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Anthracnose disease, caused by the Colletotrichum gloeosporioides species, affects vegetables, fruits, pulses, and cereals, leading to significant economic losses worldwide. Although many synthetic fungicides are used to control this pathogen, eco-friendly biological alternatives are gaining popularity. This study focuses on isolating and purifying chitinase (Af Chi)from a marine bacterium and testing its antifungal efficacy against C. gloeosporioides spore germination by targeting the chitin in the fungal cell wall. The chitinase was purified from a marine bacterium A. faecalis from the Arabian Sea and had a molecular mass of 45 kDa and a specific activity of 84.6 U/mg. Af Chi worked best at 50 °C and pH 7.0 in Tris HCl buffer. Na+ ion was the highest cofactor, highlighting the halophilic nature of this chitinase. K+, Ca2+, Cu2+, Mg2+, Mn2+, and EDTA also increased activity, while Fe3+, Zn2+, Co2+, and Pb2+ decreased it. The Km and Vmax values were 1.87 µg/mL and 17.45 U/mL, respectively. Purified Af Chi at 10 mg/mL completely inhibited spore germination within 8 h and reduced the size of the spores. Key points: The chitinase remain stable at high temperature. The chitinase from A. faecalis shown positive result in development of natural bio-fungicide. [ABSTRACT FROM AUTHOR]

A new lactone, collectindolide (1), as well as three known compounds, (S)-sydonic acid (2), (S)-hidroxysydonic acid (3), and indole-3-aceticacid (4) were obtained from the liquid media of Colletotrichum gloeosporioides, which was obtained from Artocarpus heterophyllus. The chemical structures of 1-4 were established by spectroscopic analyses, including NMR experiments and by HR-ESI-TOF-MS mass spectroscopy. Compounds 1-4 were evaluated for their cytotoxicity against murine leukaemia P-388 cell lines by MTT assay. Antibacterial activity of compounds 1-4 was also assayed against four bacteria. Phytochemical investigation of the genus Colletotrichum derived from the plant genus Artocarpus is reported for the first time. [ABSTRACT FROM AUTHOR]

In Mexico, the Ataulfo mango crop faces significant challenges due to anthracnose, a disease caused by the fungus Colletotrichum gloeosporioides. The need to use eco-friendly fungicides is crucial to avoid the use of harmful synthetic chemicals. This study aimed to prepare chitosan nanoparticles through a simple and effective ultrasound-assisted top-down method, with high antifungal efficiency. The nanoparticles were prepared from chitosan (DD = 85%, MW = 553 kDa) and Tween 20 under constant sonication. The formation of the nanoparticles was initially confirmed by Fourier-transform infrared (FTIR) spectroscopy; and their physicochemical properties were subsequently characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The antifungal potential of the chitosan nanoparticles against the phytopathogen Colletotrichum gloeosporioides was evaluated with isolated fungi obtained directly from mango tissues showing anthracnose symptoms in the state of Guerrero, Mexico. The fungus was identified through SEM imaging, showing a regular and smooth conidial layer, with cylindrical shape (r = 2 µm, h = 10 µm). In vitro tests were conducted with three different concentrations of chitosan nanoparticles to assess their inhibitory effects. After seven days of incubation, a maximum inhibition rate of 97% was observed with the 0.5% nanoparticle solution, corresponding to a fungal growth rate of 0.008 cm/h. At this time, the control mycelial growth was 7 cm, while the treated sample reached a radius of 0.55 mm. These results demonstrated the antifungal effect of the nanoparticles on the membrane and cell wall of the fungus, suggesting that their composition could induce a resistance response. The inhibitory effect was also influenced by the particle size (30 nm), as the small size facilitated penetration into fungal cells. Consequently, the parent compound could be formulated and applied as a natural antifungal agent in nanoparticle form to enhance its activity. The method described in this study offers a viable alternative for the preparation of chitosan nanoparticles, by avoiding the use of toxic reagents. [ABSTRACT FROM AUTHOR]

Walnut (Juglans spp.), a significant deciduous tree of economic and ecological importance, faces substantial threats from walnut anthracnose, primarily caused by Colletotrichum gloeosporioides. Bacillus velezensis has shown promise in mitigating this fungal pathogen. To delve deeper into the induction mechanism of B. velezensis on walnut plant resistance, we conducted a metabolomic analysis on walnut leaves from six different treatment groups. Specifically, the groups were defined as follows: Group B.v. was inoculated with B. velezensis alone, Group CK served as the blank control, and Group C.g. was inoculated solely with C. gloeosporioides. Group B.v.-C.g. received B. velezensis followed by C. gloeosporioides inoculation. Group B.v.+C.g. underwent simultaneous inoculation with both B. velezensis and C. gloeosporioides, while Group C.g.-B.v. was treated first with C. gloeosporioides then B. velezensis. A total of 1,503 metabolites were detected, mainly including flavonoids, terpenoids, and steroids. The results revealed that B. velezensis spraying not only enhanced the inherent resistance of walnut plants but also significantly regulated walnut plants already infected with C. gloeosporioides. This was mainly achieved by inducing walnut plants to adjust their metabolic pathways such as salicylic acid, jasmonic acid, and abscisic acid, thereby strengthening their stress response. Transcriptomic and metabolomic correlation analyses showed that in the comparisons of B.v. vs. CK, C.g. vs. CK, and C.g.-B.v. vs. C.g., 59, 244, and 122 differential abundance metabolites were detected, along with 7860, 3677, and 5587 differential genes, respectively. Amino acid synthesis, starch and sucrose metabolism, photosynthesis, phenylpropane metabolism, purine metabolism, and glutathione metabolism played crucial roles in walnut's disease resistance mechanism. Further analysis revealed that B. velezensis induced walnut plants to regulate multiple genes, such as LOC109005403, LOC108985444 and LOC118344177, resulting in the production of defensive metabolites such as palmitic acid, coumarin and ferulic acid, thereby enhancing their resistance to C. gloeosporioides. In summary, B. velezensis induces systemic resistance in walnut plants by modulating the metabolic pathways of salicylic acid, jasmonic acid, and abscisic acid. It enhances this resistance by strengthening cell walls, synthesizing defensive secondary metabolites, and regulating energy metabolism and stress responses. These findings provide a solid theoretical foundation for the future field application of B. velezensis in controlling walnut anthracnose. [ABSTRACT FROM AUTHOR]

Summary: Apple is an important cash crop in China, and it is susceptible to fungal infections that have deleterious effects on its yield. Apple bitter rot caused by Colletorichum gloeosporioides is one of the most severe fungal diseases of apple. Salicylic acid (SA) is a key signalling molecule in the plant disease resistance signalling pathways. Lignin synthesis also plays a key role in conferring disease resistance. However, few studies have clarified the relationship between the SA disease resistance signalling pathway and the lignin disease resistance pathway in apple. MdMYB46 has previously been shown to promote lignin accumulation in apple and enhance salt and osmotic stress tolerance. Here, we investigated the relationship between MdMYB46 and biological stress; we found that MdMYB46 overexpression enhances the resistance of apple to C. gloeosporioides. We also identified MdARF1, a transcription factor upstream of MdMYB46, via yeast library screening and determined that MdARF1 was regulated by miR7125 through psRNATarget prediction. This regulatory relationship was confirmed through LUC and qRT‐PCR experiments, demonstrating that miR7125 negatively regulates MdARF1. Analysis of the miR7125 promoter revealed that miR7125 responds to SA signals. The accumulation of SA level will result in the decrease of miR7125 expression level. In sum, the results of our study provide novel insights into the molecular mechanisms underlying the resistance of apple to C. gloeosporioides and reveal a new pathway that enhances lignin accumulation in apple in response to SA signals. These findings provide valuable information for future studies aimed at breeding apple for disease resistance. [ABSTRACT FROM AUTHOR]

One of the most important phytosanitary diseases affecting the production and marketing of the 'Hass' avocado fruit is anthracnose, mainly caused by the fungus Colletotrichum gloeosporioides. This disease is controlled with synthetic fungicides, which can cause harm to humans and the environment. Due to this, safer alternatives have been sought, such as biological control. The objective of this study was to isolate and characterize Bacillus spp. strains that biocontrol C. gloeosporioides in 'Hass' avocado fruits. The isolation, purification, and molecular identification of bacteria with biocontroller capacity was carried out. In vitro and in vivo tests were carried out against the pathogen C. gloeosporioides. Furthermore, the percentage inhibition of spore germination, enzymatic profile, and nutrient assimilation were determined. Forty-three native bacterial strains were isolated from the 'Hass' avocado fruit. The strains that showed the greatest antagonistic capacity in vivo against C. gloeosporioides were Bacillus pumilus AB31, B. thuringiensis AB30, B. thuringiensis AB7, and B. thuringiensis AB21. These strains could produce extracellular enzymes, such as phosphatases, proteases, and β-glucosidase, as well as the assimilation of D-ribose and trehalose. The above favors their antagonistic activity. Four strains of the genus Bacillus (one B. pumilus and three B. thuringiensis) can control C. gloeosporioides in 'Hass' avocado. [ABSTRACT FROM AUTHOR]

The microencapsulated yeast Meyerozyma guilliermondii LMA-Cp01 has previously shown high efficacy under laboratory tests against mango anthracnose caused by Colletotrichum gloeosporioides. Infection by C. gloeosporioides occurs in the field; therefore, it could be advantageous to apply the formulation at preharvest, which would reduce initial infection and control the pathogens. This work aimed to evaluate the effectiveness of free and two doses of microencapsulated M. guilliermondii applied in preharvest (four applications between early flowering and harvest) and one in postharvest to control mango anthracnose in two grown seasons. Besides, the effect of the treatments on quality parameters of mango fruit was also analyzed, as well as the quantification of the antagonist populations after its application on flowers and fruit. Preharvest applications of free and encapsulated M. guilliermondii significantly reduced anthracnose incidence and severity on fruit. M. guilliermondii microcapsules at 107 CFU mL−1 was as effective as fresh cells at 108 CFU mL−1. In orchard two, both doses of microcapsules were more effective than free cells and Captan, and no statistical differences between microcapsules and Benomyl were observed. The postharvest application was less effective in controlling mango anthracnose than preharvest. Under field conditions, LMA-Cp01 populations were higher on flowers and fruit treated with microencapsulated yeast than the free cells. Efficacy of M. guilliermondii was not improved by postharvest applications. Treatments did not adversely affect the quality parameters of mango. Microencapsulated M. guilliermondii LMA-Cp01 is a promising formulation to manage mango anthracnose through preharvest treatments. [ABSTRACT FROM AUTHOR]

Olive tree anthracnose is caused by infection with Colletotrichum fungi, which in Portugal are mostly C. nymphaeae, C. godetiae, and C. gloeosporioides s.s. Severe economic losses are caused by this disease that would benefit from a greener and more efficient alternative to the present agrochemical methods. Yeasts are serious candidates for pre-harvest/in field biocontrol of fungal infections. This work identified the yeast Wickerhamomyces anomalus as a strong antagonizer of the three fungi and studied in vitro this ability and its associated mechanisms. Antagonism was shown to not depend on the secretion of volatile compounds (VOCs), or siderophores or any other agar-diffusible compound, including hydrolytic enzymes. Rather, it occurred mostly in a cell-to-cell contact dependent manner. This was devised through detailed microscopic assessment of yeast-fungus cocultures. This showed that W. anomalus antagonism of the three Colletotrichum proceeded through (i) the adhesion of yeast cells to the phytopathogen hyphae, (ii) the secretion of a viscous extracellular matrix, and (iii) the emptying of the hyphae. Yeasts ultimately putatively feed on hyphal contents, which is supported by light microscopy observation of MB and PI co-culture-stained samples. Accordingly, numerous W. anomalus cells were observed packing inside C. godetiae emptied hyphae. This behaviour can be considered microbial predation and classified as necrotrophic mycoparasitism, more explicitly in the case of C. godetiae. The results support the prospect of future application of W. anomalus as a living biofungicide/BCA in the preharvest control of olive anthracnose. [ABSTRACT FROM AUTHOR]

Background: DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L). Results: In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection. Conclusions: Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs. [ABSTRACT FROM AUTHOR]

Citrus diseases caused by fungal pathogens drastically decreased the yield and quality of citrus fruits, leading to huge economic losses. Given the threats of chemical pesticides on the environment and human health, biocontrol agents have received considerable attention worldwide as ecofriendly and sustainable alternative to chemical fungicides. In the present study, we isolated a Bacillus velezensis strain TZ01 with potent antagonistic effect against three citrus pathogenic fungi: Diaporthe citri, Colletotrichum gloeosporioides and Alternaria alternata. The culture supernatant of this strain exhibited remarkable antifungal activity on potato dextrose agar plates and detached leaves of five citrus varieties. Treatment with TZ01 culture supernatant obviously affected the hyphal morphology and caused nucleic acid leakage. The crude lipopeptides (LPs) extracted from the culture supernatant were found as the major active ingredients, and could maintain the activity under a wide range of temperature and pH and ultraviolet radiation. Furthermore, the type of LPs, produced in vitro, were explored. Whole-genome sequencing of TZ01 revealed secondary metabolite gene clusters encoding synthetases for non-ribosomal peptides and polyketide production, and gene clusters responsible for the synthesis of three important LPs (surfactin, iturin, and fengycin) were identified in the genome. The liquid chromatography-mass spectrometry analysis confirmed the presence of various homologs of surfactin A, bacillomycin D, and fengycin A in the extracted LPs. Taken together, these results contribute to the possible biocontrol mechanisms of B. velezensis strain TZ01, as well as providing a promising new candidate strain as a biological control agent for controlling citrus fungal pathogens. [ABSTRACT FROM AUTHOR]

Introduction: Camellia anthracnose is caused by multiple Colletotrichum species, resulting in severe yield losses of oil-tea Camellia. Colletotrichum fructicola is one of the major anthracnose pathogens of oil-tea Camellia worldwide. However, developing unique molecular markers for the rapid and accurate detection of Colletotrichum fructicola from diverse Colletotrichum species, as well as early monitoring and effective control of the disease, remains largely unexplored. Methods: C. fructicola-specific genes were obtained using a BLAST search of the sequences of predicted genes in C. fructicola against the genome sequences of Colletotrichum fungal pathogens. In this study, Colletotrichum fructicola- specific molecular markers were developed for rapid and accurate detection of C. fructicola among Camellia anthracnose causing fungal pathogens. Results: Using genomic DNA-based end-point PCR and qPCR, three C. fructicola-specific genes with the ability to distinguish C. fructicola from other oil-tea Camellia anthracnose-related Colletotrichum species, including Colletotrichum camelliae, Colletotrichum gloeosporioides, and Colletotrichum siamense, and oil-tea Camellia fungal pathogens belonging to the genus Neopestalotiopsis, Pestalotiopsis, and Alternaria, were validated as molecular markers. In addition, these three molecular markers were highly sensitive to detecting C. fructicola using DNA extracted fromthe inoculated leaves of oil-tea Camellia. Discussion: These findings enable us to rapidly and uniquely detect the Camellia anthracnose disease caused by Colletotrichum fructicola, which will equip farmers with an effective tool for monitoring Camellia anthracnose disease in the field and taking timely control measurements in advance. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides is the causal agent of poplar anthracnose, which induces major economic losses and adversely affects the ecosystem services of poplar forests. The appressorium serves as a penetration structure for many pathogenic fungi, including C. gloeosporioides. The production of mucilage and the formation of penetration pegs are critically important for the appressorium-mediated penetration of host tissues. We previously found that CgPmk1 is a key protein involved in appressorium formation, penetration, and pathogenicity. Although CgSte12, which is a transcription factor that functions downstream of CgPmk1, regulates the formation of penetration pegs, its role in C. gloeosporioides appressorium development and pathogenicity has not been elucidated. Here, we developed C. gloeosporioides CgSTE12 mutants and characterized the molecular and cellular functions of CgSTE12. The results showed that mycelial growth and morphology were not affected in the CgSTE12 knockout mutants, which produced normal melanized appressoria. However, these mutants had less mucilage secreted around the appressoria, impaired appressorial cone formation, and the inability to form penetration pores and pegs, which ultimately led to a significant loss of pathogenicity. Our comparative transcriptome analysis revealed that CgSte12 controls the expression of genes involved in appressorium development and function, including genes encoding cutinases, NADPH oxidase, spermine biosynthesis-related proteins, ceramide biosynthesis-related proteins, fatty acid metabolism-related proteins, and glycerophospholipid metabolism-related proteins. Overall, our findings indicate that CgSte12 is a critical regulator of appressorium development and affects C. gloeosporioides pathogenicity by modulating the structural integrity of appressoria. [ABSTRACT FROM AUTHOR]

Synthetic fungicides are used to control anthracnose caused by Colletotrichum gloeosporioides; however, their frequent application increases the risk of pathogen resistance, environmental damage, and health concerns. It has been reported that caprylic acid (CA) inhibits the in vitro development of C. gloeosporioides; however, its antifungal mechanism and in vivo antifungal potential are still unknown. Therefore, the present work aims to analyse the effect of a CA‐enriched sub‐fraction (CAES) extracted from Vitex mollis fruit on the fungal microstructure by confocal fluorescence microscopy and morphometric analysis. Moreover, the effect of CAES on anthracnose development and quality parameters in papaya fruit was evaluated. The confocal microscopy images confirmed that CAES damaged the cell wall of conidia, given their decreased width. The increased fluorescence intensity in the CAES and CA‐treated mycelium suggested they were attached to the plasma membrane. These treatments produced structural alterations of the vacuoles and septa in mycelium, while in the fungicide thiabendazole (TBZ) treatment, apoptotic bodies appeared. CAES at 1.0 g L−1 had the best effect against anthracnose incidence and severity in papaya fruit, whereas TBZ was only effective on anthracnose severity. None of the applied treatments affected the fruit quality parameters. Therefore, CAES may be develop as an effective option to suppress anthracnose on papaya fruit. [ABSTRACT FROM AUTHOR]

Species of the genus Colletotrichum are among the most important plant pathogens globally, as they are capable of infecting many hosts—apple (Malus spp.) and other fruit and woody plant species—but also vegetable crops, cereals, legumes, and other annual and perennial herbaceous plants. The apple (Malus spp.) is attacked by various species from the genus Colletotrichum, whereby 27 different species from this genus have been described as the causative agents of apple bitter rot (ABR) and 15 as the cause of Glomerella leaf spot (GLS). These species generally belong to one of three species complexes: Colletotrichum acutatum, Colletotrichum gloeosporioides, and Colletotrichum boninense. The largest number of apple pathogens of the genus Colletotrichum belong to the species complex C. acutatum and C. gloeosporioides. However, further data on these species and the interactions between the species complexes of the genus Colletotrichum that cause these two apple diseases is needed for the development of effective control measures, thus ensuring successful and profitable apple cultivation. To contribute to this endeavor, a comprehensive review of the causative agents of ABR and GLS from the genus Colletotrichum is provided. In addition to presenting the species' current names, distribution, economic significance, and the symptoms they cause in apple, their development cycle, epidemiology, and molecular detection strategies are described, with a particular emphasis on control measures. [ABSTRACT FROM AUTHOR]

Plant endophytic microbial communities consist of many latent plant pathogens and, also, many pathogen-related species with reduced virulence. Though with a long history of co-evolution, the diversity and composition of the endophytic mycobiota, especially the pathogen-related fungal groups, has been under-investigated in Citrus (C.). Based on the amplicon sequencing of fungal internal transcribed spacer (ITS), the leaf endophytic mycobiota were profiled on citrus varieties from different citrus-producing regions. The pomelo variety shared significantly distinctive leaf mycobiota when compared to the mandarin and sweet orange; these conform to their host genetic relationships. In addition, a data set of 241 citrus-related fungi, including 171 (71%) pathogens and potential pathogens, was summarized from previous studies. Under the criteria of local BLAST (covered ITS nucleotide ≥ 150 bp, sequence identity ≥ 99%), a total of 935 fungal operational taxonomic units (OTUs) were assigned to 62 pathogen-related fungal groups, representing 14.9% of the relative abundance in the whole community. Of which, the top groups consisted of Colletotrichum gloeosporioides (mean relative abundance, 4.3%), Co. citricola and Co. karstii (2.7%), Zasmidium citri-griseum (2.4%), and Z. fructigenum (1.4%). At the genus level, the ratio of the pathogen-related fungal groups in 64% of fungal genera (16 out of 25) exceeded 50%, which are the solely or mainly occurring fungi of their genus in citrus. Our study suggests that the leaf endophytic compartment may be an important place for the growth of latent pathogens. [ABSTRACT FROM AUTHOR]

Crop disease often leads to field epidemics with serious threats to yield. Early symptoms are sometimes difficult to identify, so the origin of primary inoculum is a critical focal point in the study of plant diseases, as it can help design management strategies to reduce crop losses. Here, we investigated whether anthracnose of water yams (Dioscorea alata L.) caused by the species complex Colletotrichum gloeosporioides can start from infected seed tubers from the previous harvest. Over two years, we collected tubers with varying pathogen prevalence in the field directly from producers and conducted fungal isolations in the lab to sample C. gloeosporioides. We also proceeded to artificially inoculate tubers before planting and monitored disease development. Finally, we genotyped isolates from leaves in the fields and assessed fixation indices between plots based on plot ownership (plots with a common seed tuber origin from a single farmer) vs. samples in plots from unrelated producers in Guadeloupe, Martinique, and Barbados. We were unable to isolate the fungus from harvested tubers in either sampling survey nor did any plants grown from inoculated tubers develop any disease symptoms during growth. Also, the genetic structure of samples within each plot was independent of plot ownership, though this occurred with varying levels in the different islands. These results suggest that contaminated planting material from seed tubers is not the primary source of the disease, which is in contrast to the common perception of yam anthracnose prevalence in the Antilles. [ABSTRACT FROM AUTHOR]

Summary: Food pathogens are one of the microbiological problems that have negative effects on both economic and human health by causing spoilage and decay of important foods such as fruits and vegetables. The adverse effects of chemical residues left by synthetic biocides on human health and the development of resistance mechanisms in microorganisms have directed research towards bio‐fungicide. This study aimed to develop an effective bio‐fungicide using varying concentrations of ethyl pyruvate (1–18 μL disc−1). Additionally, the interaction of EP with several proteins in pathogenic bacteria and fungi was investigated through in silico molecular docking. According to the obtained results, an increase in EP concentration resulted in larger inhibition zone diameters. In this context, at an EP concentration of 18 μL disc−1, the inhibition zones formed against E. coli, S. aureus, L. monocytogenes and S. typhimurium bacteria were measured as 27.50 ± 0.50 mm, 31.00 ± 1.00 mm, 30.00 ± 1.00 mm and 32.66 ± 1.15 mm, respectively. EP at a concentration of 9 μL disc−1 showed a fungicidal effect against B. cinerea and P. expansum and a fungistatic effect against C. gloeosporioides. As a result of in silico tests, the molecular binding energies of EP with E. coli dihydrofolate reductase, S. aureus DNA Gyrase B and B. cinerea 14 alpha‐demethylase were determined to be −4.62, −4.26 and −3.95 kcal mol−1, respectively. Our results holistically revealed that EP has great potential for use in food preservation due to its antifungal and antibacterial properties. [ABSTRACT FROM AUTHOR]

• Citrus anthracnose in Indonesia caused by C. gloeosporioides species complex. • Colletotrichum spp. multigene analysis based on Actin, β-tubulin, and GAPDH genes. • C. gloeosporioides , C. endophytichum , C. queenslandicum caused citrus anthracnose. • First report of C. endophytichum , C. queenslandicum in Indonesia. Citrus (Citrus spp.), including orange as an important one, has a high economic value and significant role both in global market as well as in Indonesia. However, citrus anthracnose caused by Colletotrichum spp. constantly becomes a limiting factor in citrus production. Nevertheless, there is no report on molecular basis about the species associates to the citrus anthracnose in Indonesia up to date. Therefore, this research aims to identify the isolates of Colletotrichum spp. based on polyphasic approach which combining morphological character, pathogenicity and multigene analysis using actin, β-tubulin, and GAPDH primers. Twenty-two isolates were obtained from leaves and citrus fruits with anthracnose symptoms which showed various morphological characteristics, both macroscopic and microscopic. Pathogenicity test results showed that all 22 isolates were virulent to Keprok Batu 55 orange and California lemon. The anthracnose symptoms produced are identical to the symptoms in the field, however the symptoms on the California lemon were milder than on the Keprok Batu 55 mandarin. The results of multigene analysis showed that there were three species causing citrus anthracnose in Indonesia, which were C. endophytichum , C. queenslandicum , and C. gloeosporioides. Those three species are C. gloeosporioides species complex, and this is the first report of C. endophytichum , C. queenslandicum causing citrus anthracnose in Indonesia which needs further concern for biosecurity. All isolate sequences based on actin, β-tubulin, and GAPDH gene markers were submitted into the GenBank and got accession numbers of OR188855–OR188875. [ABSTRACT FROM AUTHOR]

Camellia oleifera C. Abel is a woody oil crop with multiple purposes. This study aims to investigate the mutagenic effects of 60Co-γ radiation on C. oleifera seedlings and to screen anthracnose-resistant mutants. Two C. oleifera varieties were investigated: 'Xianglin 1' (XL1) and 'Xianglin 210' (XL210). Seeds were irradiated with 0 Gy, 30 Gy, 50 Gy, and 80 Gy of 60Co-γ, and after one year of planting, the mutagenic lines were studied, and disease-resistant mutants were screened. Results showed that as the radiation intensity was increased, the emergence percentage of both C. oleifera XL210 and XL1 was significantly decreased. Radiation significantly changed the SOD and POD activities in both varieties. Furthermore, 80 Gy irradiated lines showed reduced anthracnose resistance in both varieties. However, 50 Gy irradiated lines showed enhanced disease resistance in XL210 while reducing it in XL1. The 30 Gy irradiated lines did not affect the disease resistance of either variety. Colletotrichum gloeosporioides infection tests were conducted on 94 mutant C. oleifera seedlings, resulting in 8 highly resistant mutants (A3, A8, A10, A19, A21, A32, A35, B17) and 3 susceptible mutants (A4, B15, B27) in XL210 and XL1. Differences in SOD and POD activities led to variations in disease resistance among different mutants. Additionally, the expression levels of CoSOD1, CoPOD, CoIDD4, and CoWKRY78 were varied among the different mutants. This study delivers the screening of disease-resistant mutants in C. oleifera through mutagenic breeding, providing material for the development of new C. oleifera varieties and serving as a resource for further research in mutagenic breeding. [ABSTRACT FROM AUTHOR]

Colletotrichum spp. is a phytopathogen causing anthracnose in a variety of tropical fruits. Strategies used to control postharvest diseases in tropical fruits typically rely on the use of synthetic fungicides, which have stimulated the emergence of resistant pathogens. Safer alternative strategies to control anthracnose in tropical fruits have been described in the literature. This review presents and discusses the main innovative interventions concerning the application of sustainable alternative strategies in the postharvest control of pathogenic Colletotrichum species in tropical fruits, with a particular emphasis on the studies published in the last 5 years. The available studies have shown the use of various methods, including physical barriers, natural antimicrobials, and biological control with antagonistic microorganisms, to reduce anthracnose lesion severity and incidence in tropical fruits. The available literature showed high inhibitory activity in vitro, reduced anthracnose incidence and lesion diameter, and total disease inhibition in tropical fruits. Most studies focused on the inhibition of Colletotrichum gloeosporioides on avocado, papaya, and mango, as well as of Colletotrichum musae on banana; however, the inhibition of other Colletotrichum species was also demonstrated. The application of emerging sustainable alternative methods, including natural antimicrobial substances, also stimulated the induction of defense systems in tropical fruits, including enzymatic activity, such as polyphenol oxidase, peroxidase, and phenylalanine ammonia‐lyase. The retrieved data helped to understand the current state of the research field and reveal new perspectives on developing efficient and sustainable intervention strategies to control pathogenic Colletotrichum species and anthracnose development in tropical fruits. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by Colletotrichum gloeosporioides in mango production, can lead to crop losses of 60 %. Synthetic fungicides constitute its leading management strategy. We evaluated combinations of different management practices to control anthracnose in a commercial Tommy Atkins mango grove in 2015 and 2016. We followed a randomized complete block experimental design with a subdivided plot arrangement composed of 12 treatments, three replicates per treatment, and one mango tree per replicate for 36 trees. Pruning was practiced at plot level (with and without pruning), nutrients were applied to subplots (soil fertilizer, foliar nutrient application, and no nutrient supply), and at sub-subplot level, three anthracnose management treatments were given (chemical, biological, and no treatment). In 2015 and 2016, the treatments involving natural or biological applications against anthracnose plus nutrient supply led to the most significant reductions in quiescent leaf infections and disease presence in flowers and fruits. In addition, pruning at specific crop development stages improved results. In light of our results, this integrated anthracnose management approach in mango production can deliver the expected results if implemented consistently.

Abstract Background DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L). Results In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection. Conclusions Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs.

Anthracnose, caused by Colletotrichum spp., is a threat to strawberry production globally. Unlike their chemical counterparts, microbial biofungicides offer a method of postharvest fungal disease control that is safe, sustainable and less affected by pathogen resistance. The present study evaluated the antifungal effects of three bacteria, Bacillus velezensis strains SH1 and SH2 and Pseudomonas azotoformans strain SH3, obtained from sheep manure compost tea. The bacteria or their cell‐free filtrates were tested against Colletotrichum acutatum and Colletotrichum gloeosporioides in bioassays and against strawberry anthracnose. In addition, precipitated or extracted extracellular fractions were tested to determine the effects on membrane permeability of Colletotrichum spp. spores. Confrontation assay results showed all bacteria inhibited mycelial growth, with B. velezensis SH1 and P. azotoformans SH3 being the most effective. All cell‐free filtrates inhibited mycelial growth with B. velezensis SH1 and SH2 resulting in the highest inhibition. The bacteria suppressed anthracnose lesions on strawberry fruit although effective treatments varied by causal mould. B. velezensis SH1 and SH2 significantly permeabilized spore membranes, indicating antibiosis as a possible mode of action. Investigation into antimicrobial compound production found various homologues of the lipopeptides fengycin, iturin and surfactin were produced by B. velezensis SH1 and SH2. Results suggest that lipopeptides produced by B. velezensis strains permeabilize Colletotrichum cell membranes, and that fengycins were the most inhibitory of the lipopeptides against Colletotrichum spp. [ABSTRACT FROM AUTHOR]

A new extraction and bacteriostatic ability of glucoside alkaloids in potato peel. To make better use of glucoside alkaloids, this experiment adopted ultrasonic microwave combined extraction of glucoside alkaloids from potato peel; then, the extracts of potato peel were subjected to bacteriostatic assays. The optimum experimental condition of response surface method was that the solid-liquid ratio was 1:18.00 g/mL, the ultrasonic power 505.00 W, the microwave time was 6.10 min and the ultrasonic time was 10.70 min. Under those conditions, the extraction amount of glucoside alkaloids was 292.91 mg/kg, which increased by about 28% compared with the QUEChERS method. The antibacterial activity of the obtained glucoside alkaloids was tested using five kinds of strains, and the results showed that Penicillium and Colletotrichum gloeosporioides were more sensitive. The results indicated that Ultrasonic-Microwave combined extraction was more efficient and convenient than that of QuEChERS method for glucoside alkaloids and related antibacterial compounds from potato peel. [ABSTRACT FROM AUTHOR]

Crop disease often leads to field epidemics with serious threats to yield. Early symptoms are sometimes difficult to identify, so the origin of primary inoculum is a critical focal point in the study of plant diseases, as it can help design management strategies to reduce crop losses. Here, we investigated whether anthracnose of water yams (Dioscorea alata L.) caused by the species complex Colletotrichum gloeosporioides can start from infected seed tubers from the previous harvest. Over two years, we collected tubers with varying pathogen prevalence in the field directly from producers and conducted fungal isolations in the lab to sample C. gloeosporioides. We also proceeded to artificially inoculate tubers before planting and monitored disease development. Finally, we genotyped isolates from leaves in the fields and assessed fixation indices between plots based on plot ownership (plots with a common seed tuber origin from a single farmer) vs. samples in plots from unrelated producers in Guadeloupe, Martinique, and Barbados. We were unable to isolate the fungus from harvested tubers in either sampling survey nor did any plants grown from inoculated tubers develop any disease symptoms during growth. Also, the genetic structure of samples within each plot was independent of plot ownership, though this occurred with varying levels in the different islands. These results suggest that contaminated planting material from seed tubers is not the primary source of the disease, which is in contrast to the common perception of yam anthracnose prevalence in the Antilles.

Abstract Background Walnut anthracnose caused by Colletotrichum gloeosporioides seriously endangers the yield and quality of walnut, and has now become a catastrophic disease in the walnut industry. Therefore, understanding both pathogen invasion mechanisms and host response processes is crucial to defense against C. gloeosporioides infection. Results Here, we investigated the mechanisms of interaction between walnut fruits (anthracnose-resistant F26 fruit bracts and anthracnose-susceptible F423 fruit bracts) and C. gloeosporioides at three infection time points (24hpi, 48hpi, and 72hpi) using a high-resolution time series dual transcriptomic analysis, characterizing the arms race between walnut and C. gloeosporioides. A total of 20,780 and 6670 differentially expressed genes (DEGs) were identified in walnut and C. gloeosporioides against 24hpi, respectively. Generous DEGs in walnut exhibited opposite expression patterns between F26 and F423, which indicated that different resistant materials exhibited different transcriptional responses to C. gloeosporioides during the infection process. KEGG functional enrichment analysis indicated that F26 displayed a broader response to C. gloeosporioides than F423. Meanwhile, the functional analysis of the C. gloeosporioides transcriptome was conducted and found that PHI, SignalP, CAZy, TCDB genes, the Fungal Zn (2)-Cys (6) binuclear cluster domain (PF00172.19) and the Cytochrome P450 (PF00067.23) were largely prominent in F26 fruit. These results suggested that C. gloeosporioides secreted some type of effector proteins in walnut fruit and appeared a different behavior based on the developmental stage of the walnut. Conclusions Our present results shed light on the arms race process by which C. gloeosporioides attacked host and walnut against pathogen infection, laying the foundation for the green prevention of walnut anthracnose.

Endophytic fungi can be used as a source of herbal antioxidants to overcome the limitations of low yield and lengthy growth cycles associated with using plants as raw materials for antioxidant production. Papaya fruit is often susceptible to infection by Colletotrichum gloeosporioides after harvest, leading to postharvest rot. Endophytic fungi were extracted with ethyl acetate, and the initial screening concentration was 100 mg/L. Seven strains were identified, with scavenging rates exceeding 50% and strong antioxidant activity. The IC50 values in DPPH and ABTS free radical scavenging assays ranged from 19.72 to 84.06 mg/L and from 14.34 to 64.63 mg/L, respectively. Strain Y17 exhibited robust antioxidant activity (IC50 < 20 mg/L) and was identified as Penicillium rolfsii (MT729953) through ITS sequencing. Treatment of papaya fruit wounds with a fermentation broth of strain Y17 significantly inhibited the infection and colonization of anthracnose pathogens, resulting in a slowed disease incidence rate. This promoted the activity of protective enzymes, such as CAT, POD, and SOD, in the papaya fruit and slowed down the rate of MDA accumulation. This strain, which was found to have antioxidant activity in this study, has the potential to control anthracnose in papaya and has value in terms of further development and utilization. [ABSTRACT FROM AUTHOR]

Here, we report for the first time on the mechanisms of action of the essential oil of Ruta graveolens (REO) against the plant pathogen Colletotrichum gloeosporioides. In particular, the presence of REO drastically affected the morphology of hyphae by inducing changes in the cytoplasmic membrane, such as depolarization and changes in the fatty acid profile where straight-chain fatty acids (SCFAs) increased by up to 92.1%. In addition, REO induced changes in fungal metabolism and triggered apoptosis-like responses to cell death, such as DNA fragmentation and the accumulation of reactive oxygen species (ROS). The production of essential enzymes involved in fungal metabolism, such as acid phosphatase, β-galactosidase, β-glucosidase, and N-acetyl-β-glucosaminidase, was significantly reduced in the presence of REO. In addition, C. gloeosporioides activated naphthol-As-BI phosphohydrolase as a mechanism of response to REO stress. The data obtained here have shown that the essential oil of Ruta graveolens has a strong antifungal effect on C. gloeosporioides. Therefore, it has the potential to be used as a surface disinfectant and as a viable replacement for fungicides commonly used to treat anthracnose in the postharvest testing phase. [ABSTRACT FROM AUTHOR]

Tea (Camellia sinensis (L.) Kuntze) is a dicotyledonous woody shrub species widely cultivated to produce a beverage made from its leaves. Brown blight is a destructive foliar fungal disease that reduces tea production and degrades quality, resulting in lower market value. Typical brown blight symptoms observed in three commercial tea plantations in Malaysia were characterized as brownish to black lesions on young leaves. The lesions expanded with age, becoming darker and developing into necrotic cells. A total of 45 fungal isolates were isolated from brown blighted tea leaves and identified as Colletotrichum camelliae. Morphological characteristics coupled with universal spacer region and multigene phylogenetic relationships using the internal transcribed spacer (ITS), β-tubulin (tub2) and glyceraldehyde-3-phosphate dehydrogenase (gapdh) were used to accurately identify fungal isolates. The results of the pathogenicity test revealed that C. camelliae was responsible for causing brown blight disease of tea. This study highlights the occurrence of C. camelliae which causes tea brown blight in Malaysia. These findings may assist in disease monitoring, strict quarantine and effective control management of diseased tea plants. [ABSTRACT FROM AUTHOR]

Lychee pepper spot, a field disease affecting lychee fruit skin, pedicels and petioles, is caused by Colletotrichum siamense, a fungal pathogen within the gloeosporioides species complex. Members of Colletotrichum from the gloeosporioides species complex and occasionally those from the acutatum species complex also cause postharvest anthracnose of lychee. Pepper spot was first described in Australia many years after anthracnose on lychee was first described, giving rise to the hypothesis that a novel species or strain within the gloeosporioides species complex causes pepper spot. In the present study, 19 isolates of Colletotrichum spp., collected from pepper spot and anthracnose symptoms on lychee fruit, representing 13 different genotypes across five species, were inoculated onto lychee fruit in the field or on detached fruit in the laboratory, to understand more about their pathogenic diversity. We found that symptoms were specific to genotype of the pathogen, as three genetically similar isolates of C. siamense consistently caused pepper spot and anthracnose, whilst other isolates caused anthracnose only. Cross‐inoculation studies on detached fruit of lychee, banana, avocado and mango also provided some evidence of host specialization in isolates of C. siamense infecting lychee in Australia. Our experiments provided further evidence that detached fruit assays cannot be used as a reliable proxy for field inoculation studies. This research confirms that C. siamense is a causal agent of both lychee pepper spot and lychee anthracnose in Australia, and Colletotrichum alienum and Colletotrichum queenslandicum are reported as causal agents of anthracnose of lychee for the first time. [ABSTRACT FROM AUTHOR]

Chili peppers were treated with gamma irradiation to develop anthracnose disease resistance. Seeds of chili peppers were irradiated with gamma rays at 0, 100, 200, 300, 400 and 500 Gy to determine the optimal dose for mutation breeding. The LD50 value was calculated to be 264.83 Gy. The 300 Gy gammairradiated chili pepper seeds (Capsicum annuum L.) were planted in the experiment field at Nan Agricultural Research and Development Center, Thailand for mutation selection. The results showed that the irradiated chili plants not only survived the anthracnose infection but also produced fruits. These fruits were less affected or unaffected by the anthracnose disease compared to the control group (unirradiated) which showed damages on every part of chili plant. The 28 healthy chili pepper plants in M3 generation that showed anthracnose resistant traits were selected as seeds for M4 generation. Two chili pepper lines in M4 generation exhibited the highest resistance to anthracnose. From the pathogenicity test, those 2 chili pepper lines were found to have resistance to anthracnose disease caused by both Colletotrichum gloeosporioides and Colletotrichum capsici. [ABSTRACT FROM AUTHOR]

This study aimed to explore the effects of Bacillus amyloliquefaciens GSBa-1 treatment on anthracnose disease resistance and the metabolism of reactive oxygen species (ROS) and phenylpropanoids in mangoes during storage. Mangoes were soaked in a solution containing 1 × 108 CFU/mL of B. amyloliquefaciens GSBa-1. The anthracnose disease incidence, disease index, respiration intensity, ethylene release, reactive oxygen species content, and the activities of related metabolic enzymes, phenylpropanoid-related metabolic enzymes, and phenolic acids in the skin and pulp of mangoes were investigated under normal temperature storage conditions. The results showed that the antagonistic bacterial treatment (ABT) did not significantly inhibit the growth of Colletotrichum gloeosporioides in vitro. However, it significantly reduced the incidence of mango anthracnose disease when applied to the mango peel. ABT enhanced the latent resistance of mango to anthracnose disease by activating its reactive oxygen and phenylpropanoid metabolism. It maintained higher levels of ROS production and elimination in the peel. Moreover, it rapidly activated manganese superoxide dismutase, induced the accumulation of H2O2, and enhanced the activity of manganese superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase in the mango peel. Furthermore, ABT activated phenylalanine ammonia-lyase, cinnamic acid-4-hydroxylase, 4-coumaroyl-CoA ligase, and cinnamyl alcohol dehydrogenase in the mango peel and pulp, promoting the accumulation of antifungal phenolic acids such as gallic acid, catechins, and ellagic acid. Bacillus amyloliquefaciens GSBa-1 may be a potent inhibitor of mango anthracnose, primarily enhancing the resistance of mangoes to anthracnose by synergistically activating ROS in the peel and phenylpropanoid metabolism in the pulp, thereby reducing the incidence of anthracnose effectively. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides is the main pathogen that causes poplar anthracnose. This hemibiotrophic fungus, which can severely decrease the economic benefits and ecological functions of poplar trees, infects the host by forming an appressorium. Hox7 is an important regulatory factor that functions downstream of the Pmk1 MAPK signaling pathway. In this study, we investigated the effect of deleting CgHox7 on C. gloeosporioides. The conidia of the ΔCgHox7 deletion mutant germinated on a GelBond membrane to form non-melanized hyphal structures, but were unable to form appressoria. The deletion of CgHox7 weakened the ability of hyphae to penetrate a cellophane membrane and resulted in decreased virulence on poplar leaves. Furthermore, deleting CgHox7 affected the oxidative stress response. In the initial stage of appressorium formation, the accumulation of reactive oxygen species differed between the ΔCgHox7 deletion mutant and the wild-type control. Moreover, CgHox7 expression was necessary for maintaining cell wall integrity. Considered together, these results indicate that CgHox7 is a transcription factor with crucial regulatory effects on appressorium formation and the pathogenicity of C. gloeosporioides. [ABSTRACT FROM AUTHOR]

Fungi, including filamentous fungi and yeasts, are major contributors to global food losses and waste due to their ability to colonize a very large diversity of food raw materials and processed foods throughout the food chain. In addition, numerous fungal species are mycotoxin producers and can also be responsible for opportunistic infections. In recent years, MALDI-TOF MS has emerged as a valuable, rapid and reliable asset for fungal identification in order to ensure food safety and quality. In this context, this study aimed at expanding the VITEK® MS database with food-relevant fungal species and evaluate its performance, with a specific emphasis on species differentiation within species complexes. To this end, a total of 380 yeast and mold strains belonging to 51 genera and 133 species were added into the spectral database including species from five species complexes corresponding to Colletotrichum acutatum, Colletotrichum gloeosporioides, Fusarium dimerum, Mucor circinelloides complexes and Aspergillus series nigri. Database performances were evaluated by cross-validation and external validation using 78 fungal isolates with 96.55% and 90.48% correct identification, respectively. This study also showed the capacity of MALDI-TOF MS to differentiate closely related species within species complexes and further demonstrated the potential of this technique for the routine identification of fungi in an industrial context. [ABSTRACT FROM AUTHOR]

Fungal diseases of plants are one of the key factors causing global crop losses. In this study, we isolated a Bacillus velezensis strain VC3, which was found to have a broad-spectrum inhibitory effect on a variety of phytopathogenic fungi through in vitro and in planta experiments, especially on Magnaporthe oryzae and Colletotrichum gloeosporioides. Further genomic and transcriptomic analyses revealed that the B. velezensis VC3 has multiple functional gene clusters encoding for the synthesis of a variety of antifungal secondary metabolites, including antimicrobial peptides (AMPs) and lipopeptides (LPs). In addition, AMPs and LPs were isolated and purified from B. velezensis VC3 fermentation broth and their antifungal activities were verified in this study. AMPs and LPs significantly inhibited spore germination, appressorium formation, and disease development, and AMPs have a better potential for controlling M. oryzae and C. gloeosporioides than LPs. These findings open new avenues for utilizing B. velezensis VC3 as biocontrol agents, providing potential sustainable solutions for agricultural production. [ABSTRACT FROM AUTHOR]

BACKGROUND: Anthracnose caused by species of Colletotrichum is the most important disease of avocado fruit. The quiescent infection develops in the field, hence, its control from the preharvest stage is necessary. The field application of microencapsulated Yamadazyma mexicana LPa14 could prevent the establishment of Colletotrichum gloeosporioides and reduce the losses in avocado production. This study aimed to evaluate the effectiveness of microencapsulated Y. mexicana applied in the field and postharvest for the anthracnose control in avocado, to evaluate the population dynamics of Y. mexicana in flowers and fruits and the effect of the yeast on the avocado quality. RESULTS: The concentrations of microencapsulated Y. mexicana after field application ranged from 4.58 to 6.35 log CFU g−1. The population of microencapsulated yeast in flowers and fruits was always higher than treatments with fresh cells. Preharvest application of fresh and microencapsulated Y. mexicana significantly reduced the severity of anthracnose by 71–80% and 84–96%, respectively, in avocado fruits stored at 25 °C. Moreover, at 6 °C and ripening at 25 °C, the fresh yeast reduced the severity by 87–90% and the microencapsulated yeast by 91–93%. However, yeast treatments applied in the field + postharvest under cool conditions were more effective in reducing 100% of anthracnose. Treatments did not negatively affect the quality parameters of the avocado fruits. CONCLUSION: Yamadazyma mexicana microencapsulated by electrospraying is a promising bioformulation for the management of anthracnose in avocados at preharvest and postharvest levels. Yamadazyma mexicana offers a new biological control solution for growers in avocado orchards. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Anthracnose in citrus is a severe disease caused by Colletotrichum species. Synthetic fungicides have been used to combat this citrus disease; however, they may have adverse health effects on humans and cause harmful environmental impacts. During a search for environmentally friendly fungicides, we successfully prepared organic copper (copper (II) oleate) nanoparticles by using natural chitosan polymer as a coating agent and stabilizer and by combining an exchange reaction and in situ coating method. Organic copper nanoparticles coated with chitosan polymer (Cu‐oleate@CS NPs) with Cu contents ranged from 5.0 to 6.0 % by weight. The nanoparticles have an average particle size ranging from 50 nm to 60 nm (TEM), covered by a layer of polymer with a thickness of about 10 to 12 nm. The analytical results of zeta potential and dynamic solution size showed that the nanoparticles are uniformly dispersed (90–120 nm by DLS), with high stability (zeta potential=−61.7 mV) and low cytoxicity to Vero healthy cell line. Cu‐oleate@CS NPs significantly inhibited the mycelial growth of C. gloeosporioides in vitro at 500 and 1000 μg/mL. In field trials, the best antifungal efficacy of Cu‐oleate@CS NPs against citrus anthracnose on orange plants was found at a spray concentration of 0.33 % with a disease control efficacy of 54.18 % at 14 days after the second spraying. Our study results demonstrated a novel preparation of Cu‐oleate@CS NPs and suggested that it could be used as a promising nanoformulation to control citrus anthracnose in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Leaves of Schima superba with typical anthracnose symptoms were collected in July 2023 in Zhejiang Province, China. The fungi isolates were conducted from the margins of the lesions, and three isolates CA13, CA18 and CA27, were selected for identification and pathogenicity test. Based on morphological characteristics and phylogenetic analyses of the partial regions of internal transcribed spacer (ITS), actin (ACT), calmodulin (CAL), beta‐tubulin (TUB2), and glyceraldehyde‐3‐phosphate‐dehydrogenase sequences (GAPDH), the fungi were identified as Colletotrichum fructicola. Inoculation of the fungi on healthy S. superba leaves showed symptoms similar to those observed in the field, and the fungi were re‐isolated from the lesions. To the best of our knowledge, this represents the first report of C. fructicola causing anthracnose on S. superba worldwide. [ABSTRACT FROM AUTHOR]

Biocontrol, which uses antagonistic microorganisms to manage plant diseases, holds promise for reducing postharvest losses but faces challenges due to varied pathogen responses. In response, biocontrol mixtures were proposed to enhance the antagonistic effect. This study evaluates the efficacy of chitosan and extracellular glucanase (EG) from Wickerhamomyces anomalus, both individually and combined, against Thielaviopsis paradoxa, Colletotrichum gloeosporioides, and Rhizopus stolonifer. The maximum inhibition of mycelial growth by chitosan for these fungi was 90.25% at 3 mg/mL, 14.2% at 5 mg/mL, and 56.28% at 3 mg/mL, respectively. Additionally, chitosan significantly inhibited spore germination across all fungi. While W. anomalus cells prevented mycelial filament association, EG alone had minimal impact on mycelial development but inhibited spore germination in a concentration-dependent manner. Combining EG with chitosan enhanced spore germination inhibition, notably achieving 98.18%. The biocontrol mixture effectively protected fruit under laboratory-controlled conditions, suggesting a robust biocontrol strategy for postharvest fungal disease management. [ABSTRACT FROM AUTHOR]

Plants trigger a robust immune response by activating massive transcriptome reprogramming through crosstalk between PTI and ETI. However, how PTI and ETI contribute to the quantitative or/and qualitative output of immunity and how they work together when both are being activated were unclear. In this study, we performed a comprehensive overview of pathogen‐triggered transcriptomic reprogramming by analyzing temporal changes in the transcriptome up to 144 h after Colletotrichum gloeosporioides inoculated in Populus. Moreover, we constructed a hierarchical gene regulatory network of PagWRKY18 and its potential target genes to explore the underlying regulatory mechanisms of PagWRKY18 that are not yet clear. Interestingly, we confirmed that PagWRKY18 protein can directly bind the W‐box elements in the promoter of a transmembrane leucine‐rich repeat receptor‐like kinase, PagSOBIR1 gene, to trigger PTI. At the same time, PagWRKY18 functions in disease tolerance by modulation of ROS homeostasis and induction of cell death via directly targeting PagGSTU7 and PagPR4 respectively. Furthermore, PagPR4 can interact with PagWRKY18 to inhibit the expression of PagPR4 genes, forming a negative feedback loop. Taken together, these results suggest that PagWRKY18 may be involved in regulating crosstalk between PTI and ETI to activate a robust immune response and maintain intracellular homeostasis. Summary statement: Our research identifies a novel mechanism by which artificial expression of PagWRKY18 is sufficient to confer resistance to hemibiotrophic fungal pathogen Colletotrichum gloeosporioides, and provides insights into the poplar resistance breeding and generating transgenic resistance poplar lines. [ABSTRACT FROM AUTHOR]

Grapevine (Vitis vinifera) is one of the major economic fruit crops but suffers many diseases, causing damage to the quality of grapes. Strain G166 was isolated from the rhizosphere of grapevine and was found to exhibited broad-spectrum antagonistic activities against fungal pathogens on grapes in vitro, such as Coniella diplodiella, Botrytis cinerea, and Colletotrichum gloeosporioides. Whole-genome sequencing revealed that G166 contained a 6,613,582 bp circular chromosome with 5749 predicted coding DNA sequences and an average GC content of 60.57%. TYGS analysis revealed that G166 belongs to Pseudomonas viciae. Phenotype analysis indicated that P. viciae G166 remarkably reduced the severity of grape white rot disease in the grapevine. After inoculation with C. diplodiella, more H2O2 and MDA accumulated in the leaves and resulted in decreases in the Pn and chlorophyll content. Conversely, G166-treated grapevine displayed less oxidative damage with lower H2O2 levels and MDA contents under the pathogen treatments. Subsequently, G166-treated grapevine could sustain a normal Pn and chlorophyll content. Moreover, the application of P. viciae G166 inhibited the growth of mycelia on detached leaves and berries, while more disease symptoms occurred in non-bacterized leaves and berries. Therefore, P. viciae G166 served as a powerful bioagent against grape white rot disease. Using antiSMASH prediction and genome comparisons, a relationship between non-ribosomal peptide synthase clusters and antifungal activity was found in the genome of P. viciae G166. Taken together, P. viciae G166 shows promising antifungal potential to improve fruit quality and yield in ecological agriculture. [ABSTRACT FROM AUTHOR]

Avocado (Persea americana) crop suffers important economic losses due to fungal diseases. Enterolobium cyclocarpum and Amphipterygium adstringens are saponins-producing species and their crude extracts have shown antimicrobial activity. The aim of this work was to evaluate in vitro antifungal activity of aqueous extracts from E. cyclocarpum (leaves and bark), A. adstringens (branches), and their saponins-rich fractions against Colletotrichum gloeosporioides, an avocado pathogen. The fungus was isolated from avocado fruits from Uruapan Michoacan (Mexico) and its molecular identification was performed by sequencing. Saponins-rich fractions (SRF) were obtained by partitioning infusions with n-butanol followed by precipitation with acetone. Antifungal activity of infusions and SRF was evaluated by the agar diffusion method and the strongest growth inhibition of C. gloeosporioides (33%) was achieved with the SRF of E. cyclocarpum bark. Erythrocyte hemolysis was observed with the three infusions and the sarsasapogenin was putatively identified in the product of Amphipterygium branch aqueous extract (ARA) acid hydrolysis by gas chromatography-flame ionization detector (GC-FID). These results highlight the antifungal potential of saponins from this medicinal plant against avocado pathogenic fungi. [ABSTRACT FROM AUTHOR]

Up to 32 Colletotrichum species have been reported to be associated with pre‐ or postharvest diseases of citrus globally, while in Australia, six species have been reported to cause citrus leaf and fruit disease. Twig or shoot dieback has recently been observed as an emerging disease in citrus orchards in Western Australia. Colletotrichum species were isolated from diseased twigs showing dieback (withertip) or lesions, with or without gummosis, collected from 12 varieties of orange, mandarin and lemon. Colletotrichum gloeosporioides sensu stricto, Colletotrichum karstii and Colletotrichum novae‐zelandiae were identified using a polyphasic approach that included multigene phylogenetic analysis using sequences of internal transcribed spacer and intervening 5.8S nrDNA (ITS), glyceraldehyde‐3‐phosphate dehydrogenase (gapdh), β‐tubulin (tub2), actin (act) and histone (his3) for isolates in the boninense species complex, and Apn2–Mat1–2 intergenic spacer and partial mating type (Mat1–2) (ApMat) and glutamine synthetase (gs) for isolates in the gloeosporioides species complex, as well as morphological characteristics. C. gloeosporioides was the most prevalent species associated with twig dieback in Western Australia, while C. novae‐zelandiae was reported for the first time in Australia. Pathogenicity tests on shoot twigs from lemon and orange trees confirmed C. gloeosporioides, C. karstii and C. novae‐zelandiae as the cause of twig dieback, with C. gloeosporioides being the most aggressive species. Knowledge of the species causing twig dieback and their lifestyle will assist the development of integrated control methods. [ABSTRACT FROM AUTHOR]

Mango fruits' quality, marketability, and shelf life are significantly influenced by postharvest decay. Mango fruit disease development during storage is inhibited by fungicides. The objective of this investigation was to assess the relative effectiveness of two fungicides, azoxystrobin 18.2% + difenoconazole 11.4% SC and hexaconazole 5% SC, in mitigating postharvest deterioration of mango cv. 'Langra' during low temperature storage. Three pathogens were found associated with postharvest decay of mango, i.e. Colletotrichum gloeosporioides, Alternaria alternata , and Penicillium expansum. In comparison to untreated ones, the preharvest application of fungicide treatments provided noticeably better disease control. The foliar application of azoxystrobin 18.2% + difenoconazole 11.4% SC (0.1%) 15 days before the harvesting of fruits significantly improved fruit firmness, soluble solid content, titratable acidity, reduced the disease incidence, percentage disease index, and lesion diameter followed by the application of hexaconazole 5% SC (0.1%) compared to the control. Furthermore, it was found that pre-harvest fungicide spraying of azoxystrobin 18.2% + difenoconazole 11.4% SC (0.1%) was an effective treatment for lowering postharvest deterioration and enhancing the physio-chemical characteristics of mango fruits during low-temperature storage. [ABSTRACT FROM AUTHOR]

Chitosan, a modified product of chitin has found application in various fields such as in foods, cosmetics, agricultural products, and pharmaceuticals. This study aim to evaluate the stability and the antifungal activity of chitosan films produced from shrimp shells. Chitosan films with various degrees of deacetylation (70%, 80%, and 90%) were produced from shrimp shells by solution casting and solvent evaporation method. The stability of the chitosan films was evaluated under a controlled environmental conditions over a 35 days period. The key stability parameters monitored include; tensile strenght, elongation at break, elastic modulus, and water vapour permeability. The antifungal activity of the films was investigated against Colletotrichum gloeosporioides using the disc diffusion method. After 35 days, the mechanical properties (tensile strenght, elongation at break, and elastic modulus), and water vapour permeability of the chitosan films remained largely unchanged, indicating sustained stability over time. The chitosan films at the three deacetylation levels (70%, 80%, and 90%) exhibited antifungal activity against Colletotrichum gloeosporioides, with chitosan film with 90% degree of deacetylation showing the highest antifungal activity. From the results of the study, chitosan films at three degrees of deacetylation (70%, 80%, and 90%) have good stability under the storage conditions tested. They are highly active against Colletotrichum gloeosporioides, thus could be used as protective films for food preservation. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides is one of the more economically important pathogen causing anthracnose on crops and trees worldwide. As an essential mineral nutrient, potassium play a vital role for fundamental cellular processes in organisms. In this study, a high-affinity potassium transporter CgTrk1 was identified in C. gloeosporioides. Cytological examinations revealed that CgTrk1 was localized in the plasma membrane. The gene deletion mutant of CgTRK1 significantly depressed the potassium uptake. CgTrk1 is also required for vegetative growth, appressorium development, invasive growth, and full virulence. The data also indicate that CgTrk1 plays dominant roles in potassium uptake and pathogenicity rather than its homologous protein CgTrk2. These results imply that the potassium transporter CgTrk1 is involved in invasive growth and full virulence in C. gloeosporioides. [ABSTRACT FROM AUTHOR]

In this paper, the flocculation and dye recovery potential of a cationic dye, C.I. Basic Blue 41 (BB41), were explored using a natural, fungus-derived flocculant. The influence of various factors on the flocculation, characterization before and after flocculation, as well as adsorption kinetics were investigated. It was observed that an initial pH of 4, without any pH adjustment, favored flocculation, resulting in over 80% decolorization efficiency, whereas a pH of 2 was found to be unfavorable. Because of this acidic-pH responsive property, dyestuffs can be regenerated at pH 2 with a dye recovery efficiency exceeding 60%. The concentration increased by over 3 times when the regeneration occurred in one-tenth of its original volume. Scanning electron microscope (SEM) morphological analysis observed that the dye particles accumulated on the surface of the flocculant. The adsorption process fitted a pseudo-second-order kinetics model. Fourier transform infrared (FTIR) analysis suggested that amide, amine, and hydroxyl groups played important roles in flocculation. These findings were further confirmed with two other textile cationic dyes, C.I. Basic Red 29 (BR29) and C.I. Basic Blue 54 (BB54), both of which exhibited excellent flocculation performance, achieving nearly 100% decolorization efficiency and approximately 40% recovery efficiency. These results suggest that the flocculant used in this study has the potential not only to remediate dyestuffs from textile wastewater but also to recover dyestuffs in a simple manner. [ABSTRACT FROM AUTHOR]