Colletotrichum Gloeosporioides Research Articles

The endophytic microbiome response patterns of Juglans regia to two pathogenic fungi

The endophytic microbial community reassembles to participate in plant immune balance when the host plants are stressed by pathogens. However, it remains unclear whether this assembly is pathogen-specific and how regulatory pathways are coordinated in multi-pathogens. In order to investigate the effects of infection with Colletotrichum gloeosporioides (Cg treatment) and Fusarium proliferatum (Fp treatment) on walnut leaf endophytic microbiome in their assembly, co-occurrence pattern, and on comprehensive chemical function of the internal environment of leaf, an interaction system of the walnut–pathogenic fungi was constructed using seed embryo tissue culture technology. The study showed differences in the assembly of endophytic microbial communities in walnut trees across three groups (control group, Ck; Cg; Fp) after Cg and Fp treatments. Despite changes in relative abundances, the dominant communities in phyla and genera remained comparable during the infection of the two pathogens. Endophyte fungi were more sensitive to the pathogen challenge than endophyte bacteria. Both promoted the enrichment of beneficial bacteria such as Bacillus and Pseudomonas, changed the modularity of the community, and reduced the stability and complexity of the endophyte community. Pathogenic fungi infection mainly affects the metabolism of porphyrin and chlorophyll, purine metabolism, phenylpropane metabolism, and amino acid metabolism. However, there was no significant difference in the secondary metabolites for the different susceptible plants. By screening endogenous antagonistic bacteria, we further verified that Pseudomonas psychrotolerans and Bacillus subtilis had inhibitory effects on the two pathogenic fungi and participated in the interaction between the leaves and pathogenic fungi. The antibacterial substances may be 1-methylnaphthalene, 1,3-butadiene, 2,3-butanediol, and toluene aldehyde.

Antifungal Capacity of Microcapsules Containing Lactiplantibacillus plantarum TEP15 or Lactiplantibacillus pentosus TEJ4

The use of lactic acid bacteria (LAB) for the biocontrol of fungi that cause fruit and vegetable deterioration is a highly promising strategy. However, one of the main challenges lies in maintaining both viability and antifungal activity even in conditions that are unfavorable for LAB. The microencapsulation of LAB can minimize the impact of environmental conditions, helping to maintain viability, but there is still little information on what occurs with respect to antifungal activity. Therefore, the objective of this study was to evaluate the effect of microencapsulation with several polymer blends on the viability and antifungal activity of Lactiplantibacillus plantarum TEP15 and L. pentosus TEJ4. Sodium alginate (2%), sodium alginate–gum arabic (2%:1%), sodium alginate–k-carrageenan (2%:0.05%), and sodium alginate–whey protein (0.75%:1.5%) were used as encapsulating polymers. After processing (day 0), as well as after 14 and 28 days of storage, the encapsulation efficiency, moisture content, bead size, and survival were evaluated. Likewise, the encapsulated bacteria were subjected to in vitro tests against Colletotrichum gloeosporioides, Penicillium AT21H10, and Fusarium sp. Capsules with sizes ranging from 1.47 mm to 1.88 mm were obtained, and all the wall materials tested had more than 85% encapsulation efficiency and allowed survival rates greater than 90% and 80% to be maintained after 14 and 28 days of storage, respectively. The encapsulated LAB inhibited the growth of mycelia by up to 100%, but, against spores, the greatest inhibition was 22.08% for all the fungi tested.

First Report of Colletotrichum gloeosporioides Causing Anthracnose on Euphorbia lathyris in China.

Euphorbia lathyris L. is a biennial herb in the Euphorbiaceae that has been used as a medicinal plant. It is distributed or cultivated worldwide, and the seeds of E. lathyris are the main source of ingenol, which is the precursor of Picato, the first medicine approved by USFDA for the treatment of solar keratosis (Abramovits et al. 2013). However, the production of E. lathyris can be severely hampered by the occurrence of plant diseases. Between 2020-2022 (specifically in October-November of each year), anthracnose-like symptoms were observed on E. lathyris in fields (E 118°49'50″, N 32°3'33″) in Nanjing, Jiangsu Province, China. The incidence of E. lathyris with disease symptoms was between 25%-30% (n = 100). The lesions on the leaves were evident initially as dark brown spots, which expanded into larger necrotic spots, finally resulting in leaves withering and dropping off. In severe cases, stem wilting was also observed. To determine the causal agent, we collected diseased leaf samples (n = 20) from different E. lathyris plants in the field (~ 1800 m2). After cleaning, the junctions of the diseased and healthy parts were excised and sterilized in 75% ethanol for 20-25 seconds, and rinsed with sterile water. After that, they were transferred onto potato sucrose agar (PSA) plates and placed at 25℃ for 3-4 days, until fungal growth was evident. The fungus was purified by recovering single conidia and growing them on PSA (Hu et al. 2015). A consistent fungal colony, based on morphological characteristics, was recovered from 17 samples. The colony color was initially white, green in the middle, and gradually changed into gray green as the colony matured. Conidia were transparent and cylindrical (22-28 µm × 7-9 µm, n = 50). Five loci informative (ITS, TUB, ACT, GAPDH, and CHS-1) (Weir et al. 2012) for Colletotrichum spp. identification were sequenced from two isolates ELC-1 and ELC-2 obtained from different plant individuals. Compared with a reference isolate (Colletotrichum gloeosporioides ZH3), the GAPDH, CHS-1, and TUB2 sequences of ELC-1 and ELC-2 showed 95% (263 bp out of 275 bp), 98% (295 bp out of 299 bp), and 99% (711 bp out of 712 bp and 717 bp out of 719 bp) similarity, respectively. The ITS sequence identities were 100% (577 bp out of 577 bp) and 99% (594 bp out of 597 bp), while the ACT sequence identities were 100% (281 bp out of 281 bp) and 98% (279 bp out of 284 bp). All sequences have been deposited in Genbank database (OR865865-OR865866 and OR873625-OR873632). After performing phylogenetic analysis with Mega 11, the pathogen was confirmed as C. gloeosporioides. To fulfil Koch's postulates, we sprayed six-week-old healthy plants with a conidia suspension of C. gloeosporioides (106 spores/mL) or sterile water (serve as control). The inoculated plants were placed at 25℃, 100% relative humidity, and 12-h photoperiod (Zhang et al. 2021). Six plants were inoculated for each treatment, and the experiment was repeated three times. After 6-8 days, the plants inoculated with C. gloeosporioides showed similar symptoms to those observed on diseased plants in the field, while the control plants remained healthy and free of disease. The pathogens were then re-isolated and identified as C. gloeosporioides. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose on E. lathyris. Anthracnose may cause significant yield losses in E. lathyris production, and our results will provide experimental and theoretical basis for the management of the disease.

Positive effect of lippia sidoides essential oil associated with carboxymethylcellulose in the control of anthracnose in avocado

The fungus Colletotrichum gloeosporioides, which is the causal agent of anthracnose disease in green-skinned avocados, is responsible for significant postharvest fruit losses. In this context, strategies should be considered to avoid this problem. The use of essential oil (EO) can represent an alternative to contribute to antifungal activity, avoiding the use of chemical products, as their indiscriminate use can have harmful effects on human health. It is known that essential oil (EO) may exhibit antifungal activity and can be used as an alternative to chemical products. Therefore, the potential of using Lippia sidoides EO to control this fungus was investigated through in vitro evaluation (MIC and EC50) on C. gloeosporioides isolated from avocados. Furthermore, the potential of incorporating this oil with carboxymethylcellulose (CMC) for postharvest treatment in avocados was assessed in vivo to control anthracnose and maintain their physicochemical and sensory quality. The EO from L. sidoides demonstrated a MIC of 125 μl L−1 and an EC50 of 46.83 μl L−1 against this pathogen. The results indicated that the CMC edible coating associated with L. sidoides EO exhibited a positive effect on fruit quality during cold storage. In terms of sensory aspects, avocados treated with L. sidoides EO associated with CMC showed improved appearance compared to the control treatment. These findings suggest that L. sidoides EO has potential in the postharvest treatment of avocados. Additionally, these results are significant and unprecedented for this crop, as research on the postharvest effects of incorporating this EO with edible coatings in avocados is still limited.Graphical

Mitigating postharvest quantitative and qualitative losses in mango fruits through the application of biocontrol agents: An in-vivo and in-vitro assessment

Mango is a commercial fruit crop of India that suffers huge postharvest losses every year. The application of biocontrol agents (BCAs) bears a vast potential for managing the same, which is yet to be exploited to its fullest extent. Hence, studies were conducted for BCAs application of Debaryomyces hansenii, Bacillus subtilis and Pseudomonas fluorescens strains on mango fruit under in-vitro, in-vivo conditions to know the efficacy of these BCAs on the postharvest pathogen, shelf life and quality retention of mango fruit. The ‘poisoned food technique’ was attempted for in-vitro studies. For the in-vivo studies, fruit of the commercial cultivar ‘Amrapali’ were un-inoculated and pre-inoculated with major postharvest pathogens (anthracnose: Colletotrichum gloeosporioides and stem-end rot: Botryodiplodia theobromae) were treated with BCA, followed by ambient storage at (24 ± 4 °C, 75 ± 5 % RH). From the results, it has been observed that under in vitro studies, BCA Debaryomyces hansenii (Strain: KP006) and Bacillus subtilis (Strain: BJ0011) at the treatment level 108 CFU mL−1 while, the Pseudomonas fluorescens at 109 CFU mL−1 (Strain: BE0001) were significantly effective for pathogen inhibition. However, under the in vivo studies, the BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL−1 treatment level was found to significantly reduce the pathogen's decay incidence while positively influencing the shelf life and biochemical (quality) attributes. This treatment increased the storage life of mango fruit by more than three days over control fruit. Therefore, BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL−1 can be used to control the postharvest pathological loss of mango fruit without affecting its internal quality.

Biocontrol effectiveness of Trichoderma asperelloides SKRU-01 and Trichoderma asperellum NST-009 on postharvest anthracnose in chili pepper

This study assessed the effectiveness of Trichoderma asperelloides SKRU-01 and Trichoderma asperellum NST-009 in controlling postharvest anthracnose in chili fruits caused by Colletotrichum gloeosporioides PSU-03, using both in vitro assays and studies on chili fruits. In vitro findings indicated that both SKRU-01 and NST-009 exhibited inhibitory effects on PSU-03 through synergistic mechanisms, involving competition for space and nutrients, as well as the production of non-volatile and volatile compounds. Culture filtrates of both strains, at low concentrations (diluted at 1/1000), displayed a robust antifungal effect on PSU-03, achieving over 50% inhibition. This efficacy, however, was lower than that achieved by five chemical fungicides (propiconazole®, prochloraz®, metalaxyl®, azoxystrobin®, and thiram®). The efficacy against anthracnose of SKRU-01 (60.34% protection) and NST-009 (62.07% protection) was significantly higher than metalaxyl®, azoxystrobin®, and thiram®, but lower than propiconazole® and prochloraz®. The two strains demonstrated both preventive and curative effects. Furthermore, results from tests on chili seed germination showed that culture filtrates SKRU-01 significantly inhibited the germination of chili pepper seeds and the growth of seedlings in lab settings. Overall, this study suggests that both SKRU-01 and NST-009 hold the potential for managing postharvest anthracnose in chili fruits caused by C. gloeosporioides. It is crucial to note, however, that culture filtrates SKRU-01 should not be used for biostimulating root development in chili peppers. This research provides valuable insights into the potential application of these biocontrol agents, contributing to enhancing the quality and shelf life of chili produce.

The activity of leaf extracts, fractions, and isolated compounds from Ptaeroxylon obliquum against nine phytopathogenic fungi and the nematode Meloidogyne incognita

Phytopathogenic fungi and nematodes cause great losses in economically important crops and food production especially in developing countries. To minimize the use of fungicides and nematicides, researchers have concentrated on the use of natural products for crop disease prevention or control. The aim of the study was to investigate the antifungal activity of Ptaeroxylon obliquum leaf extracts, fractions, and isolated compounds (obliquumol and a mixture of lupeol and β-amyrin) and nematocidal activity of fractions (hexane, chloroform and 30% water in methanol and the isolated compounds) on Meloidogyne incognita. Nine phytopathogenic fungi (Aspergillus niger, A. parasiticus, Colletotrichum gloeosporioides, Fusarium oxysporum, Penicillium digitatum, P. expansum, P. italicum, P. janthinellum, and Rhizoctonia solani) were used for testing and nematocidal activity was determined on motility of plant parasitic nematode Meloidogyne incognita race 2 juveniles. Serial microdilution test was utilized to determine the minimum inhibitory concentration (MIC) of each sample against the fungus. Motility tests was done on the second-stage juveniles (J2s) of M. incognita. The most susceptible phytopathogenic fungal species to the acetone crude leaf extracts were A. niger, C. gloeosporioides and P. digitatum with MIC of 80 μg/ml which is considered pharmacological significant. Rhizoctonia solani was the most susceptible fungus against obliquumol and, lupeol and β-amyrin mixture with MIC values of 8 μg/ml and 16 μg/ml respectively. Lupeol & β-amyrin mixture had good activity on juvenile motility at high concentrations used which was significantly high (p ≤ 0.05) after 24 h, further incubation resulted in temporary paralysis at lower concentrations. Fractions and obliquumol showed good activity after 48 h, stable paralysis was observed up to 72 h. The extracts and isolated compounds may be useful as fungicides if the in vitro results can be confirmed under field conditions at levels not toxic to beneficial soil organisms.

Penicilloneines A and B, Quinolone-Citrinin Hybrids from a Starfish-Derived Penicillium sp.

Penicilloneines A (1) and B (2) are the first reported quinolone-citrinin hybrids. They were isolated from the starfish-derived fungus Penicillium sp. GGF16-1-2, and their structures were elucidated using spectroscopic, chemical, computational, and single-crystal X-ray diffraction methods. Penicilloneines A (1) and B (2) share a common 4-hydroxy-1-methyl-2(1H)-quinolone unit; however, they differ in terms of citrinin moieties, and these two units are linked via a methylene bridge. Penicilloneines A (1) and B (2) exhibited antifungal activities against Colletotrichum gloeosporioides, with lethal concentration 50 values of 0.02 and 1.51 μg/mL, respectively. A mechanistic study revealed that 1 could inhibit cell growth and promote cell vacuolization and consequent disruption of the fungal cell walls via upregulating nutrient-related hydrolase genes, including putative hydrolase, acetylcholinesterase, glycosyl hydrolase, leucine aminopeptidase, lipase, and beta-galactosidase, and downregulating their synthase genes 3-carboxymuconate cyclase, pyruvate decarboxylase, phosphoketolase, and oxalate decarboxylase.

Diversity of the fungal community on mango associated with stem end rot and anthracnose diseases based on amplicon targeted metagenomics

This study aimed to comprehend the diversity of the fungal community on Chokanan mango, a premium mango variety from Thailand which is widely cultivated in Indonesia, associated with stem end rot and anthracnose disease using high-throughput amplicon targeted metagenomics analysis by next-generation sequencing (NGS). Samples used in this study were freshly harvested healthy fruits at the age of 15-weeks (H15.ITS), healthy fruits after 2 weeks incubation (H17.ITS), 17-week old fruits (S17.ITS) with stem end rot symptoms, and 17-week old fruits (A17.ITS) with anthracnose symptoms. Results showed that the Basidiomycota phylum was dominant in the healthy fruits, while the Ascomycota phylum was found dominantly in sick fruits. Based on OTUs alignment of sequenced data, some species found to be dominantly associated with stem end rot disease in this study were Lasiodiplodia theobromae, Neofusicoccum cordaticola and N. mangiferae. Dominant species which were associated with mango anthracnose disease were Colletotrichum gloeosporioides, Botryosphaeria corticis, Volutella sp., and Pseudofusicoccum violacearum. These fungal genera were not found to be dominant in healthy fruits at the same age indicating that specific genera contributed to developing postharvest diseases on mango differently. The findings confirmed that the fungal community associated with stem end rot and anthracnose disease on mango was unique, and specific species contributed in particular disease development. Since mango is an important global commodity, these research findings will contribute significantly to global biosecurity.

Comparative transcriptome analysis reveals the importance of phenylpropanoid biosynthesis for the induced resistance of 84K poplar to anthracnose

BackgroundPoplar anthracnose, which is one of the most important tree diseases, is primarily caused by Colletotrichum gloeosporioides, which has been detected in poplar plantations in China and is responsible for serious economic losses. The characteristics of 84K poplar that have made it one of the typical woody model plants used for investigating stress resistance include its rapid growth, simple reproduction, and adaptability.ResultsIn this study, we found that the resistance of 84K poplar to anthracnose varied considerably depending on how the samples were inoculated of the two seedlings in each tissue culture bottle, one (84K-Cg) was inoculated for 6 days, whereas the 84K-DCg samples were another seedling inoculated at the 6th day and incubated for another 6 days under the same conditions. It was showed that the average anthracnose spot diameter on 84K-Cg and 84K-DCg leaves was 1.23 ± 0.0577 cm and 0.67 ± 0.1154 cm, respectively. Based on the transcriptome sequencing analysis, it was indicated that the upregulated phenylpropanoid biosynthesis-related genes in 84K poplar infected with C. gloeosporioides, including genes encoding PAL, C4H, 4CL, HCT, CCR, COMT, F5H, and CAD, are also involved in other KEGG pathways (i.e., flavonoid biosynthesis and phenylalanine metabolism). The expression levels of these genes were lowest in 84K-Cg and highest in 84K-DCg.ConclusionsIt was found that PAL-related genes may be crucial for the induced resistance of 84K poplar to anthracnose, which enriched in the phenylpropanoid biosynthesis. These results will provide the basis for future research conducted to verify the contribution of phenylpropanoid biosynthesis to induced resistance and explore plant immune resistance-related signals that may regulate plant defense capabilities, which may provide valuable insights relevant to the development of effective and environmentally friendly methods for controlling poplar anthracnose.

CgNis1's Impact on Virulence and Stress Response in Colletotrichum gloeosporioides.

Pepper anthracnose caused by Colletotrichum gloeosporioides infection is an important fungal disease and represents a serious threat to pepper yield and quality. At present, the pathogenic molecular mechanism of C. gloeosporioides is not very clear. In our study, we characterized the function of C. gloeosporioides CgNis1, a homolog of Magnaporthe oryzae MoNis1. We found that the ∆Cgnis1 mutant reduced the growth rate and was defective in conidiation. Although the rate of appressorium formation was unaffected, the germ tube was found to be abnormal. CgNis1 was shown to be involved in the H2O2 stress response and maintaining cell membrane permeability. The pathogenicity assays performed in this study indicated that the deletion of CgNIS1 is associated with virulence. Our results indicate that CgNis1 is necessary for the growth, development, and pathogenicity of the fungus. This work provides an in-depth analysis of the Nis1 protein, helps to enhance studies on pathogen-related molecular mechanisms, and provides a theoretical basis for the prevention and control of C. gloeosporioides in peppers.

The Laccase Family Gene CsLAC37 Participates in Resistance to Colletotrichum gloeosporioides Infection in Tea Plants

Fungal attacks have become a major obstacle in tea plantations. Colletotrichum gloeosporioides is one of the most devastating fungal pathogens in tea plantations that can severely affect tea yield and quality. However, the molecular mechanism of resistance genes involved in anthracnose is still largely unknown in tea plants. Here, we found that the laccase gene CsLAC37 was involved in the response to fungal infection based on a transcriptome analysis. The full-length CDS of CsLAC37 was cloned, and its protein sequence had the closest relationship with the Arabidopsis AtLAC15 protein compared to other AtLACs. Tissue-specific expression analysis showed that CsLAC37 had higher expression levels in mature leaves and stems than in the other tissues. Subcellular localization showed that the CsLAC37 protein was predominantly localized in the cell membrane. The expression levels of CsLAC37 were upregulated at different time points under cold, salt, SA, and ABA treatments. qRT-PCR confirmed that CsLAC37 responded to both Pestalotiopsis-like species and C. gloeosporioides infections. Functional validation showed that the hydrogen peroxide (H2O2) content increased significantly, and POD activity decreased in leaves after antisense oligonucleotide (AsODN) treatment compared to the controls. The results demonstrated that CsLAC37 may play an important role in resistance to anthracnose, and the findings provide a theoretical foundation for molecular breeding of tea varieties with resistance to fungal diseases.

First Report of Neoscytalidium dimidiatum causing leaf zonate spot disease of Aloe vera L. in China.

In February 2022, leaf zonate spot disease afflicted Aloe vera L. in Yunnan, China, endangering the $39 billion industry with 0.33ha under cultivation (Wan 2015). The disease manifested with watery spots progressing into oval or circular necrosis lesions, characterized by a dark center surrounded by a gray-brown zone. In the late stage of the disease, lesions regress in size and several small dark picnidia dots appeared on the gray-brown zone. The disease incidence ranged from 10% to 15% in three commercial plantations. If left uncontrolled, the disease could diminish the commercial value of Aloe vera plants. Eighteen symptomatic leaf samples underwent morphological and genetic identification. The samples were carefully washed with distilled water and 1×1 cm2 sections of tissue were excised using a sterile scalpel. The sections underwent surface-disinfection with 3% NaOCl for 3 min and 75% ethanol for 30 s. After three sterile water rinses the sections were air-dried. Subsequently, they were transferred to potato dextrose agar (PDA) before being incubated at 25 ℃ in the dark. Of the 18 samples, eight produced the colonies with similar morphological characteristics, named LH7. Isolate LH7 had downy to woolly aerial mycelia, initially pinkish white on the surface, and gradually turned greenish-olivaceous from the middle, and eventually turned dark brown to black after seven days. The fungus formed arthric chains in the aerial mycelium on PDA but did not produce conidiomata. The conidia, which occurred in arthric chains were 5.50-9.9 × 4.08-7.51 μm (mean 7.09× 5.26 μm, n=50) in size, cylindrical, brown, and 0-1 septate. To ascertain LH7's pathogenicity, three healthy one-year old aloe plants were surface-sanitized with a 1% aqueous chlorine solution, rinsed with sterile water, and dried. Three leaves from each plant were punctuated and inoculated using conidial suspension (100 μl of 1x 106 conidial mL-1), while three control plants were inoculated with sterile distilled water. The pathogenicity tests were repeated twice. The inoculated plants were kept at 25 ℃ with a 12-hour light/12-hour dark cycle. After seven days, symptoms observed in the field appeared in the plants, while no disease occurred in the control plants. After 21 days, conidiomata formed on the inoculated leaves, averaging 116.92 μm (n=20) in diameter. These conidiomata were globose to subglobose, and brown to sub-brown. The fungus was successfully re-isolated from symptomatic tissue and the resulting colonies were morphologically consistent with isolate LH7. Based on the characteristics, the fungus was identified as Neoscytalidium dimidiatum (Philips et al. 2013). The specimen was deposited in China Center for Type Culture Collection ( CCTCC AF 2024001). This identification was confirmed through sequencing of ITS gene region of rDNA using ITS1/ITS4 (Imran et al. 2022). The sequence was submitted into GenBank database (ON878059). BLAST analysis of the LH7's ITS amplicon showed 100% similarity with that of JN093303.1. A phylogenetic tree constructed using the maximum likelihood method revealed that ON878059 was clustered with JN093303.1. Previous studies have documented that pathogens such as Colletotrichum gloeosporioides (Penz.), Fusarium spp. and Rhizopus oryzae can also cause diseases in A. vera in China (Zhou et al. 2008; Ding et al. 2015). Additinonally, Cladosporium sphaerospermum, Pseudopestalotiopsis theae, and Lasiodiplodia theobromae have been identified as causal agents of aloe leaf spot diseases in India, Bangladesh and Malaysia (Avasthi et al. 2016; Ahmmed et al. 2022; Khoo et al. 2022). To our knowledge, this is the first report of N. dimidiatum causing leaf necrosis of aloe in China. Vigilant surveillance and disease control measures are imperative to mitigate potential losses in this region.

Assessment of cytotoxic and genotoxic effects of Colletotrichum gloeosporioides and C. capsici toxins on tobacco BY-2 cells

Assessment of cytotoxic and genotoxic effects of Colletotrichum gloeosporioides and C. capsici toxins on tobacco BY-2 cells

Comprehensive antifungal investigation of green synthesized silver nanoformulation against four agriculturally significant fungi and its cytotoxic applications

The present study reports the green synthesis of silver nanoparticles (AgNPs) in powder form using the leaf extract of Azadirachta indica. The synthesis of AgNPs was confirmed by UV–vis spectroscopy, FTIR, XRD, FESEM, and EDX. The synthesized AgNPs were in a powdered state and dispersed completely in 5% polyethylene glycol (PEG) and demonstrated prolonged shelf life and enhanced bioavailability over a year without any aggregation. The resulting silver nanoformulation demonstrated complete inhibition against Sclerotinia sclerotiorum and Colletotrichum falcatum and 68% to 80% inhibition against Colletotrichum gloeosporioides and Rhizoctonia solani respectively, at 2000 ppm. The EC50 values determined through a statistical analysis were 66.42, 157.7, 19.06, and 33.30 ppm for S. sclerotiorum, C. falcatum, C. gloeosporioides, and R. solani respectively. The silver nanoformulation also established significant cytotoxicity, with a 74.96% inhibition rate against the human glioblastoma cell line U87MG at 250 ppm. The IC50 value for the cancerous cell lines was determined to be 56.87 ppm through statistical analysis. The proposed silver nanoformulation may be used as a next-generation fungicide in crop improvement and may also find application in anticancer investigations. To the best of our knowledge, this is also the first report of silver nanoformulation demonstrating complete inhibition against the economically significant phytopathogen C. falcatum.

Prospecting the Effectiveness of Fungicides and Bioagents against Colletotrichum gloeosporioides (Penz.) Penz & Sacc.

Aims: The leaf spot caused by Colletotrichum gloeosporioides (Penz.) Penz & Sacc. is one of the most serious disease in all mango growing regions of the world. In vitro bioassay of fungicides and bioagents were performed to evaluate the effectiveness of different fungicides and bioagents against C. gloeosporioides.
 Study Design: Poison food techique for fungicides bioassay and dual culture technique for bioagents bioassay.
 Place and Duration of Study: The laboratory studies were conducted in the Department of Plant Pathology, N. M. College of Agriculture, Navsari Agricultural University, Navsari, Gujarat, India during 2020–2021.
 Methodology: The poison food technique assessed the efficacy of systemic, contact and combination fungicides against C. gloeosporioides. While the dual culture method was employed to gauge the potency of biocontrol agents, against C. gloeosporioides. 
 Results: In laboratory screening, systemic fungicides such as carbendazim and difenconazole were shown to have 100% growth suppression at 500 ppm. Mancozeb and copper oxychloride, two contact fungicides, demonstrated 100% growth inhibition of C. gloeosporioides at 2500 ppm . The combi-product fungicides tricyclazole 18% + mancozeb 62%, hexaconazole 4% + zineb 68%, and carbendazim 12% + mancozeb 63% were shown to exhibit 100% growth inhibition at 2000 ppm. Using the dual culture method, five distinct bioagents were tested in vitro for their ability to prevent the development of C. gleosporiodes. Trichoderma harzianum showed up as one of them to be a powerful and effective antagonist of C. gleosporiodes.
 Conclusion: In vitro fungicide and bioagent testing provides preliminary data on the effectiveness of fungicides against pathogens, guiding field testing. The study evaluated the effectiveness of fungicides and bioagents in suppressing the leaf spot pathogen of mango.

Evaluating Pomegranate Cultivars for Resistance to Anthracnose Fruit Rot, a Severe Fungal Disease in Florida and Southeast United States

Pomegranate (Punica granatum L.) has primarily been cultivated at home in Florida and other southeastern states. Over the past 15 years, growers, nurseries, researchers, and Extension agents have explored the potential of pomegranate as an alternative fruit crop. Early field trials revealed that pomegranates are highly susceptible to Colletotrichum gloeosporioides, causing severe anthracnose fruit rot and premature fruit drop. The development and use of disease-resistant cultivars are considered some of the best methods to manage this disease. This publication presents our findings from evaluating 35 pomegranate cultivars under natural disease pressure in central Florida and by artificial inoculation. The susceptibility of such pomegranate cultivars varied widely, with six exhibiting resistance to anthracnose fruit rot. More comprehensive research is warranted to further develop anthracnose-resistant cultivars and to enhance our understanding of disease resistance in this crop.

Roles of CgEde1 and CgMca in Development and Virulence of Colletotrichum gloeosporioides.

Anthracnose, induced by Colletotrichum gloeosporioides, poses a substantial economic threat to rubber tree yields and various other tropical crops. Ede1, an endocytic scaffolding protein, plays a crucial role in endocytic site initiation and maturation in yeast. Metacaspases, sharing structural similarities with caspase family proteases, are essential for maintaining cell fitness. To enhance our understanding of the growth and virulence of C. gloeosporioides, we identified a homologue of Ede1 (CgEde1) in C. gloeosporioides. The knockout of CgEde1 led to impairments in vegetative growth, conidiation, and pathogenicity. Furthermore, we characterized a weakly interacted partner of CgEde1 and CgMca (orthologue of metacaspase). Notably, both the single mutant ΔCgMca and the double mutant ΔCgEde1/ΔCgMca exhibited severe defects in conidiation and germination. Polarity establishment and pathogenicity were also disrupted in these mutants. Moreover, a significantly insoluble protein accumulation was observed in ΔCgMca and ΔCgEde1/ΔCgMca strains. These findings elucidate the mechanism by which CgEde1 and CgMca regulates the growth and pathogenicity of C. gloeosporioides. Their regulation involves influencing conidiation, polarity establishment, and maintaining cell fitness, providing valuable insights into the intricate interplay between CgEde1 and CgMca in C. gloeosporioides.

Unveiling the potential of Daldinia eschscholtzii MFLUCC 19-0629 through bioactivity and bioinformatics studies for enhanced sustainable agriculture production

Endophytic fungi constitute a rich source of secondary metabolites that can be manipulated to produce desirable novel analogs for combating current agricultural challenges for crop production, especially controlling plant disease. The endophytic fungus Daldinia eschscholtzii MFLUCC 19-0629, was newly isolated from tropical ancient plants, Oncosperma sp., and displays a broad-spectrum of antifungal and antibacterial activities against several plant pathogens including Ralstonia solanacearum, Fusarium oxysporum, Colletotrichum gloeosporioides, Colletotrichum acutatum, Stagonosporopsis cucurbitacearum, Corynespora cassiicola and Stemphylium spp. A high-quality genome sequence was obtained using Oxford nanopore technology, the accuracy and length of reads resulting in no need for Illumina or other sequencing techniques, for D. eschscholtzii MFLUCC 19-0629, resulting in a genome size of 37.56 Mb assembled over 11 contigs of significant size, likely to be at the chromosomal level. Bioinformatics analysis revealed that this strain is biosynthetically talented encoding 67 predicted biosynthetic gene clusters (BGCs). Only eight of the 67 BGCs matched or demonstrated high similarity to previously characterized BGCs linked to the production of known secondary metabolites. The high number of predicted unknown BGCs makes this strain a promising source of novel natural products. The discovery that D. eschscholtzii MFLUCC 19-0629 has a broad spectrum of antimicrobial activity against seven major plant pathogenic microorganisms relevant to crop production and its complete genome sequence carries immense importance in the advancement of novel microbial biocontrol agents (MBCAs). This also unveils the prospect of uncovering new compounds that could be utilized for sustainable agriculture and pharmaceutical purposes.

Response of Bacillus velezensis 83 to interaction with Colletotrichum gloeosporioides resembles a Greek phalanx-style formation: a stress resistant phenotype with antibiosis capacity

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