Search Results (247)

Alfalfa anthracnose is an economically significant disease that leads to substantial biomass losses due to stem rot, reduced stand longevity, and a decline in forage nutritional quality. The disease is caused by multiple species within the genus Colletotrichum, including the 14 described species: C. gloeosporioides, C. truncatum, C. lindemuthianum, C. destructivum, C. dematium, C. trifolii, C. medicaginis, C. graminicola, C. coccodes, C. sojae, C. spinaciae, C. lini, C. americae-borealis, and C. tofieldiae. A thorough understanding of key aspects of the pathogen’s biology, along with its epidemiology, infection cycle, and accurate disease diagnosis, is essential for the development of sustainable management strategies. Knowledge of these factors allows us to anticipate disease outbreaks, implement timely interventions, and design integrated control measures that reduce reliance on chemical fungicides while maintaining crop productivity and forage quality. Although anthracnose management has traditionally relied on synthetic fungicides, this review synthesizes alternative control strategies to clarify the current state of knowledge and to provide new insights into the development of effective and sustainable approaches for managing Colletotrichum species. Full article

In the last decade, avocado production has increased in Italy due to the fruit’s high nutritional quality and economic value. During 2024, stem lesions, wood discoloration and dieback, often starting at the grafting point, were observed in young plants in a nursery in Sicily (Italy). Colletotrichum-like colonies were frequently isolated from symptomatic tissues. Multi-locus phylogenetic analysis (gapdh, chs-1, act, tub2, cal, gs and ApMat) was conducted on 11 representative isolates, identifying 6 as C. perseae and 5 as C. gloeosporioides sensu stricto (s.s.). Two representative isolates were selected for pathogenicity tests performed on 2-year-old avocado plants cultivated in a greenhouse. After two months, necrotic lesions, wood discoloration and reddish-brown streaking at the inoculation point were induced in both species. Additional inoculations of avocado fruit confirmed the ability of both species to cause fruit rot. All inoculated fungi were successfully re-isolated and identified, fulfilling Koch’s postulates. This is the first report of stem lesions and dieback caused by Colletotrichum species and the first occurrence of C. perseae in avocado plants in Europe. The results highlight the importance of early monitoring in nurseries during the propagation process and contribute to a better understanding of fungal diseases in avocado crops in Italy. Full article

Latex-producing plants harbor unique microbial communities that may play important roles in host defense; however, their diversity and biocontrol potential remain largely unexplored. Characterizing these communities provides opportunities to identify novel microbial-derived antifungal agents for sustainable crop protection. Bacterial strains were isolated from the latex of Alstonia scholaris (L.) R. Br. and identified using 16S rRNA gene sequencing. Antifungal activity was evaluated against four phytopathogens: Fusarium graminearum, Colletotrichum musae, Colletotrichum gloeosporioides, and Glomerella cingulata. Bioassay-guided fractionation, size-exclusion chromatography, SDS-PAGE, and LC-MS/MS were used to characterize antifungal proteins. Nine bacterial strains were isolated, including eight Bacillus spp. and one Enterococcus faecalis. Among them, Bacillus sp. AsL-2 exhibited the strongest broad-spectrum antifungal activity, inhibiting fungal growth by up to 80%. The antifungal activity of its crude extract remained stable over a wide temperature range. Further characterization identified a novel endo-β-1,3-1,4-glucanase enzyme (~23 kDa) as the major antifungal protein. This study reveals A. scholaris latex as an underexplored microbial niche and identifies Bacillus sp. AsL-2, affiliated with the B. velezensis–B. amyloliquefaciens species complex, as a promising biocontrol candidate. The identified antifungal enzyme represents a potential natural alternative to synthetic fungicides for sustainable agricultural disease management. Full article

Bacillus velezensis strain G2T39 is an endophytic bacterium previously isolated from Crotalaria retusa L., with evidenced biocontrol activity against Fusarium oxysporum f. sp. Cubense and Fusarium graminearum. In this study, it was shown that this strain also exhibited biocontrol activity against Colletotrichum gloeosporioides and Fusarium oxysporum f. sp. Vasinfectum, two important crop pathogens in tropical zones. Comprehensive phylogenetic and genomic analyses were performed to further characterize this strain. The genome of B. velezensis G2T39 consists of a single circular chromosome of 4,040,830 base pairs, with an average guanine–cytosine (GC) content of 46.35%. Both whole-genome-based phylogeny and average nucleotide identity (ANI) confirmed its identity as B. velezensis, being closely related to biocontrol and plant growth promotion Gram-positive model strains such as B. velezensis FZB42. Whole-genome annotation revealed 216 carbohydrate-active enzymes and 14 gene clusters responsible for secondary metabolite production, including surfactin, macrolactin, bacillaene, fengycin, bacillibactin, bacilysin, and difficidin. Genes involved in plant defense mechanisms were also identified. Additionally, G2T39 genome harbors multiple plant growth-promoting traits, such as genes associated with nitrogen metabolism (nifU, nifS, nifB, fixB, glnK) and a putative phosphate metabolism system (phyC, pst glpQA, ugpB, ugpC). Additional genes linked to biofilm formation, zinc solubilization, stress tolerance, siderophore production and regulation, nitrate reduction, riboflavin and nicotinamide synthesis, lactate metabolism, and homeostasis of potassium and magnesium were also identified. These findings highlight the genetic basis underlying the biocontrol capacity and plant growth-promoting properties of B. velezensis G2T39 and support its potential application as a sustainable bioinoculant in agriculture. Full article

Fungal pathogens, including Colletotrichum gloeosporioides and Pestalotiopsis spp., are significant threats to global cacao production. Understanding their varying responses to novel antifungal agents is crucial for developing sustainable plant protection strategies. This study investigated the quantitative morphological responses and isolate-specific sensitivity of three cacao pathogen isolates (one Pestalotiopsis sp. and two C. gloeosporioides) to four novel bio-based phenolic-branched fatty acids and their corresponding amides derived from renewable feedstocks. We observed a high degree of isolate-specific susceptibility. A phenol-branched soy oil-derived fatty amide (PhSOAM) proved most potent, significantly inhibiting the growth of Pestalotiopsis sp. and one C. gloeosporioides isolate. In contrast, the second C. gloeosporioides isolate displayed complete insensitivity to all tested compounds, highlighting significant intraspecific variation. Notably, quantitative image analysis revealed that PhSOAM uniquely altered fungal colony morphology by significantly increasing the length-to-width ratio, suggesting a mechanism of action involving the disruption of polarized growth. Multivariate analyses and machine learning models (R² up to 0.74) effectively classified these responses, identifying the specific pathogen-compound pairing as the most critical determinant of the interaction outcome. This work not only highlights the potential of bio-based amides but also establishes a powerful analytical framework, combining morphological profiling with predictive modeling, to gain deeper insights into the complex, isolate-specific nature of fungal–antifungal interactions. Full article

The genus Streptomyces is the largest group within the phylum Actinobacteria, recognized for producing antibiotics and enzymes, with wide applications in medicine and biological control for crop protection against phytopathogens. In this study, the Streptomyces sp. Caat 5-35 strain, isolated from soil of the Caatinga biome in Brazil, and identified by analysis of the 16S rRNA gene, demonstrated its antagonistic effect in vitro in dual cultures against Phytophthora palmivora, Colletotrichum acutatum, Fusarium oxysporum, Rhizoctonia solani, Sclerotinia sclerotiorum, and Fusarium graminearum. Caat 5-35 inhibited mycelial growth ranging from 19% to 73.3%. Compounds purified by prep-HPLC from extracts were identified by spectral data analysis using UHPLC-triple-TOF-MS/MS, or nuclear magnetic resonance (NMR). This work demonstrated for the first time the anti-oomycete activity of albofungin, its derivatives, and albonoursin against P. palmivora. Moreover, the growth inhibition of Colletotrichum gloeosporioides by albonoursin and the antibacterial effect of 2-chloroadenosine and 5′-O-sulfamoyl-2-chloroadenosine against Pectobacterium carotovorum were demonstrated as novel findings. Caat 5-35 exhibited the ability to solubilize phosphates and produce cellulases on CMC agar. The findings of this study, in combination with in vitro bioassays on cacao pods (Theobroma cacao L.) inoculated with the antagonist strain and P. palmivora APB-35, demonstrate that Streptomyces sp. Caat 5-35 is a source of natural products with applications in agriculture and could serve as an alternative for crop protection. Full article

Biological control using beneficial microbes offers a sustainable alternative to chemical fungicides for managing postharvest diseases. This study reports the isolation and characterization of Bacillus amyloliquefaciens AsL-1 from the latex of Alstonia scholaris (L.) R. Br., unconventional ecological niche. The cell-free supernatant (CFS) of AsL-1 showed strong antifungal activity, inhibiting the growth of Colletotrichum musae (48.89 ± 0.57%), Glomerella cingulata (52.22 ± 0.00%), Fusarium graminearum (47.78 ± 0.57%), and Colletotrichum gloeosporioides (47.78 ± 0.00%) in vitro. Microscopy revealed that the CFS disrupted fungal development by blocking conidial germination and appressorium formation, and in C. gloeosporioides caused melanization defects linked to reduced virulence. In vivo tests on mango fruit confirmed that AsL-1 significantly decreased anthracnose lesion size and disease incidence. Protein analyses (SDS-PAGE, gel overlay, and LC-MS/MS) identified two antifungal proteins (24 and 16 kDa), corresponding to β-1,3-1,4-glucanase and flagellin. The detected β-1,3-1,4-glucanase activity indicates its role in degrading fungal cell walls and interfering with melanin biosynthesis pathways essential for pathogenicity. Overall, these findings highlight B. amyloliquefaciens AsL-1 as a promising protein-based biocontrol agent and show that latex-associated microbes may serve as valuable sources of new antifungal strategies. Full article

Colletotrichum gloeosporioides causes rubber tree anthracnose and leads to serious loss in natural rubber production. Autophagy is a highly conserved process to maintain nutrient recycling and plays important roles in growth, development and pathogenicity in plant pathogenic fungi. The process of autophagy is modulated by a series of autophagy-related (ATG) genes. ATG16 is a subunit of the ATG12-ATG5-ATG16 complex which functions in a manner analogous to an E3-like enzyme which is essential for autophagosome formation. However, the function of the ATG16 homolog in C. gloeosporioides remains unknown. In this study, the ATG16 homolog of C. gloeosporioides was identified and named as CgATG16. The expression level of CgATG16 was particularly higher in conidium, germination, appressorium, and the early stage of infection, and significantly induced by nutritional deficiency. Absence of CgATG16 led to slower colony growth, decreased conidia production and germination rate, longer germ tube cells, lower appressorium formation rate and impaired pathogenicity to rubber tree leaves. Absence of CgATG16 resulted in lower melanin content with decreased expression of polyketide synthase gene CgPKS1 and scytalone dehydratase gene CgSCD1. Moreover, absence of CgATG16 also led to the universal autophagy marker ATG8-GFP failing to enter into the vacuoles in mycelium and during appressorium development with a significantly reduced autophagosome number. Both rapamycin and cyclic adenosine monophosphate (cAMP) partially restored the appressorium formation ability in CgATG16 knockout mutant. Absence of CgATG16 increased the activity of target of rapamycin (TOR) kinase and decreased the content of cAMP. These data suggest that CgATG16 contributes to the pathogenicity of C. gloeosporioides to the rubber tree by regulating the mycelium growth, melanin synthesis and the formation of invasion structure, and this process is related to autophagy mediated by TOR and cAMP signaling. Full article

Anthracnose, caused by the Colletotrichum sp. gloeosporioides complex, severely affects guava quality, highlighting the need for sustainable alternatives to synthetic postharvest fungicides. This study is the first to evaluate modulated UV-C radiation as an innovative approach to controlling postharvest diseases and extending guava shelf-life. The modulation frequency significantly influenced mycelial growth and conidial germination, following a quadratic model (R² = 0.98), with maximum efficacy at ~30 Hz, reducing germination to 5.3 × 10⁴ CFU per plate. In vivo, the combinations of 0.99 kJ m⁻²/30 Hz and 0.66 kJ m⁻²/45 Hz inhibited anthracnose incidence and severity. Most physicochemical parameters remained unaffected after seven days of storage. However, treated fruits showed a higher hue angle (h) and lower a*, indicating the maintenance of shades closer to green due to slower chlorophyll degradation, and firmness was preserved, suggesting delayed ripening. Modulated UV-C also significantly reduced the respiration rate, lowering the climacteric peak. These findings demonstrate that anthracnose control depends on the modulation frequency, with 0.99 kJ m⁻²/30 Hz being particularly effective. Modulated UV-C radiation represents a promising, sustainable, and effective strategy for improving guava postharvest quality and shelf-life. Full article

This study conducted a systematic investigation and identification of pathogenic fungi associated with anthracnose symptoms on economically important plants across multiple provinces in China (Beijing, Fujian, Guangdong, Guizhou, and Shaanxi). Through multi-locus phylogenetic analysis (ITS, gapdh, chs-1, act, tub2, his3, and cal) and morphological characterization of 67 strains, a total of 16 Colletotrichum species were identified, belonging to six species complexes (C. acutatum, C. boninense, C. destructivum, C. gloeosporioides, C. orchidearum, and C. spaethianum). Among these, four novel species were described: Colletotrichum aquilariae, C. crataegi, C. dongguanense, and C. flavosporum. The study also confirmed 12 known species: C. boninense, C. fioriniae, C. fructicola, C. godetiae (with C. americanum proposed as its synonym), C. gloeosporioides (with C. juglandicola, C. juglandium, and C. peakense proposed as its synonyms), C. karsti, C. nymphaeae, C. orchidearum (with C. subplurivorum proposed as its synonym), C. plurivorum, C. siamense, C. sojae, and C. spaethianum. The research revealed significant pathogen species diversity, distinct geographical distribution patterns (greatest diversity in Beijing, novel species primarily from Guangdong), and host preferences (e.g., C. gloeosporioides was the most widely distributed and dominant species on walnut). Furthermore, ten new host records were reported. The study explored correlations between pathogens and their hosts, particularly walnut, providing a crucial foundation for understanding the pathogen composition and ecology of anthracnose diseases affecting plants in China. Full article

Argemone mexicana L. is considered a weed; however, it contains secondary metabolites that can control phytopathogenic fungi in vitro, with the potential to adapt its effectiveness in the field. In the present study, leaf extracts of A. mexicana (hexane and methanol) were prepared, and their chemical profiles were analyzed using gas chromatography–mass spectrometry (GC-MS). The in vitro antifungal activity of each extract was evaluated at different concentrations (500, 1000, 2000, 4000, and 8000 mg L⁻¹) against phytopathogens such as Monilinia fructicola, Colletotrichum gloeosporioides, Fusarium oxysporum, and Sclerotinia sclerotiorum. Based on their chemical profiles, 14 compounds were identified in the hexanic extract, and 11 compounds were identified in the methanolic extract. These compounds included those with antifungal activity, such as Benzene; 1.3-bis(1.1-dimethylethyl)-; pentanoic acid; 5-hydroxy-, 2,4-di-1-butylphenyl esters; 1,2,4-Triazol-4-amine; and N-(2-thienylmethyl). The hexanic extract demonstrated fungistatic activity on the four fungi tested, while the methanolic extract exhibited fungicidal activity against C. gloeosporioides and F. oxysporum. The results of the Probit analysis showed variations in the sensitivity of phytopathogenic fungi to the treatments evaluated. In M. fructicola, the hexane extract presented an EC₅₀ of 317,146 mg L⁻¹ and an EC₉₀ of 400,796 mg L⁻¹. For C. gloeosporioides, the EC₅₀ was 2676 mg L⁻¹ and the EC₉₀ was 888,177 mg L⁻¹, while in F. oxysporum an EC₅₀ of 34,274 mg L⁻¹ and an EC₉₀ of 1528 mg L⁻¹ were estimated. In the case of S. sclerotiorum, an EC₅₀ of 560 mg L⁻¹ and an EC₉₀ of 7776 mg L⁻¹ were obtained. Finally, for the commercial fungicide Captan^®, an EC₅₀ of 1.19 mg L⁻¹ and an EC₉₀ of 1.67 mg L⁻¹. These results suggest that extracts from A. mexicana could provide a natural alternative for the control of phytopathogenic fungi. Full article

Colletotrichum gloeosporioides causes anthracnose on a wide range of plants, resulting in serious economic losses worldwide. However, the molecular mechanisms underlying its pathogenicity still remain largely unknown. In the past 20 years, the importance of acetylation/deacetylation modification in the pathogenicity of phytopathogens has already been highlighted, but how it functions in C. gloeosporioides is obscure. Here, we identified and functionally characterized a histone acetyltransferase CgHat1 in C. gloeosporioides. As suspected, CgHat1 is localized to the nucleus and regulates the acetylation levels of histone H4K5 and H4K12. Targeted gene deletion revealed that CgHat1 plays crucial roles in growth, colony pigmentation, and conidiation. Furthermore, we provided evidence showing that ΔCghat1 mutant is defective in conidial germination, appressorial formation, and response to endoplasmic reticulum (ER) stress. These combined effects lead to the decreased pathogenicity of ΔCghat1 mutant. Our studies not only firstly shed light on the pleiotropic roles of histone acetyltransferase in C. gloeosporioides, but also offer a potential fungicide target for anthracnose control. Full article

This study evaluated the efficacy of essential oils (EOs) for the postharvest management of anthracnose caused by Colletotrichum gloeosporioides in mango. EOs from Cinnamon (Cinnamomum zeylanicum), Oregano (Origanum vulgare), Rosemary (Salvia rosmarinus), and Black pepper (Piper nigrum) were chemically characterized using gas chromatography–mass spectrometry (GC–MS). The main compounds identified included eugenol, methyl eugenol, carvacrol, and eucalyptol, all recognized for their antifungal and antioxidant properties. In vitro assays showed that cinnamon and black pepper EOs significantly inhibited mycelial growth of C. gloeosporioides at all tested concentrations, whereas rosemary EO exhibited lower efficacy. In vivo experiments confirmed that all tested EOs significantly reduced disease severity in mango fruits compared to the control. Overall, the antifungal activity of EOs was dose-dependent and strongly influenced by their chemical complexity and synergistic interactions among major and minor components. These findings highlight the relevance of oxygenated monoterpenes, hydrocarbon monoterpenes, and sesquiterpenes as candidate groups for developing sustainable alternatives for the control of C. gloeosporioides in mango production. Full article

Anthracnose is a leaf fungal disease caused by multiple Colletotrichum species. Currently, the predominant deployment of chemical agents for anthracnose control increases ecological pollution risks and potential food safety concerns. The comprehension of the pathogenic mechanism and physicochemical properties of anthracnose is, therefore, essential for effective prevention and control. In this study, the pathogenic strain (pathogen) was isolated from the infected tea plant (Camellia sinensis) leaves and was identified as Colletotrichum gloeosporioides based on microscope observations and gene sequences. This fungus exhibited optimal growth at 28 °C and a pH of 6, with a lethal temperature threshold of 53 °C on PDA plate medium. The 80% tea saponin and 10% polymycin B could effectively inhibit its mycelium growth. Notably, the 10% polyoxin B exhibits a stronger inhibitory effect with an EC₅₀ value of 1.07 mg mL⁻¹. Following infection with Colletotrichum gloeosporioides, the resistant cultivar ‘Zhongcha 108’ exhibited higher levels of H₂O₂ and O₂⁻ than the susceptible ‘Longjing 43’, with later symptom onset and slower disease progression. Although the exogenous treatment of methyl jasmonate (MeJA) did not inhibit C. gloeosporioides directly, it significantly reduced lesion areas in ‘Longjing 43’ leaves caused by C. gloeosporioides. This treatment increased peroxidase and superoxide dismutase activities, but limited malondialdehyde content, thereby enhancing ‘Longjing 43’ resistance to the pathogen. The findings provide scientific guidance for the anthracnose prevention and control in tea gardens. Full article

Anthracnose is one of the most serious postharvest diseases that can manifest in mango. The mechanism and inhibitory effects of β-aminobutyric acid (BABA) on anthracnose in harvested mango fruit were investigated. The “Guifei” fruits were pretreated with different concentrations of 25, 50, 75, and 100 mmol/L BABA, with 0 mmol/L BABA as the control, and inoculated with Colletotrichum gloeosporioides. The results showed that 50 mmol/L BABA treatment significantly reduced the incidence of anthracnose and inhibited the growth of lesions in mango. It significantly increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), while reducing the O₂⁻ production rate and H₂O₂ content. In addition, the DPPH radical scavenging capacity was enhanced, the content of disease-resistance-related compounds, including total phenols and total flavonoids, increased, and the expression levels of defense-related genes such as PAL, GLU, CHI, and PR1 were upregulated, elevating the activity of phenylalanine ammonia-lyase (PAL) and pathogenesis-related proteins such as chitinase (CHI) and β-1,3-glucanase (GLU). In conclusion, BABA treatment significantly enhances mango fruit resistance to anthracnose via synergistically activating the antioxidant defense system, promoting the accumulation of disease-resistant compounds, and regulating defense-related gene expression. These findings provide a theoretical foundation for developing eco-friendly strategies to control postharvest diseases in mango. Full article