings and promote the growth and development of G. uralensis seedlings. The results of this study can lay the foundation for the development of biological bacterial fertilizer and the growth regulation of high-quality G. uralensis.

Intercropping improves faba bean photosynthesis and reduces disease caused by Fusarium commune and cinnamic acid-induced stress.

Modern intensive cropping systems often contribute to the accumulation of phenolic acids in the soil, which promotes the development of soilborne diseases. This can be suppressed by intercropping. This study analyzed the effects of intercropping on Fusarium wilt based on its effect on photosynthesis under stress by the combination of Fusarium commune and cinnamic acid. The control was not inoculated with F. commune, while the faba bean plants (Vicia faba L.) were inoculated with this pathogen in the other treatments. The infected plants were also treated with cinnamic acid. This study examined the development of Fusarium wilt together with its effects on the leaves, absorption of nutrients, chlorophyll fluorescence parameters, contents of photosynthetic pigments, activities of photosynthetic enzymes, gas exchange parameters, and the photosynthetic assimilates of faba bean from monocropping and intercropping systems. Under monocropping conditions, the leaves of the plants inoculated with F. commune grew significantly less, and there was enhanced occurrence of the Fusarium wilt compared with the control. Compared with the plants solely inoculated with F. commune, the exogenous addition of cinnamic acid to the infected plants significantly further reduced the growth of faba bean leaves and increased the occurrence of Fusarium wilt. A comparison of the combination of F. commune and cinnamic acid in intercropped wheat and faba bean compared with monocropping showed that intercropping improved the absorption of nutrients, increased photosynthetic pigments and its contents, electron transport, photosynthetic enzymes, and photosynthetic assimilates. The combination of these factors reduced the occurrence of Fusarium wilt in faba bean and increased the growth of its leaves. These results showed that intercropping improved the photosynthesis, which promoted the growth of faba bean, thus, reducing the development of Fusarium wilt following the stress of infection by F. commune and cinnamic acid. This research should provide more information to enhance sustainable agriculture.

Enhanced anticancer activity of silver doped zinc oxide magnetic nanocarrier loaded with sorafenib for hepatocellular carcinoma treatment.

Drug delivery is the process or method of delivering a pharmacological product to have therapeutic effects on humans or animals. The use of nanoparticles to deliver medications to cells is driving the present surge in interest in improving human health. Green nanodrug delivery methods are based on chemical processes that are acceptable for the environment or that use natural biomaterials such as plant extracts and microorganisms. In this study, zinc oxide-superparamagnetic iron oxide-silver nanocomposite was synthesized via green synthesis method using Fusarium oxysporum fungi mycelia then loaded with sorafenib drug. The synthesized nanocomposites were characterized by UV-visibile spectroscopy, FTIR, TEM and SEM techniques. Sorafenib is a cancer treatment and is also known by its brand name, Nexavar. Sorafenib is the only systemic medication available in the world to treat hepatocellular carcinoma. Sorafenib, like many other chemotherapeutics, has side effects that restrict its effectiveness, including toxicity, nausea, mucositis, hypertension, alopecia, and hand-foot skin reaction. In our study, 40 male albino rats were given a single dose of diethyl nitrosamine (DEN) 60 mg/kg b.wt., followed by carbon tetrachloride 2 ml/kg b.wt. twice a week for one month. The aim of our study is using the zinc oxide-superparamagnetic iron oxide-silver nanocomposite that was synthesized by Fusarium oxysporum fungi mycelia as nanocarrier for enhancement the sorafenib anticancer effect.

Physiological and genomic insights into a psychrotrophic drought-tolerant bacterial consortium for crop improvement in cold, semiarid regions.

The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions.

Field isolates of Beauveria bassiana exhibit biological heterogeneity in multitrophic interactions of agricultural importance.

Beauveria bassiana (Bb) is a widespread entomopathogenic fungus widely used in agriculture for crop protection. Other than pest control, fungi belonging to the B. bassiana complex represent an important microbial resource in agroecosystems, considering their multiple interactions with other microorganisms as antagonists of phytopathogens, or with plants as endophytic colonizers and growth promoters. Here, we characterised field collected or commercial isolates of B. bassiana relative to the environmental factors that affect their growth. We further compared the metabolome, the entomopathogenic potential and biocontrol activity of the tested isolates respectively on the insect pest Spodoptera littoralis or against the fungal plant pathogen Fusarium oxysporum. Our analysis revealed that the B. bassiana complex is characterised by a high level of inter-isolate heterogeneity in terms of nutritional requirements, establishment of intra- or inter-kingdom interactions, and the nature of metabolites produced. Interestingly, certain B. bassiana isolates demonstrated a preference for low nutrient plant-derived media, which hints at their adaptation towards an endophytic lifestyle over a saprophytic one. In addition, there was a noticeable variation among different B. bassiana isolates in their capacity to kill S. littoralis larvae in a contact infection test, but not in an intrahaemocoelic injection experiment, suggesting a unique level of adaptability specific to the host. On the other hand, most B. bassiana isolates exhibited similar biocontrol efficacy against the soil-dwelling ascomycete F. oxysporum f. sp. lycopersici, a pathogen responsible for vascular wilt disease in tomato plants, effectively averting wilting. Overall, we show that the effectiveness of B. bassiana isolates can greatly vary, emphasising the importance of isolate selection and nutritional adaptability consideration for their use in sustainable agriculture.

Unveiling the Mechanism of Phenamacril Resistance in F. graminearum: Computational and Experimental Insights into the C423A Mutation in FgMyoI.

Phenamacril (PHA) is a highly selective fungicide for controlling fusarium head blight (FHB) mainly caused by F. graminearum and F. asiaticum. However, the C423A mutation in myosin I of F. graminearum (FgMyoI) leads to natural resistance to PHA. Here, based on the computational approaches and biochemical validation, we elucidate the atomic-level mechanism behind the natural resistance of F. graminearum to the fungicide PHA due to the C423A mutation in FgMyoI. The mutation leads to a rearrangement of pocket residues, resulting in increased size and flexibility of the binding pocket, which impairs the stable binding of PHA. MST experiments confirm that the mutant protein FgMyoIC423A exhibits significantly reduced affinity for PHA compared to wild-type FgMyoI and the nonresistant C423K mutant. This decreased binding affinity likely underlies the development of PHA resistance in F. graminearum. Conversely, the nonresistant C423K mutant retains sensitivity to PHA due to the introduction of a strong hydrogen bond donor, which facilitates stable binding of PHA in the pocket. These findings shed light on the molecular basis of PHA resistance and provide new directions for the creation of new myosin inhibitors.

Structural and Functional Characterization of New Lipid Transfer Proteins with Chitin-Binding Properties: Insights from Protein Structure Prediction, Molecular Docking, and Antifungal Activity.

Faced with the emergence of multiresistant microorganisms that affect human health, microbial agents have become a serious global threat, affecting human health and plant crops. Antimicrobial peptides have attracted significant attention in research for the development of new microbial control agents. This work's goal was the structural characterization and analysis of antifungal activity of chitin-binding peptides from Capsicum baccatum and Capsicum frutescens seeds on the growth of Candida and Fusarium species. Proteins were initially submitted to extraction in phosphate buffer pH 5.4 and subjected to chitin column chromatography. Posteriorly, two fractions were obtained for each species, Cb-F1 and Cf-F1 and Cb-F2 and Cf-F2, respectively. The Cb-F1 (C. baccatum) and Cf-F1 (C. frutescens) fractions did not bind to the chitin column. The electrophoresis results obtained after chromatography showed two major protein bands between 3.4 and 14.2 kDa for Cb-F2. For Cf-F2, three major bands were identified between 6.5 and 14.2 kDa. One band from each species was subjected to mass spectrometry, and both bands showed similarity to nonspecific lipid transfer protein. Candida albicans and Candida tropicalis had their growth inhibited by Cb-F2. Cf-F2 inhibited the development of C. albicans but did not inhibit the growth of C. tropicalis. Both fractions were unable to inhibit the growth of Fusarium species. The toxicity of the fractions was tested in vivo on Galleria mellonella larvae, and both showed a low toxicity rate at high concentrations. As a result, the fractions have enormous promise for the creation of novel antifungal compounds.

Reference genes for RT-qPCR analysis in Musa acuminata genotypes contrasting in resistance to Fusarium oxysporum f. sp. cubense subtropical race 4.

Banana (Musa spp.) is the most widely consumed fruit globally. Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is a highly threatening disease to banana production. Resistance genes to Foc exist in wild Musa genotypes such as Musa acuminata subsp. burmannicoides var. Calcutta 4. Whilst real-time PCR (RT-qPCR) is appropriate for accurate analysis of gene expression in pathways involved in host defence responses, reference genes with stable expression under specific biotic stress conditions and host tissue types are necessary for normalization of sample variation. In this context, the stability in potential host reference genes ACT1, APT, EF1α, GAPDH, αTUB, RAN, UBIQ1, UBIQ2, ßTUB1, ßTUB3, L2 and ACTA1 was evaluated in total RNA samples from root tissues in Calcutta 4 (resistant) and Musa sp. cultivar Prata-anã (susceptible) extracted during interaction with Foc subtropical race 4 (STR4). Expression stability was calculated using the algorithms geNorm, NormFinder and BestKeeper. ßTUB3 and L2 were identified as the most stable in Calcutta 4, with ACTA1 and GAPDH the most stable in Prata-anã. These reference genes for analysis of gene expression modulation in the Musa-Foc STR4 pathosystem are fundamental for advancing understanding of host defence responses to this important pathogen.