A pilot study of the in vitro efficacy of different concentrations of Duddingtonia flagrans for the control of gastrointestinal nematodes of sheep.

Duddingtonia flagrans is a nematode trapping fungus used for the control of gastrointestinal nematodes in livestock. The quantity of chlamydospores of D. flagrans required for the reduction of third-stage larvae (L3) of sheep gastrointestinal nematodes (GIN) is largely unknown, and a matter of discussion. The aim of this experiment was to determine in vitro the nematophagous activity of four different concentrations of D. flagrans (1000, 3000, 6250, or 11000 chlamydospores/ml) in the presence of varying numbers of GIN third-stage larvae (L3) (500, 1000, 1500). Additionally, the study sought to evaluate the efficacy of this fungus on Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis and Chabertia ovina. The results showed that as fungal concentrations increased, so did the larval reduction of third-stage infective larvae in each test. L3s number was not a determining factor in the efficacy against GIN. The comparison between various concentrations of chlamydospores revealed significant differences, particularly between 1000 and 11000 chlamydospores (P≤0.05). Regarding the larval reduction of the GIN species considered, D. flagrans demonstrated the same effectiveness across all species tested. The results of the current study confirm the efficacy and underscore the importance of D. flagrans as an alternative for controlling of GIN.

Genetic diversity and population structure of Botryosphaeria dothidea and Neofusicoccum parvum on English walnut (Juglans regia L.) in France.

Botryosphaeriaceae species are the major causal agents of walnut dieback worldwide, along with Diaporthe species. Botryosphaeria dothidea and Neofusicoccum parvum are the only two Botryosphaeriaceae species associated with this recently emergent disease in France, and little is known about their diversity, structure, origin and dispersion in French walnut orchards. A total of 381 isolates of both species were genetically typed using a sequence-based microsatellite genotyping (SSR-seq) method. This analysis revealed a low genetic diversity and a high clonality of these populations, in agreement with their clonal mode of reproduction. The genetic similarity among populations, regardless of the tissue type and the presence of symptoms, supports the hypothesis that these pathogens can move between fruits and twigs and display latent pathogen lifestyles. Contrasting genetic patterns between N. parvum populations from Californian and Spanish walnut orchards and the French ones suggested no conclusive evidence for pathogen transmission from infected materials. The high genetic similarity with French vineyards populations suggested instead putative transmission between these hosts, which was also observed with B. dothidea populations. Overall, this study provides critical insight into the epidemiology of two important pathogens involved in the emerging dieback of French walnut orchards, including their distribution, potential to mate, putative origin and disease pathways.

In vitro antiplasmodial and anticancer analyses of endophytic fungal extracts isolated from selected Nigerian medicinal plants.

Ethnomedicinal plants are thought to have better prospects of harboring endophytes that produce natural products with pharmacological activities. This study aimed to investigate the antiplasmodial and anticancer properties of secondary metabolites of endophytic fungi from three medicinal plants. The endophytic fungi included Lasiodiplodia theobromae isolated from Cola acuminata, Curvularia lunata Bv4 isolated from Bambusa vulgaris, and Curvularia lunata Eg7 isolated from Elaeis guineensis. The identification of the fungi was based on the internal transcribed spacer (ITS-rDNA) sequence. The fungi were subjected to solid-state fermentation and the secondary metabolites were extracted with ethyl acetate. In vitro antiplasmodial screening of extracts was performed using the SYBR green I-based fluorescence assay on the chloroquine-resistant Plasmodium falciparum strain DD2. The cytotoxicity of the extracts on human red blood cells and Jurkat (leukemia) cells was assessed using the tetrazolium-based colorimetric MTT assay. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the constituents of the fungal extracts. The extract of L. theobromae showed the best antiplasmodial activity against chloroquine-resistant P. falciparum (IC50 = 5.4 µg/mL) and was not harmful to erythrocytes (CC50 > 100 µg/mL). All three fungal extracts showed a weak cytotoxic effect against Jukart cell lines (CC50 > 100 µg/mL). GC-MS analysis of the three endophytic fungal extracts revealed the presence of forty major bioactive compounds, including: oxalic acid, isobutyl nonyl ester, 2,4-di-tert-butylphenol, and hexadecanoic acid, among others. The endophytic fungi from the medicinal plants in this study were promising sources of bioactive compounds that could be further evaluated as novel drugs for the treatment of malaria caused by P. falciparum-resistant strains.

Pyrolysed maize feedstock utilization in combination with Trichoderma viride against Macrophomina phaseolina.

Maize cultivation is under the growing threat of charcoal rot (Macrophomina phaseolina). Chemical control of diseases imparts serious health hazards to humans and the ecosystem. Biochar as an alternative disease management approach has been under consideration of the researchers for some time now. The biochar utilized in this study was derived from maize stalks and cobs. Crystallographic structure, inorganic minerals content and size of maize biochar were analyzed by powder X-ray diffractometer, while scanning electron microscopy revealed rough, irregular, tubular structure of the biochar surface. EDX spectra revealed that the maize biochar composition was dominated by 'C' followed by 'O'. The current study was designed to determine the synergistic effect of maize biochar (MB), and biocontrol agent (BCA) Trichoderma viride as soil amendments on the suppression of M. phaseolina. In vitro bioassays were conducted to check the efficiency of antagonistic effect of Trichoderma spp., in combination with maize biochar. On the basis of maximum mycelial growth inhibition T. viride was selected for a glasshouse experiment. Maize plants were grown in pots containing a mixture of soil with MB at application at the rate of 3 and 6% (v/v) separately, associated with or without T. viride. Treatments amended with 3% MB inoculated with M. phaseolina significantly reduced the percentage disease severity index by 40%. While in the presence of T. viride, 3% MB showed maximum disease suppression and a minimum percentage severity index i.e. 60 and 20%, respectively. Highest nitrogen contents were 18.4 g kg-1 observed in treatment 6% MB, while highest phosphorus and potassium contents were 3.11 and 15.2 g kg-1, respectively in the treatment with 3% MB. Conclusively, the effect of variable concentrations of maize biochar and T. viride as soil amendment was evident on the development of charcoal rot, growth and physiology of maize plants. According to the available literature, our report is the first on the implementation of biochar in synergism with T. viride to suppress the charcoal rot in maize.

N6-methyladenosine RNA methyltransferase CpMTA1 mediates CpAphA mRNA stability through a YTHDF1-dependent m6A modification in the chestnut blight fungus.

In eukaryotic cells, N6-methyladenosine (m6A) is the most prevalent RNA epigenetic modification that plays crucial roles in multiple biological processes. Nevertheless, the functions and regulatory mechanisms of m6A in phytopathogenic fungi are poorly understood. Here, we showed that CpMTA1, an m6A methyltransferase in Cryphonectria parasitica, plays a crucial role in fungal phenotypic traits, virulence, and stress tolerance. Furthermore, the acid phosphatase gene CpAphA was implicated to be a target of CpMTA1 by integrated analysis of m6A-seq and RNA-seq, as in vivo RIP assay data confirmed that CpMTA1 directly interacts with CpAphA mRNA. Deletion of CpMTA1 drastically lowered the m6A level of CpAphA and reduced its mRNA expression. Moreover, we found that an m6A reader protein CpYTHDF1 recognizes CpAphA mRNA and increases its stability. Typically, the levels of CpAphA mRNA and protein exhibited a positive correlation with CpMTA1 and CpYTHDF1. Importantly, site-specific mutagenesis demonstrated that the m6A sites, A1306 and A1341, of CpAphA mRNA are important for fungal phenotypic traits and virulence in C. parasitica. Together, our findings demonstrate the essential role of the m6A methyltransferase CpMTA1 in C. parasitica, thereby advancing our understanding of fungal gene regulation through m6A modification.

Characteristics of Corynespora cassiicola, the causal agent of tobacco Corynespora leaf spot, revealed by genomic and metabolic phenomic analysis.

Corynespora cassiicola is a highly diverse fungal pathogen that commonly occurs in tropical, subtropical, and greenhouse environments worldwide. In this study, the isolates were identified as C. cassiicola, and the optimum growth and sporulation were studied. The phenotypic characteristics of C. cassiicola, concerning 950 different growth conditions, were tested using Biolog PM plates 1-10. In addition, the strain of C. cassiicola DWZ from tobacco hosts was sequenced for the using Illumina PE150 and Pacbio technologies. The host resistance of tobacco Yunyan 87 with different maturity levels was investigated. In addition, the resistance evaluation of 10 common tobacco varieties was investigated. The results showed that C. cassiicola metabolized 89.47% of the tested carbon source, 100% of the nitrogen source, 100% of the phosphorus source, and 97.14% of the sulfur source. It can adapt to a variety of different osmotic pressure and pH environments, and has good decarboxylase and deaminase activities. The optimum conditions for pathogen growth and sporulation were 25-30 °C, and the growth was better on AEA and OA medium. The total length of the genome was 45.9 Mbp, the GC content was 51.23%, and a total of 13,061 protein-coding genes, 202 non-coding RNAs and 2801 and repeat sequences were predicted. Mature leaves were more susceptible than proper mature and immature leaves, and the average diameter of diseased spots reached 17.74 mm at 12 days. None of the tested ten cultivars exhibited obvious resistance to Corynespora leaf spot of tobacco, whereby all disease spot diameters reached > 10 mm and > 30 mm when at 5 and 10 days after inoculation, respectively. The phenotypic characteristics, genomic analysis of C. cassiicola and the cultivar resistance assessment of this pathogen have increased our understanding of Corynespora leaf spot of tobacco.

Phenotypic diversity in qualitative and quantitative traits for selection of high yield potential field pea genotypes.

Field pea (Pisum sativum L.) needs improvement to increase productivity due to its high price and demand. However, the incidence of powdery mildew (PM) disease limits its production. This study aimed to analyze the diversity of qualitative and quantitative traits against powdery mildew resistance by utilizing cluster and principal component analysis to explore PM resistance high-yield potential field peas. Shannon-Weaver's diversity index (H') displayed high intra-genotype diversity for quantitative and qualitative aspects. Heterogeneity was identified for resistance against powdery mildew infections. Eighty-five genotypes were divided into five groups using Mohalanobis generalized distance (D2) statistics. The highest inter-cluster D2 value was observed between clusters 2 and 3 (11.89) while the lowest value was found between clusters 3 and 4 (2.06). Most of the genotypes had noticeable differences, so these could be employed in a crossing scheme. Twelve genotypes were extremely resistant, 29 genotypes were resistant, 25 genotypes were moderately resistant, 18 genotypes were fairly susceptible, and 1 genotype was susceptible to powdery mildew disease. Among 29 resistant genotypes, BFP77, BFP74, BFP63, BFP62, BFP43, and BFP80 were high yielders and, could be used directly and/or transferred through hybridization to high-yielding disease-susceptible genotypes. Among the 25 moderately resistant genotypes, BFP78, BFP45, BFP79, and BFP48 were found to be high yielders. In principal component analysis (PCA), the first four PCs with Eigen values > 1 accounted for 88.4% variability for quantitative traits. Clustering sorted genotypes into five groups, where groups 1 to 5 assembled 37, 28, 1, 8, and 11 genotypes, respectively. Genotypes of cluster 4 were identified as high yielders with its attributes. Pearson correlation significantly and positively correlated across all traits except for PM. This variation suggested that there is a mechanism to select promising genotypes for field pea breeding. Considering all features, BFP78, BFP77, BFP74, BFP63, BFP62, BFP45, BFP79, and BFP80 could be preferred as high yielders and PM resistance owing to longer pod lengths, seeds per pod and pods per plant.

A kinase fusion protein from Aegilops longissima confers resistance to wheat powdery mildew.

Many disease resistance genes have been introgressed into wheat from its wild relatives. However, reduced recombination within the introgressed segments hinders the cloning of the introgressed genes. Here, we have cloned the powdery mildew resistance gene Pm13, which is introgressed into wheat from Aegilops longissima, using a method that combines physical mapping with radiation-induced chromosomal aberrations and transcriptome sequencing analysis of ethyl methanesulfonate (EMS)-induced loss-of-function mutants. Pm13 encodes a kinase fusion protein, designated MLKL-K, with an N-terminal domain of mixed lineage kinase domain-like protein (MLKL_NTD domain) and a C-terminal serine/threonine kinase domain bridged by a brace. The resistance function of Pm13 is validated through transient and stable transgenic complementation assays. Transient over-expression analyses in Nicotiana benthamiana leaves and wheat protoplasts reveal that the fragment Brace-Kinase122-476 of MLKL-K is capable of inducing cell death, which is dependent on a functional kinase domain and the three α-helices in the brace region close to the N-terminus of the kinase domain.

Stomatal penetration: the cornerstone of plant resistance to the fungal pathogen Zymoseptoria tritici.

BACKGROUND: Septoria tritici blotch (STB), caused by the foliar fungus Zymoseptoria tritici, is one of the most damaging disease of wheat in Europe. Genetic resistance against this fungus relies on different types of resistance from non-host resistance (NHR) and host species specific resistance (HSSR) to host resistance mediated by quantitative trait loci (QTLs) or major resistance genes (Stb). Characterizing the diversity of theses resistances is of great importance for breeding wheat cultivars with efficient and durable resistance. While the functional mechanisms underlying these resistance types are not well understood, increasing piece of evidence suggest that fungus stomatal penetration and early establishment in the apoplast are both crucial for the outcome of some interactions between Z. tritici and plants. To validate and extend these previous observations, we conducted quantitative comparative phenotypical and cytological analyses of the infection process corresponding to 22 different interactions between plant species and Z. tritici isolates. These interactions included four major bread wheat Stb genes, four bread wheat accessions with contrasting quantitative resistance, two species resistant to Z. tritici isolates from bread wheat (HSSR) and four plant species resistant to all Z. tritici isolates (NHR). RESULTS: Infiltration of Z. tritici spores into plant leaves allowed the partial bypass of all bread wheat resistances and durum wheat resistance, but not resistances from other plants species. Quantitative comparative cytological analysis showed that in the non-grass plant Nicotiana benthamiana, Z. tritici was stopped before stomatal penetration. By contrast, in all resistant grass plants, Z. tritici was stopped, at least partly, during stomatal penetration. The intensity of this early plant control process varied depending on resistance types, quantitative resistances being the least effective. These analyses also demonstrated that Stb-mediated resistances, HSSR and NHR, but not quantitative resistances, relied on the strong growth inhibition of the few Z. tritici penetrating hyphae at their entry point in the sub-stomatal cavity. CONCLUSIONS: In addition to furnishing a robust quantitative cytological assessment system, our study uncovered three stopping patterns of Z. tritici by plant resistances. Stomatal resistance was found important for most resistances to Z. tritici, independently of its type (Stb, HSSR, NHR). These results provided a basis for the functional analysis of wheat resistance to Z. tritici and its improvement.

Kosakonia oryziphila NP19 bacterium acts as a plant growth promoter and biopesticide to suppress blast disease in KDML105 rice.

This study demonstrates that root-associated Kosakonia oryziphila NP19, isolated from rice roots, is a promising plant growth-promoting bioagent and biopesticide for combating rice blast caused by Pyricularia oryzae. In vitro experiments were conducted on fresh leaves of Khao Dawk Mali 105 (KDML105) jasmine rice seedlings. The results showed that NP19 effectively inhibited the germination of P. oryzae fungal conidia. Fungal infection was suppressed across three different treatment conditions: rice colonized with NP19 and inoculated by fungal conidia, a mix of NP19 and fungal conidia concurrently inoculated on the leaves, and fungal conidia inoculation first followed by NP19 inoculation after 30 h. Additionally, NP19 reduced fungal mycelial growth by 9.9-53.4%. In pot experiments, NP19 enhanced the activities of peroxidase (POD) and superoxide dismutase (SOD) by 6.1-63.0% and 3.0-67.7%, respectively, indicating a boost in the plant's defense mechanisms. Compared to the uncolonized control, the NP19-colonized rice had 0.3-24.7% more pigment contents, 4.1% more filled grains per panicle, 26.3% greater filled grain yield, 34.4% higher harvest index, and 10.1% more content of the aroma compound 2-acetyl-1-pyrroline (2AP); for rice colonized with NP19 and infected with P. oryzae, these increases were 0.2-49.2%, 4.6%, 9.1%, 54.4%, and 7.5%, respectively. In field experiments, blast-infected rice that was colonized and/or inoculated with NP19 treatments had 15.1-27.2% more filled grains per panicle, 103.6-119.8% greater filled grain yield, and 18.0-35.8% higher 2AP content. A higher SOD activity (6.9-29.5%) was also observed in the above-mentioned rice than in the blast-infected rice that was not colonized and inoculated with NP19. Following blast infection, NP19 applied to leaves decreased blast lesion progression. Therefore, K. oryziphila NP19 was demonstrated to be a potential candidate for use as a plant growth-promoting bioagent and biopesticide for suppressing rice blast.

Genetic diversity and genome-wide association study of partial resistance to Sclerotinia stem rot in a Canadian soybean germplasm panel.

KEY MESSAGE: Developing genetically resistant soybean cultivars is key in controlling the destructive Sclerotinia Stem Rot (SSR) disease. Here, a GWAS study in Canadian soybeans identified potential marker-trait associations and candidate genes, paving the way for more efficient breeding methods for SSR. Sclerotinia stem rot (SSR), caused by the fungal pathogen Sclerotinia sclerotiorum, is one of the most important diseases leading to significant soybean yield losses in Canada and worldwide. Developing soybean cultivars that are genetically resistant to the disease is the most inexpensive and reliable method to control the disease. However, breeding for resistance is hampered by the highly complex nature of genetic resistance to SSR in soybean. This study sought to understand the genetic basis underlying SSR resistance particularly in soybean grown in Canada. Consequently, a panel of 193 genotypes was assembled based on maturity group and genetic diversity as representative of Canadian soybean cultivars. Plants were inoculated and screened for SSR resistance in controlled environments, where variation for SSR phenotypic response was observed. The panel was also genotyped via genotyping-by-sequencing and the resulting genotypic data were imputed using BEAGLE v5 leading to a catalogue of 417 K SNPs. Through genome-wide association analyses (GWAS) using FarmCPU method with threshold of FDR-adjusted p-values < 0.1, we identified significant SNPs on chromosomes 2 and 9 with allele effects of 16.1 and 14.3, respectively. Further analysis identified three potential candidate genes linked to SSR disease resistance within a 100 Kb window surrounding each of the peak SNPs. Our results will be important in developing molecular markers that can speed up the breeding for SSR resistance in Canadian grown soybean.

Life on a leaf: the epiphyte to pathogen continuum and interplay in the phyllosphere.

Epiphytic microbes are those that live for some or all of their life cycle on the surface of plant leaves. Leaf surfaces are a topologically complex, physicochemically heterogeneous habitat that is home to extensive, mixed communities of resident and transient inhabitants from all three domains of life. In this review, we discuss the origins of leaf surface microbes and how different biotic and abiotic factors shape their communities. We discuss the leaf surface as a habitat and microbial adaptations which allow some species to thrive there, with particular emphasis on microbes that occupy the continuum between epiphytic specialists and phytopathogens, groups which have considerable overlap in terms of adapting to the leaf surface and between which a single virulence determinant can move a microbial strain. Finally, we discuss the recent findings that the wheat pathogenic fungus Zymoseptoria tritici spends a considerable amount of time on the leaf surface, and ask what insights other epiphytic organisms might provide into this pathogen, as well as how Z. tritici might serve as a model system for investigating plant-microbe-microbe interactions on the leaf surface.

Genome sequencing and CAZymes repertoire analysis of Diaporthe eres P3-1W causing postharvest fruit rot of 'Hongyang' kiwifruit in China.

Postharvest rot caused by various fungal pathogens is a damaging disease affecting kiwifruit production and quality, resulting in significant annual economic losses. This study focused on isolating the strain P3-1W, identified as Diaporthe eres, as the causal agent of 'Hongyang' postharvest rot disease in China. The investigation highlighted cell wall degrading enzymes (CWDEs) as crucial pathogenic factors. Specially, the enzymatic activities of cellulase, ß-galactosidase, polygalacturonase, and pectin methylesterases peaked significantly on the second day after infection of D. eres P3-1W. To gain a comprehensive understanding of these CWDEs, the genome of this strain was sequenced using PacBio and Illumina sequencing technologies. The analysis revealed that the genome of D. eres P3-1W spans 58,489,835 bp, with an N50 of 5,939,879 bp and a GC content of 50.7%. A total of 15,407 total protein-coding genes (PCGs) were predicted and functionally annotated. Notably, 857 carbohydrate-active enzymes (CAZymes) were identified in D. eres P3-1W, with 521 CWDEs consisting of 374 glycoside hydrolases (GHs), 108 carbohydrate esterase (CEs) and 91 polysaccharide lyases (PLs). Additionally, 221 auxiliary activities (AAs), 91 glycosyltransferases (GTs), and 108 carbohydrate binding modules (CBMs) were detected. These findings offer valuable insights into the CAZymes of D. eres P3-1W.

The Tet-on system for controllable gene expression in the rock-inhabiting black fungus Knufia petricola.

Knufia petricola is a black fungus that colonizes sun-exposed surfaces as extreme and oligotrophic environments. As ecologically important heterotrophs and biofilm-formers on human-made surfaces, black fungi form one of the most resistant groups of biodeteriorating organisms. Due to its moderate growth rate in axenic culture and available protocols for its transformation and CRISPR/Cas9-mediated genome editing, K. petricola is used for studying the morpho-physiological adaptations shared by extremophilic and extremotolerant black fungi. In this study, the bacteria-derived tetracycline (TET)-dependent promoter (Tet-on) system was implemented to enable controllable gene expression in K. petricola. The functionality i.e., the dose-dependent inducibility of TET-regulated constructs was investigated by using GFP fluorescence, pigment synthesis (melanin and carotenoids) and restored uracil prototrophy as reporters. The newly generated cloning vectors containing the Tet-on construct, and the validated sites in the K. petricola genome for color-selectable or neutral insertion of expression constructs complete the reverse genetics toolbox. One or multiple genes can be expressed on demand from different genomic loci or from a single construct by using 2A self-cleaving peptides, e.g., for localizing proteins and protein complexes in the K. petricola cell or for using K. petricola as host for the expression of heterologous genes.

Favorable outcome of Lasiodiplodia theobromae keratomycosis : a clinical case and systematic review.

BACKROUD: Keratitis caused by Lasiodiplodia theobromae is rare and typically associated with a poor prognosis. Current literature lacks sufficient evidence on effective management of patients with this condition. CASE PRESENTATION: A 74-year-old former agricultural worker presented with a red right eye, discomfort, and decreased visual acuity, progressing over three days without treatment. Examination revealed type 2 diabetes and a non-perforating, spiculated corneal abscess with a hypopyon in the right eye. Initial treatment included a triple antibiotic therapy and supportive care. Direct mycological examination identified numerous septate mycelial filaments. Antifungal treatment with natamycin and voriconazole, both topically and orally, was initiated. Cultures confirmed Lasiodiplodia theobromae. The patient showed significant improvement. Treatment continued for eight weeks, with a final visual acuity of 20/50 due to a stromal scar. CONCLUSION: An extensive literature review conducted in November 2023, using databases such as PubMed and Google Scholar with the keywords "lasiodiplodia" and "keratitis" yielded no previous cases of this specific condition being managed solely with the combined use of natamycin and voriconazole. This antifungal combination is commonly included in most management protocols for fungal keratitis. Factors such as the use of corticosteroids and delayed diagnosis were noted to adversely affect the prognosis. This case and this systematic review underscores the potential for non-surgical management options in severe fungal keratitis.

Bioassay-Guided Identification of Natural Products for Biocontrol by Thin Layer Chromatography-Direct Bioautography.

Thin layer chromatography-direct bioautography (TLC-DB) is a well-established bioassay used to separate and identify natural products (NPs) that are antagonistic against a target pathogen. It is a rapid, inexpensive, and simple option for the bioassay-guided isolation and identification of NPs that hinges on separation by TLC coupled with the direct application of a target pathogen to examine bioactivity. It is typically used for the analysis of bioactive plant extracts, detecting inhibitory activity against bacteria, fungi, and enzymes. That being said, it has great potential in bacterial NP discovery, particularly for evaluating bacterial NPs against pertinent agricultural pathogens, which is valuable for discovering and developing novel biopesticides for the agriculture industry. Furthermore, it is a tunable protocol that could be applied to other target pathogens or sources of NPs in research programs concerning the discovery and identification of bioactive compounds. Herein, we describe a model system for discovering and identifying biopesticide NPs using TLC-DB with Bacillus spp. and the agricultural pathogen Sclerotinia sclerotiorum.

Evolution and related pathogenic genes of Pseudodiploöspora longispora on Morchella based on genomic characterization and comparative genomic analysis.

True morels (Morchella) are globally renowned medicinal and edible mushrooms. White mold disease caused by fungi is the main disease of Morchella, which has the characteristics of wide incidence and strong destructiveness. The disparities observed in the isolation rates of different pathogens indicate their varying degrees of host adaptability and competitive survival abilities. In order to elucidate its potential mechanism, this study, the pathogen of white mold disease from Dafang county, Guizhou Province was isolated and purified, identified as Pseudodiploöspora longispora by morphological, molecular biological and pathogenicity tests. Furthermore, high-quality genome of P. longisporus (40.846 Mb) was assembled N50 of 3.09 Mb, predicts 7381 protein-coding genes. Phylogenetic analysis of single-copy homologous genes showed that P. longispora and Zelopaecilomyces penicillatus have the closest evolutionary relationship, diverging into two branches approximately 50 (44.3-61.4) MYA. Additionally, compared with the other two pathogens causing Morchella disease, Z. penicillatus and Cladobotryum protrusum, it was found that they had similar proportions of carbohydrate enzyme types and encoded abundant cell wall degrading enzymes, such as chitinase and glucanase, indicating their important role in disease development. Moreover, the secondary metabolite gene clusters of P. longispora and Z. penicillatus show a high degree of similarity to leucinostatin A and leucinostatin B (peptaibols). Furthermore, a gene cluster with synthetic toxic substance Ochratoxin A was also identified in P. longispora and C. protrusum, indicating that they may pose a potential threat to food safety. This study provides valuable insights into the genome of P. longispora, contributing to pathogenicity research.

Discovery of Benzothiazol-2-ylthiophenylpyrazole-4-carboxamides as Novel Succinate Dehydrogenase Inhibitors.

Succinate dehydrogenase (SDH) has been considered an ideal target for discovering fungicides. To develop novel SDH inhibitors, in this work, 31 novel benzothiazol-2-ylthiophenylpyrazole-4-carboxamides were designed and synthesized using active fragment exchange and a link approach as promising SDH inhibitors. The findings from the tests on antifungal activity indicated that most of the synthesized compounds displayed remarkable inhibition against the fungi tested. Compound Ig N-(2-(((5-chlorobenzo[d]thiazol-2-yl)thio)methyl)phenyl)-3-(difluoromethyl)-1-methyl-1H-yrazole-4-carboxamide, with EC50 values against four kinds of fungi tested below 10 µg/mL and against Cercospora arachidicola even below 2 µg/mL, showed superior antifungal activity than that of commercial fungicide thifluzamide, and specifically compounds Ig and Im were found to show preventative potency of 90.6% and 81.3% against Rhizoctonia solani Kühn, respectively, similar to the positive fungicide thifluzamide. The molecular simulation studies suggested that hydrophobic interactions were the main driving forces between ligands and SDH. Encouragingly, we found that compound Ig can effectively promote the wheat seedlings and the growth of Arabidopsis thaliana. Our further studies indicated that compound Ig could stimulate nitrate reductase activity in planta and increase the biomass of plants.

The Velvet transcription factor PnVeA regulates necrotrophic effectors and secondary metabolism in the wheat pathogen Parastagonospora nodorum.

The fungus Parastagonospora nodorum causes septoria nodorum blotch on wheat. The role of the fungal Velvet-family transcription factor VeA in P. nodorum development and virulence was investigated here. Deletion of the P. nodorum VeA ortholog, PnVeA, resulted in growth abnormalities including pigmentation, abolished asexual sporulation and highly reduced virulence on wheat. Comparative RNA-Seq and RT-PCR analyses revealed that the deletion of PnVeA also decoupled the expression of major necrotrophic effector genes. In addition, the deletion of PnVeA resulted in an up-regulation of four predicted secondary metabolite (SM) gene clusters. Using liquid-chromatography mass-spectrometry, it was observed that one of the SM gene clusters led to an accumulation of the mycotoxin alternariol. PnVeA is essential for asexual sporulation, full virulence, secondary metabolism and necrotrophic effector regulation.

Identification of Biomarkers Associated with Phyllosticta citricarpa Tolerance.

Citrus black spot (CBS) is a fungal disease caused by Phyllosticta citricarpa Kiely, (McAlpine Van der Aa), with most cultivars being susceptible to infection. Currently, disease control is based on the application of protective fungicides, which is restricted due to resistance, health and environmental concerns. Although using natural products for disease management is gaining momentum, more advances are required. This study obtained the metabolic profiles of the essential oil and cuticular waxes of two citrus cultivars with a varying susceptibility to CBS infection using gas chromatography-mass spectrometry. A multivariate data analysis identified possible biomarker compounds that contributed to the difference in susceptibility between the two cultivars. Several identified biomarkers were tested in vitro for their antifungal properties against P. citricarpa. Two biomarkers, propanoic acid and linalool, were able to completely inhibit pathogen growth at 750 mg/L and 2000 mg/L, respectively.