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The HOG MAPK pathway mediates diverse cellular and physiological processes, including osmoregulation and fungicide sensitivity, in phytopathogenic fungi. However, the molecular mechanisms underlying HOG MAPK pathway-associated stress homeostasis and pathophysiological developmental events are poorly understood. Here, we demonstrated that the oxalate decarboxylase CsOxdC3 in Colletotrichum siamense interacts with the protein kinase kinase CsPbs2, a component of the HOG MAPK pathway. The expression of the CsOxdC3 gene was significantly suppressed in response to phenylpyrrole and tebuconazole fungicide treatments, while that of CsPbs2 was upregulated by phenylpyrrole and not affected by tebuconazole. We showed that targeted gene deletion of CsOxdC3 suppressed mycelial growth, reduced conidial length, and triggered a marginal reduction in the sporulation characteristics of the Δ CsOxdC3 strains. Interestingly, the Δ CsOxdC3 strain was significantly sensitive to fungicides, including phenylpyrrole and tebuconazole, while the CsPbs2 -defective strain was sensitive to tebuconazole but resistant to phenylpyrrole. Additionally, infection assessment revealed a significant reduction in the virulence of the Δ CsOxdC3 strains when inoculated on the leaves of rubber tree (Hevea brasiliensis). From these observations, we inferred that CsOxdC3 crucially modulates HOG MAPK pathway-dependent processes, including morphogenesis, stress homeostasis, fungicide resistance, and virulence, in C. siamense by facilitating direct physical interactions with CsPbs2. This study provides insights into the molecular regulators of the HOG MAPK pathway and underscores the potential of deploying OxdCs as potent targets for developing fungicides. [ABSTRACT FROM AUTHOR]

Colletotrichum fructicola is a globally significant phytopathogenic fungus. Mycovirus-induced hypovirulence has great potential for biological control and study of fungal pathogenic mechanisms. We previously reported that the mycovirus Colletotrichum alienum partitivirus 1 (CaPV1) is associated with the hypovirulence of C. fructicola , and the present study aimed to further investigate a host factor and its roles in mycovirus-induced hypovirulence. A gene named CfKOB1 , which encodes putative protein homologous to the β-subunit of voltage-gated potassium channels and aldo–keto reductase, is downregulated upon CaPV1 infection and significantly upregulated during the early infection phase of Nicotiana benthamiana by C. fructicola. Deleting the CfKOB1 gene resulted in diminished vegetative growth, decreased production of asexual spores, hindered appressorium formation, reduced virulence, and altered tolerance to abiotic stresses. Transcriptome analysis revealed that CfKOB1 regulates many metabolic pathways as well as the cell cycle and apoptosis. Furthermore, enhanced apoptosis was observed in the Δ CfKOB1 mutants. Viral RNA accumulation was significantly increased in the CfKOB1 deletion mutant. Additionally, our findings demonstrated that CaPV1 infection in the WT strain also induced cell apoptosis. Collectively, these results highlight the diverse biological roles of the CfKOB1 gene in the fungus C. fructicola , while it also participates in mycovirus-induced hypovirulence by regulating apoptosis. • A gene named CfKOB1 was confirmed to regulate development and pathogenicity of C. fructicola. • The CfKOB1 gene is downregulated upon mycovirus CaPV1 infection. • Deletion of CfKOB1 enhances cell apoptosis of C. fructicola. • CfKOB1 plays a negative role in viral RNA accumulation in the CaPV1 infected host fungus. • CfKOB1 associated cell apoptosis participates in mycovirus-induced hypovirulence in C. fructicola. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria, such as Bacillus spp., establish beneficial associations with plants and may inhibit the growth of phytopathogenic fungi. However, these bacteria are subject to multiple biotic stimuli from their competitors, causing stress and modifying their development. This work is a study of an in vitro interaction between two model microorganisms of socioeconomic relevance, using population dynamics and transcriptomic approaches. Co-cultures of Bacillus velezensis 83 with the phytopathogenic fungus Colletotrichum gloeosporioides 09 were performed to evaluate the metabolic response of the bacteria under conditions of non-nutritional limitation. The bacterial response was associated with the induction of a stress-resistant phenotype, characterized by a lower specific growth rate, but with antimicrobial production capacity. About 12% of co-cultured B. velezensis 83 coding sequences were differentially expressed, including the up-regulation of the general stress response (sigB regulon), and the down-regulation of alternative carbon sources catabolism (glucose preference). Defense strategies in B. velezensis are a determining factor in order to preserve the long-term viability of its population. Mostly, the presence of the fungus does not affect the expression of antibiosis genes, except for those corresponding to surfactin/bacillomycin D production. Indeed, the up-regulation of antibiosis genes expression is associated with bacterial growth, regardless of the presence of the fungus. This behavior in B. velezensis 83 resembles the strategy used by the classical Greek phalanx formation: by sacrificing growth rate and metabolic versatility, resources can be redistributed to defense (stress resistant phenotype) while maintaining the attack (antibiosis capacity). The presented results are the first characterization of the molecular phenotype at the transcriptome level of a biological control agent under biotic stress caused by a phytopathogen without nutrient limitation. [Display omitted] • Study of in vitro interaction between B. velezensis and C. gloeosporioides. • Colletotrichum modify growth rate and gene expression in Bacillus population. • Co-cultured Bacillus increased expression of SigB regulon as defense mechanism. • Up-expression of antibiosis-related genes is growth-associated. • Bacillus biocontrol strategy consist in a stress-resistant phenotype with antibiosis. [ABSTRACT FROM AUTHOR]

Two homologous gene clusters for the biosynthesis of sesterterpenes betaestacins were identified from two phytopathogens, Phoma betae and Colletotrichum orbiculare . Heterologous expression of identified oxidation enzymes with previously-characterized PbTS1 (BtcA Pb ) resulted in the production of seven novel sesterterpenes. Although both strains possessed homologous enzymes, oxidation state of corresponding products were different from each other, suggesting that structural diversification of sesterterpene skeletons might be achieved by these homologous enzymes with different functions. [ABSTRACT FROM AUTHOR]

Based on the microwave-assisted synthetic protocol developed in our previous work, we have synthesized a series of novel furo[3,2- c ]coumarins as fused Osthole derivatives, via the reaction of 4-hydroxycoumarins and β -ketoesters catalyzed by DMAP. All the target compounds were evaluated in vitro for their antifungal activity against six phytopathogenic fungi, some compounds exhibited potential activity in the primary assays. Especially compounds 6c , 7b , 8b and 8c (shown in Fig. 1) were the most active ones, EC 50 values of these four compounds against Colletotrichum capsica , Botrytis cinerea and Rhizoctonia solani were further investigated. 6c was identified as the most promising candidate with the EC 50 value at 0.110 μM against Botrytis cinerea and 0.040 μM against Colletotrichum capsica , respectively, representing better antifungal activity than that of the commonly used fungicide Azoxystrobin. [ABSTRACT FROM AUTHOR]

Avocado is an economically important fruit that is severely affected by anthracnose disease due to the infection with Colletotrichum spp. In this study, avocado fruits with anthracnose symptoms were collected in Morelos, Mexico. Two phytopathogenic fungi were isolated from these fruits and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum using ITS sequences. Further, eleven yeasts from avocado (three from fruits, four from leaves and four from rhizospheric soil) were isolated; of which three showed in vitro antagonistic activity against C. gloeosporioides and C. acutatum . ITS sequence analysis of the isolated yeasts revealed that the strains obtained from fruits belonged to Candida intermedia while those isolated from leaves belonged to Wickerhamomyces anomalus . C. intermedia reduced disease incidence caused only by C. gloeosporioides , whereas, W. anomalus caused a significant reduction in the incidence and severity of disease caused by both C. gloeosporioides and C. acutatum . To the best of our knowledge, this is the first report on the antagonistic activity of W. anomalus or C. intermedia against Colletotrichum acutatum. Thus, W. anomalus is a potential natural alternative for controlling anthracnose infection and associated loss in avocado crops. [ABSTRACT FROM AUTHOR]

A new standardized method, using isothermal microcalorimetry (IMC), was established to determine thermokinetic parameters from heat flow curves and to demonstrate the reproducibility and repeatability of the parameters of five Colletotrichum species on different days. Measurements on IMC were made at different periods and by two operators. Repeatability and reproducibility (R&R) measurement system analysis was performed on the technique used to measure the heat flow of Colletotrichum strains. The results showed that the %GageR&R was found to be within the acceptable ranges of a measurement system. Also, the parameters obtained from the curves were subjected to a combination of Principal Component Analysis (PCA) and Clustering, the data showed that the total heat (H t) and maximum growth rate (μ max) are probably the most specific distinguishing characteristic of the strains evaluated in this study. This study demonstrates, for the first time, the usefulness of IMC in obtaining heat flow curves and thermokinetic parameters, providing repeatable and reproducible measurements over a period and under controlled conditions, for future identifications of phytopathogenic fungi. • Colletotrichum sp. characterization method by microcalorimetry was standardized • Heat flow measurements were repeatable and reproducible over time • Thermokinetic parameters were obtained from the integrated heat flow curves • Thermokinetic parameters discriminated fungi through PCA analysis • This is the first report on microcalorimetry usefulness for fungi identification [ABSTRACT FROM AUTHOR]

The present work aimed to evaluate the defense responses induced by chemically sulfated ulvans in Arabidopsis thaliana plants against the phytopathogenic fungi Alternaria brassicicola and Colletotrichum higginsianum . Derivatives with growing sulfate content (from 20.9 to 36.6%) were prepared with SO 3 -pyridine complex in formamide. NMR and FTIR spectroscopic analyses confirmed the increase of sulfate groups after the chemical sulfation process. The native sulfated polysaccharide (18.9% of sulfate) and its chemically sulfated derivatives similarly reduced the severity of both pathogenic fungi infections. Collectively, our results suggest that ulvans induce resistance against both fungal pathogens independently of its sulfation degree. [ABSTRACT FROM AUTHOR]

A series of new Fangchinoline derivatives with the carbamate moiety (compounds 1a - 1l , 2a - 2l) were synthesized by utilizing phenolic hydroxyl to react with isocyanate. The potential fungicidal activity of all the target compounds has been screened against six species of plant pathogen fungi, including Pp. adianticola (Phomopsis adianticola), A. adianticola (Altermaria adianticola), C. fructicola (Colletotrichum fructicola), P. theae (Pestalotiopsis theae), P. adianticola (Phoma adianticola), and G. zeae (Gibberella zeae). Almost all the derivatives showed better fungicidal activity than Fangchinoline. Compounds 1f, 1g , 1h , and 1k exhibited obviously better activity against G. zeae , and Pp. adianticola than Azoxystrobin. Especially compounds 1k displayed high fungicidal activity against G. zeae , Pp. adianticola , and P. theae. [ABSTRACT FROM AUTHOR]

Coffee cultivation around the world is affected by phytopathogenic fungi, among them Colletotrichum sp., the causative agent of anthracnose. In the present work, therefore, an in vitro study was carried out on the antifungal effect of zinc oxide nanoparticles (ZnO-NPs) obtained by a chemical route on Colletotrichum sp. To this end, the area of growth of the fungus exposed to the action of concentrations of 9 mmolL−1 (730 ppm), 12 mmolL−1 (980 ppm), and 15 mmolL−1 (1200 ppm) of ZnO-NPs was monitored and their behavior was compared with the effect of the fungicide, ciproconazole (positive control) as well as with a sample of the fungus that grew normally (negative control). The ZnO-NPs showed an appreciable percent inhibition of fungal growth, ~96% for the concentration of 15 mmolL−1 at 6 days, causing loss in the continuity of some hyphae and the formation of groups of hyphal structures. Additionally, the ZnO-NPs favored the formation of structures of compact appearance (similar to vacuoles) within the hypha, as well as decreasing the cytoplasmic space. Image 1 • The antifungal activity of ZnO nanoparticles on Colletotrichum spp. was evaluated. • The micro and ultrastructural effects of the ZnO-NPs over fungi were analized. • The evaluated ZnO-NPs significantly inhibited the growth of the Colletotrichum spp. • The synthesized ZnO nanoparticles could potentially be used to protect coffee crops. [ABSTRACT FROM AUTHOR]