Search Results (113)

Colletotrichum capsici is an important pathogen causing anthracnose in postharvest peppers in parts of Asia, seriously compromising quality and storage life. Unveiling the pathogenic mechanism can better prevent postharvest disease in pepper. This study investigated the impacts of C. capsici infection on cell wall and phenylpropanoid metabolism in postharvest pepper. Compared to the non-inoculated peppers, C. capsici infection notably increased the disease index, damaged visual quality, and reduced the firmness. Morphological observations showed that C. capsici infection contributed to the collapse of epidermal cell structure. During the early stage, C. capsici triggered pepper’s defensive responses, including lignin deposition around the wounds, increased cellulose and hemicellulose content, and boosted disease-resistance enzymes, including phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), laccase (LAC), β-1,3-glucanase (β-1,3-Glu), and chitinase (CHI), alongside elevated total phenolics and flavonoids. However, as storage time progressed, the activities of carboxymethy cellulase (Cx), polygalacturonase (PG), pectin methylesterase (PME), and β-glucosidase (β-Glu) remained at a high level, leading to a reduction in cell wall components, a decline in the activities of disease-resistance enzymes, and a decrease in phenylpropanoid metabolite, resulting from disease progression in pepper. These insights highlight the need for early intervention strategies to mitigate postharvest losses by targeting pathogen-induced stress responses and cell wall integrity preservation. Full article

Pepper anthracnose is a globally devastating fungal disease caused by Colletotrichum spp. In this study, we explored the molecular mechanisms underlying anthracnose resistance in Capsicum annuum by comparing a resistant variety 225 with a susceptible variety 307. Phenotypic analysis revealed that variety 225 displayed stronger resistance than variety 307. Through comparative transcriptome analysis and weighted gene co-expression network analysis (WGCNA), 17 gene modules were identified, among which the salmon module showed a strong association with resistance in variety 225. Within this module, 18 hub genes—including Ca59V2g00372.1 (CaTLP6), encoding a thaumatin-like protein (TLP)—were significantly upregulated upon infection. A genome-wide analysis identified 31 CaTLP genes in C. annuum, with members of group V (such as CaTLP6) exhibiting induced expression post-inoculation of Colletotrichum scovillei. Subcellular localization analysis indicated that group V CaTLP proteins were associated with the plasma membrane, suggesting a role in pathogen recognition. These findings highlight the significance of CaTLP genes, particularly those in group V, in pepper’s defense against anthracnose caused by C. scovillei and offer promising targets for breeding resistant cultivars. Full article

Streptomyces vinaceus strain SVFJ-07 is a biocontrol bacterium employed to control anthracnose disease caused by Colletotrichum gloeosporioides in Chinese orchids. This study investigated the mechanism of strain SVFJ-07-induced stomatal immunity-related closure in preventing the infection of anthracnose disease. After the foliar application of strain SVFJ-07, we analyzed the differential patterns of stomatal opening in Chinese orchids and measured the hormone levels of abscisic acid (ABA) and salicylic acid (SA). RNA sequencing (RNA-seq) was utilized to examine the differential expression of genes involved in SA and ABA signal transduction and disease resistance genes, which were induced by strain SVFJ-07. The results demonstrated that strain SVFJ-07 inhibited the infection of pathogens by inducing stomatal closure. Compared with the control group, the foliar application of strain SVFJ-07 significantly reduced stomatal length, width, and aperture. Furthermore, orchid plants treated with strain SVFJ-07 and infected with C. gloeosporioides exhibited elevated levels of endogenous ABA and SA, indicating that strain SVFJ-07 enhanced stomatal immunity and disease resistance in these plants. The transcriptome analysis revealed the upregulation of genes associated with stomatal immunity, particularly those involved in plant–pathogen interactions, peroxisome metabolism, plant hormone signaling, and mitogen-activated protein kinase (MAPK) signaling pathways. These findings confirmed that the induction of SVFJ-07 promoted stomatal closure to resist the infection of C. gloeosporioides and induced complex transcriptome-wide changes. Further investigation of the differentially expressed genes enhanced our understanding of the resistance mechanisms induced by S. vinaceus strain SVFJ-07. Full article

Soybean is one of the main agricultural commodities, and its productivity is limited by several diseases, such as anthracnose, which is caused by a complex of fungal species, with Colletotrichum truncatum being the most prevalent. Management is mainly carried out through chemical seed treatment. However, a reduction in the sensitivity of C. truncatum to fungicides was observed. Therefore, it is extremely important to search for products that are effective in controlling the disease. The objectives of this study were to evaluate the efficacy of commercial formulations of copper, potassium, manganese, and zinc phosphites in the treatment of soybean seeds infected by C. truncatum, as well as their direct fungitoxicity and ability to induce soybean defense mechanisms. For this purpose, seeds inoculated with C. truncatum were subjected to phosphites and a fungicide (carbendazim + thiram). The seeds were exposed to germination, health, and vigor tests. Fungal toxicity and the ability of phosphites to induce defense through the activities of catalase, peroxidase, and superoxide dismutase enzymes, as well as the levels of lignin and total soluble phenols, were also evaluated. Mn and Zn phosphites showed direct toxicity to C. truncatum and were as effective as the fungicide (carbendazim + thiram) in treating soybean seeds infected by the fungus. Mn phosphite induced the production of catalase (CAT), peroxidase (POX) and lignin, while Zn phosphite increased the production of CAT and POX. These results demonstrate the efficacy of Mn and Zn phosphites in controlling C. truncatum in infected soybean seeds, their direct toxic action, and their ability to induce resistance. Full article

Poplar anthracnose, caused by Colletotrichum gloeosporioides, significantly threatens global poplar cultivation, with rising temperatures further intensifying environmental stress on trees. As autotrophic organisms, plants rely on photosynthesis for growth and stress responses, making this process particularly vulnerable under combined stressors, such as heat and pathogen infection. This study investigates the dual-stress response mechanisms of the resistant poplar species Populus × canadensis through integrated transcriptomic and metabolomic analyses. Results show that C. gloeosporioides inoculation at ambient temperature conditions activates multiple defense-related pathways, including MAPK signaling and ferroptosis. High temperatures amplify these responses, leading to extensive alterations in gene expression, particularly in pathways related to the cell cycle, photosynthesis, and phytohormone signaling. The chlorophyll content, a key marker of photosynthetic efficiency, is significantly reduced under high temperatures, with dual stress causing the most pronounced declines in chlorophyll a and b and total chlorophyll levels. These findings provide valuable insights into the molecular mechanisms underlying poplar resilience to anthracnose and heat stress, offering a foundation for breeding climate-resilient and pathogen-resistant tree cultivars. Full article

Anthracnose is a widespread plant disease affecting vegetables, flowers, crops, and fruit trees, causing significant economic losses. It occurs at various stages of pepper growth, leading to rotting and shedding in later stages. The aim of this study was to explore the relationship with anthracnose occurrence by analyzing the physicochemical properties and microbiota changes in the inter-root soil of pepper under different susceptibility levels to reveal the key microecological factors and dominant microbial populations and to provide reference for ecological control. Illumina Miseq sequencing was first used to evaluate the physicochemical properties and microbial taxa in pepper inter-root soil across different health statuses and identify key parameters associated with anthracnose. Subsequently, PICRUSt2 (systematic genetic Investigation of communities by Reconstruction of observed States 2) and FUNGuild (Fungi Functional Guild) V1.0 online platform were used to predict the activities of inter-root bacteria and fungi. The findings indicated that healthy peppers had significantly higher inter-root soil nutrient levels and enzyme activity compared to sensitive peppers. There were significant differences between their community structures. In alpha-diversity analysis, inter-root soil microbial richness and diversity were significantly higher in healthy peppers than in susceptible peppers. At the bacterial taxonomic level, the comparative prevalence of Acidobacteria in highly resistant plants, resistant plants, and susceptible plants decreased sequentially. At the genus level, the relative abundance of Vicinamibacteraceae and RB41 was markedly elevated in disease-resistant inter-root soils than in disease-susceptible soils. At the fungal level, the comparative prevalence of Ascomycetes in highly resistant plants, resistant plants, and susceptible plants increased sequentially. Differences in function are mainly manifested in apoptosis and mycelial development. Full article

The present study aimed to chemically profile the hydroalcoholic extracts from the microalgae (MEs) Nannochloropsis oculata, Phaeodactylum tricornutum, Tetradesmus obliquus, and Tetraselmis tetrathele and evaluate their effects on the development of Colletotrichum lindemuthianum and anthracnose symptoms, as well as on the initial growth of bean plants. For this, MEs were analyzed using UPLC coupled with a mass spectrometer, allowing the identification of peaks and annotation of potential metabolites. Fungal mycelial growth was assessed seven days after inoculation, and conidial germination was measured 72 h after incubation, using ME concentrations of 0, 0.1, 0.5, and 1.0 mg·mL⁻¹. Bean seeds of the IPR Uirapuru cultivar were sown and treated with 3 mL of extracts at four time points: at sowing and 72 h after each previous treatment. After 11 days of cultivation in a growth chamber, the plants were divided into two groups: one for anthracnose control assessment and the other for evaluating growth promotion by MEs. Plant length as well as fresh and dry weights of shoots and roots were determined, leaf pigments were quantified, and anthracnose severity was assessed using a diagrammatic scale. The UPLC analysis identified 32 compounds in the extracts of the four microalgae, belonging to different chemical and functional groups, with lipids being the most significant fraction. The extracts exhibited variability and diversity in chemical composition depending on the microalgal species. MEs did not affect mycelial growth yet increased the germination of C. lindemuthianum conidia, regardless of the dose or species used. Anthracnose severity was not affected by the microalgae extracts. Regarding growth promotion, the extracts showed varying effects but generally increased shoot and root length, fresh biomass, and leaf pigment content. Full article

Sorghum (Sorghum bicolor L.) is a globally important energy and food crop that is becoming increasingly integral to food security and the environment. However, its production is significantly hampered by various fungal phytopathogens that affect its yield and quality. This review aimed to provide a comprehensive overview of the major fungal phytopathogens affecting sorghum, their impact, current management strategies, and potential future directions. The major diseases covered include anthracnose, grain mold complex, charcoal rot, downy mildew, and rust, with an emphasis on their pathogenesis, symptomatology, and overall economic, social, and environmental impacts. From the initial use of fungicides to the shift to biocontrol, crop rotation, intercropping, and modern tactics of breeding resistant cultivars against mentioned diseases are discussed. In addition, this review explores the future of disease management, with a particular focus on the role of technology, including digital agriculture, predictive modeling, remote sensing, and IoT devices, in early warning, detection, and disease management. It also provide key policy recommendations to support farmers and advance research on disease management, thus emphasizing the need for increased investment in research, strengthening extension services, facilitating access to necessary inputs, and implementing effective regulatory policies. The review concluded that although fungal phytopathogens pose significant challenges, a combined effort of technology, research, innovative disease management, and effective policies can significantly mitigate these issues, enhance the resilience of sorghum production to facilitate global food security issues. Full article

Background: Resistance (R) genes are crucial for defending Perilla against pathogens like anthracnose, downy mildew, and phytophthora blight. Nucleotide-binding site leucine-rich repeat (NBS-LRR) genes, the largest R-gene family, play a central role in immunity. This study aimed to identify and characterize NBS-LRR genes in P. citriodora ‘Jeju17’. Methods: Previously conducted genome-wide data for ‘Jeju17’ were analyzed in silico to identify NBS-LRR genes. Results: A total of 535 NBS-LRR genes were identified, with clusters on chromosomes 2, 4, and 10. A unique RPW8-type R-gene was located on chromosome 7. Conclusions: This study provides insights into the NBS-LRR gene family in ‘Je-ju17’, highlighting its role in disease resistance and evolutionary dynamics. By identifying can-didate R-genes, this research supports breeding programs to develop disease-resistant cultivars and improves our understanding of plant immunity. Full article

Lucky bamboo (Dracaena sanderiana hort. ex. Mast. = Dracaena braunii) is a popular decorative plant in China. In March 2022, a severe outbreak of anthracnose disease occurred on the stems of lucky bamboo plants in a nursery garden in Nanjing, Jiangsu Province, China. Thirty-two fungal isolates were obtained from the infected stem tissues and were morphologically identified as Colletotrichum species. A multilocus phylogenetic analysis based on the internal transcribed spacer (ITS) region, the actin (ACT) gene, and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene indicated the isolate FGZ-1 as Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. The pathogenicity of isolate FGZ-1 was verified by inoculating mycelial plugs on stem segments and spraying spores on the whole one-year-old lucky bamboo plants. Koch’s postulates were fulfilled via the re-isolation of C. gloeosporioides from the diseased tissues. To the best of our knowledge, this is the first report of C. gloeosporioides causing anthracnose on lucky bamboo in China. The detection of C. gloeosporioides on lucky bamboo in China expands the range of Colletotrichum species that are associated with anthracnose in this popular ornamental plant. This study lays a solid foundation for future investigations into the pathogenic mechanisms of anthracnose on D. sanderiana and control strategies for this disease, such as biocontrol agents and the construction of resistant cultivars. Full article

Anthracnose and grain mold are two of the most significant diseases of sorghum, a versatile crop that plays an important part in the daily lives of millions of inhabitants, especially in the drier tropical regions. The aim of this study was to determine the influence of four agronomic traits in selected sorghum germplasms on the two diseases using Spearman’s ρ test to identify significant pairwise correlations. Both anthracnose and grain mold scores were significantly and negatively correlated with seed weight and germination rate. The grain mold infection score also demonstrated negative correlations with plant height (Spearman ρ = −0.61 and p-value = <0.0001) and panicle length (Spearman ρ = −0.27 and p-value = 0.0022). In this investigation, principal component analysis and clustering variables analysis revealed that seed weight and germination rate exhibited a directional alignment, suggesting a positive association. Similarly, panicle length and plant height clustered together, suggesting a shared variation pattern. Additionally, a support vector machine and random forest models effectively predicted the germination rate based on the studied traits, highlighting the potential of machine learning in understanding complex trait relationships in sorghum. This work provides insights into the relationship between agronomic traits and disease resistance, thus contributing to sorghum improvement efforts. Full article

Chili anthracnose, caused by Colletotrichum truncatum, causes significant yield loss in chili production. In this study, we investigated the elicitor properties of a rhamnolipid (RL)-enriched PA3 fraction derived from Pseudomonas aeruginosa SWUC02 in inducing systemic resistance in yellow chili seedlings and antifungal activity against C. truncatum CFPL01 (Col). Fractionation of the ethyl acetate extract yielded 12 fractions, with PA3 demonstrating the most effective disease suppression, reducing the disease severity index to 4 ± 7.35% at 7 days post-inoculation compared with Col inoculation alone (83 ± 23.57%). PA3 also exhibited direct antifungal activity, inhibiting Col mycelial growth by 41 ± 0.96% at 200 µg/mL. Subfractionation revealed PA3 as a mixture of mono- and di-RLs, confirmed by ¹H nuclear magnetic resonance and electrospray ionization mass spectrometry data. Additionally, PA3 enhanced seed germination and promoted plant growth without causing phytotoxicity. Transcriptomics revealed that PA3 pre-treatment prior to Col infection primed the defense response, upregulating defense-related genes involved in the phenylpropanoid, flavonoid, and jasmonic acid biosynthesis pathways, as well as those associated with cell wall reinforcement. Our findings highlight the potential of RL-enriched PA3 as both an antifungal agent and a plant defense elicitor, with transcriptome data providing new insights into defense priming and resistance pathways in chili, offering an eco-friendly solution for sustainable anthracnose management. Full article

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. Full article

Powdery mildew and anthracnose are the main diseases of rubber trees. In recent years, there have been large outbreaks in the rubber-planting areas of Asia, seriously affecting the yield and quality of rubber latex. ZAR1 is a conserved and distinctive coiled-coil nucleotide-binding leucine-rich (CNL) repeat in the plant kingdom, playing a crucial role in disease-resistance processes. To elucidate the function of the HbZAR1 gene in rubber trees (Hevea brasiliensis), three candidate HbZAR1 genes were identified using bioinformatics methods and comprehensively analyzed. The results indicate that the HbZAR1 protein is conserved in different plant species. Examination of cis-regulatory element sequences of HbZAR1genes reveals that the HbZAR1 gene promoter exhibits a remarkable enrichment of stress, light, and hormone elements. An expression analysis shows that the expression levels of the three HbZAR1 genes are highest in the bark and lowest in latex. Three HbZAR1 genes can respond to both rubber tree Erysiphe quercicola and Colletotrichum siamense infection; especially, HbZAR1.1 and HbZAR1.2 show significant upregulation in expression levels during the early stages of infection. These findings suggest that the three HbZAR1 genes may be involved in rubber tree susceptibility to E. quercicola and C. siamense through different immune mechanisms. Subcellular localization results indicate that the HbZAR1 genes are expressed in the nucleus and plasma membrane. This study also shows that the three HbZAR1 genes and activated mutant HbZAR1.1^D481V do not induce stable ROS production and cell death, suggesting possible gene degradation, functional redundancy, or acting as minor genes in disease resistance. This research provides valuable insights for further studying the function of HbZAR1 genes in rubber trees and the mechanisms of immune molecules. Full article

Anthocyanins, key quality components of tea, act as an important bridge between plants and the environment due to their function on protecting plants from biotic and abiotic irritants. This study aimed to assess the interactions between anthocyanins metabolism and the environment. Purple (P) and green (G) leaves with different anthocyanin contents were inoculated with tea plant anthracnose. High-throughput metabolomics and 16S microbial diversity sequencing methods were used to screen the anthocyanin fractions of tea plant leaves responsive to anthracnose. The interconnections between metabolites and the resistance of phyllosphere microorganisms to fungal pathogens were then analyzed. The results showed that leaves with high anthocyanin content (0.14% of diseased area ratio) were less impacted by anthracnose infestation than leaves with low anthocyanin (3.12%). The cyanidin content decreased after infection in purple leaves (PR) and increased in green leaves (GR). The relative abundance of Cyanobacteria was suppressed by the significant enrichment of Proteobacteria after anthracnose infection in green leaves. However, there were no significant differences between these two groups of microorganisms in purple leaves. Collinear network analysis revealed a strong correlation between Cyanobacteria and Dihydrosorbinol and between Proteobacteria and cyanidin metabolites. Among them, OTU456 (Bosea) was identified as the key taxonomic group of bacterial communities in the green-infected leaf network. In summary, the anthracnose resistance benefits from cyanidin mediated by proteobacteria in tea plants. These results deepen our understanding of the regulation of secondary metabolism in tea plants and the formation of plant resistance. Full article