Colletotrichum scovillei is a major fungal pathogen responsible for anthracnose disease, posing a growing threat to global chili production. Mefentrifluconazole, a novel isopropanol-triazole fungicide, exhibits strong efficacy against a broad spectrum of plant pathogens. However, the resistance risk of mefentrifluconazole in Colletotrichum scovillei and the associated molecular mechanisms remain poorly characterized. In this study, we evaluated the sensitivity of 102 Colletotrichum scovillei isolates to mefentrifluconazole, revealing a half-maximal effective concentration (EC50) value of 0.6924 ± 0.1482 μg mL-1. Through fungicide adaptation, seven stable resistant mutants were generated from four sensitive parental isolates, with resistance factors ranging from 3.73 to 26.51. Compared to their parental isolates, the resistant mutants displayed similar or reduced fitness in terms of growth, sporulation and pathogenicity. Cross-resistance assays indicated that mefentrifluconazole exhibited positive cross-resistance with difenoconazole, propiconazole and prochloraz, but not with pyraclostrobin, florylpicoxamid or fluazinam. Further biochemical analysis demonstrated that mefentrifluconazole treatment resulted in a significantly higher inhibition rate of ergosterol biosynthesis in parental isolates relative to resistant mutants. A similar finding was observed in cell membrane damage assessment. Molecular investigations revealed no mutations in CYP51 paralogs among resistant mutants; however, quantitative analysis confirmed the overexpression of CYP51 paralogs in these isolates following mefentrifluconazole exposure. Together, there is a low risk of Colletotrichum scovillei developing resistance to mefentrifluconazole, and the induced overexpression of CYP51 paralogs may contribute to potential mefentrifluconazole resistance in this pathogen. These findings offer significant implications for formulating effective management strategies against anthracnose. © 2025 Society of Chemical Industry.

Pepper anthracnose, caused by Colletotrichum scovillei, is one of the most destructive diseases threatening pepper production in Korea. Detached pepper fruits are commonly used for pathogenicity assays; however, obtaining fruits through plant cultivation requires substantial time and labor. Although commercial fruits can serve as alternatives, essential meta-information—such as cultivar, post-harvest storage duration, and potential chemical residues—is typically unavailable, often resulting in non-reproducible pathogenicity assay outcomes. To address this limitation, we developed a detached leaf pathogenicity assay that offers applicability and consistency comparable to the fruit assay. Using 3-week-old pepper seedlings, we evaluated the effects of conidial suspension concentration, temperature, and incubation period on the pathogenicity of C. scovillei. Under optimal conditions of a 106 spores/ml conidial suspension, incubation at 25 o C, and evaluation at 7 days post inoculation, the detached leaf assay showed no statistically significant differences from the fruit assay. We further assessed its feasibility for fungicide efficacy testing by examining the effects of fungicide concentration and spray timing on control efficacy. Taken together, these results support the detached leaf assay as an efficient and reproducible alternative to the fruit assay for evaluating the pathogenicity of C. scovillei.

Olive anthracnose is a major disease worldwide; although once chiefly attributed to Colletotrichum acutatum, it is now clear that the predominant pathogen varies among regions. In this study, we identified Colletotrichum scovillei for the first time as a latent pathogen in olive fruits from groves in the Peloponnese, Greece, expanding the known diversity of Colletotrichum species associated with olive anthracnose. To better understand the ecological context of this finding, we examined the role of endophytic microorganisms in olive tissues and their interactions with phytopathogens. Endophytic fungi isolated from asymptomatic ripe olive fruits and leaves were characterized for phylogeny and potential pathogenicity, while competitive interactions between Colletotrichum species and other endophytes were assessed to identify potential biological control agents. In parallel, meteorological variability among sampling sites was analyzed to explore possible links with pathogen distribution. Our results indicate that naturally occurring endophytes sharing the Colletotrichum niche can suppress the necrotrophic phase of Colletotrichum spp., supporting the potential of such endophytes as sustainable tools for disease management. We detected C. scovillei in asymptomatic olives in one sampling year and confirmed its virulence via inoculation assays. This temporally limited yet virulent occurrence, alongside the activity of resident endophytes, supports an integrated, ecology-informed approach to anthracnose management.

Streptomyces olivoreticuli ZZ-21 act as a potential biocontrol strain against pepper anthracnose caused by Colletotrichum scovillei.

Pepper anthracnose, caused predominantly by <i>Colletotrichum scovillei</i>, is one of the most economically significant diseases affecting <i>Capsicum annuum</i> cultivation in Korea. While systemic fungicides such as tebuconazole (demethylation inhibitors) and azoxystrobin (quinone outside inhibitors) are commonly used, resistance development has raised concerns regarding their long-term efficacy. This study evaluated the control efficacy of different fungicide treatment strategies under field conditions, including single and alternating applications of chlorothalonil, tebuconazole, and azoxystrobin, with varying spray intervals (7-9 vs. 14-16 days). Unexpectedly, chlorothalonil applied alone at a short interval (7-9 days) showed the highest disease control efficacy (77.2%), outperforming all alternating treatments. These results suggest that frequent application of chlorothalonil may provide effective disease control under the specific field conditions tested. However, this study did not assess fungicide resistance in the field pathogen population, which limits the applicability of the findings to other regions or conditions. Further research including resistance monitoring is needed to validate the broader applicability of this approach for pepper anthracnose management.

This study aimed to investigate the potential of plant-associated bacteria as bio-control agents for the green bell pepper rot lesion caused by Colletotrichum scovillei 244830. A total of 378 bacteria strains isolated from stems and leaves of healthy red chili and tomato were tested for their antagonistic potential. Isolate TS001 associated with tomato stems was identified as Bacillus spp. It was found that TS001 showed remarkable inhibition to C. scovillei 244830 in in vitro and in vivo tests. TS001 significantly reduced rot lesions (p < 0.05) of fresh green bell pepper fruits by 71.43%. Furthermore, the result of the LC-ESI-MS/MS showed that the culture broth of the strain Bacillus sp. TS001 contained iturin and surfactin homolog in No. 3S medium. TS001 exhibited the strongest antagonistic activity that effectively suppressed C. scovillei 244830 rot lesion.

Green fruit anthracnose caused by the fungus Colletotrichum scovillei is an emerging disease on various types of peppers (Capsicum spp.) in the eastern United States. Sixteen cultivars, representing 11 horticultural fruit types from four species of Capsicum, C. annuum, C. baccatum, C. chinese, and C. frutescens, were evaluated for potential fruit rot resistance to C. scovillei in replicated field plots in summer 2022 and 2023. Fruit was naturally inoculated by facilitating spread of conidia of C. scovillei with overhead irrigation from inoculated jalapeño fruit on plants located between plots into test plots. C. chinense cultivars Roulette and Carolina Reaper and C. frutescens cultivars Tabasco and Malagueta had significantly lower fruit disease incidence than the other 12 cultivars in both years. In a second experiment, conducted in fall 2022 and 2023, four C. annuum pepper types were treated or not treated with a preventative rotation of mancozeb and azoxystrobin at labeled rates. The fungicide treatment reduced fruit disease incidence fivefold compared to the nontreated control in both years. In the nontreated plots, the reduced susceptibility of jalapeño, New Mexico chili, and Italian frying peppers provided 50% fruit rot control relative to susceptible bell pepper. In fungicide-treated plots, however, mean percentage control was 80% for the non-bell cultivars. In 2022, marketable weight and number were fivefold greater on fungicide-treated plants than non-treated plants, but in 2023, yields were not affected by fungicides. C. frutescens may be useful as a source of resistance to develop new pepper cultivars that would help growers manage green fruit anthracnose.

Virulence assay is an essential step to determine the severity of pathogen infection. The virulence assay of Colletotrichum scovillei originating from Magelang Regency was conducted on several chili varieties, namely OR Twist 42, Mahkota, and Pillar F1. This study investigated the virulence of Colletotrichum scovillei on different chili varieties through in vivo inoculation. The experiment was conducted from July to October 2024 at Bandongan Teaching Farm greenhouse, Drojogan, Bandongan District, Magelang Regency (altitude: 431 m above sea level). A completely randomized block design with single factor and four replications was employed. Data were analyzed using analysis of variance followed by 1% BNT test. Colletotrichum scovillei inoculation significantly affected leaf count, incubation period, disease incidence, disease severity, and fruit weight parameters, but not plant height. Characteristic anthracnose symptoms appeared as irregular brown lesions with dark margins on leaf surfaces. Disease incidence remained at mild levels across all varieties, with Mahkota showing the highest infection rate(2.03%), followed by Pillar F1 (1.85%) and OR Twist 42 (1.79%). All varieties showed mild disease severity OR Twist 42 (0.19%), Mahkota (0.24%), and Pillar F1 (0.23%).

Pepper anthracnose caused by Colletotrichum scovillei is a destructive disease. Currently, anthracnose diseases are primary controlled using fungicides, but prolonged overuse of conventional chemical fungicides can adversely affect both the environment and human health. Thus, it is essential to explore safer alternative methods for controlling pepper anthracnose to mitigate environmental and food safety risks. One promising strategy is biocontrol utilizing Bacillus species. We identified the Bacillus velezensis strain LQ-03, which demonstrated significant antagonistic activity against C. scovillei and various other plant pathogens. LQ-03 exhibited effective control of pepper anthracnose and enhanced the activities of defense enzymes in pepper fruit. The crude protein extracts of LQ-03 significantly inhibited mycelial growth, conidial germination and viability, disrupted the morphological structure and cell membrane integrity, and induced reactive oxygen species (ROS) accumulation in C. scovillei. The crude protein extracts effectively reduced the progression of anthracnose on pepper fruit. Transcriptome analysis revealed that the extracts exert antifungal activity by reprogramming multiple metabolic pathways, particularly those involved in energy conversion. Several biosynthetic gene clusters (BGCs) potentially responsible for the synthesis of bioactive compounds were predicted from the LQ-03 genome. Our results showed that LQ-03 is a promising biocontrol agent against anthracnose caused by C. scovillei in pepper, providing a theoretical basis for development as a natural fungicide. © 2025 Society of Chemical Industry.

Selection of a reliable internal control gene is critical for quantitative real-time PCR, which is a rapid, highly sensitive, and easy method for evaluating gene expression levels in different samples or tissues. Colletotrichum scovillei, which belongs to the C. acutatum species complex, is a common and aggressive species that can cause anthracnose in chili peppers. However, stable reference genes have not yet been identified for C. scovillei. In our study, reference genes were selected and validated in C. scovillei during different growth stages, including conidia, conidial germination, and mycelium growth, during host interactions, and after treatment with the common solvent 0.5% dimethyl sulfoxide (DMSO) and plant extracts with antifungal activity against C. scovillei. Eight candidate reference genes (CsUCE, CsCK, CsTBP, CsTIF, CsPP2A, CsTUB, CsCAL, and CsNADH) were selected from C. scovillei based on transcriptomic and genomic data. Several statistical methods, including the comparative quantification cycle threshold (Ct) method, geNorm, NormFinder, and Bestkeeper, were used to assess the stabilities of reference gene transcripts. The results indicated that CsPP2A had better stability during the C. scovillei growth stage, CsTUB had the best stability during host interactions, and CsUCE was more stable after treatment with the general solvent 0.5% DMSO and Cestrum glanduliferum kerber ex Francey extracts. Our study provides the most suitable reference gene for future studies to quantify target gene expression levels in C. scovillei under different conditions.

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.

Clausena lansium (Lour.) Skeels is a tropical and subtropical plant species, it is not only a fruit but also has medicinal value. Its cultivated areas are mainly distributed in Guangdong, Guangxi, Fujian, and Hainan provinces in China. A severe anthracnose disease was observed during surveys of Clausena lansium disease in Yanfeng town of Hainan province in June 2024. The acreage of plantation was 2 acres. The percentage of symptomatic plants was about 70%. Symptoms appeared both on leaves and young shoots. Lesions appeared as brown point-sized at first on the leaf, and then enlarged to dark brown irregular lesions lined by a yellow halo. Diseased leaves became distorted and wrinkled at last. On young shoots, lesions appeared as water-soaked at first, and then enlarged to dark brown and sunken, ultimately leading to dieback. Five symptomatic leaves were sampled from different trees for pathogen isolation. 15 small pieces (5 mm) of necrotic tissue were removed from the border between symptomatic and healthy tissue, surface sterilized for 1 min in 1.5% NaOCl, washed three times with sterile distilled water, and plated onto potato dextrose agar (PDA). The plates were incubated at 28°C for five days. We obtained 10 Colletotrichum isolates with similar colony morphology. For a pure culture of the isolate, spore masses were picked off with a sterilized wire loop and streaked on the surface of water agar. After incubation overnight at 25 °C, single germinated spores were picked up with a sterile needle and transferred to PDA. Identification of the isolate was based on morphological as well as molecular characterisation. Colony characters and microscopic morphology characteristics of isolates were observed after growth on PDA at 28°C under dark for 7 days. The colonies on PDA were white at first, and then turned dark gray, cottony, with orange conidiomata, reverse dark gray to black at the center. Conidiophores formed on a cushion of medium brown roundish cells. Conidiophores were hyaline, Conidiogenous cells were cylindrical to ampulliform, straight to flexuous, 33-51 μm. Conidia were hyaline, aseptate, cylindrical with round ends, smooth-walled, guttulate, 9.9-19.9× 4.7-6.0 μm (mean ± SD = 12.8 ± 2.8 × 5.4 ± 0.4 μm, n=50). Genomic DNA of the 10 isolates was extracted from the culture, and DNA sequencing of an intron of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUB2), actin (ACT), chitin synthase 1 (CHS-1), and the internal transcribed spacer (ITS) was conducted to accurately identify the species. ITS, TUB2 and ACT sequences from the ten isolates shared 100% identity, GAPDH and CHS-1 shared 99.6% identity. Sequences of the isolate named HPCS1 were deposited in GenBank (ITS Accession Nos. PQ113778; TUB2 Accession Nos: PQ133411; GAPDH Accession Nos: PQ137484; ACT Accession Nos: PQ782238, CHS-1 Accession Nos: PQ782239, respectively). ITS (513bp) of the Clausena lansium isolate HPCS1 were 100%, and GAPDH (232bp/234bp), ACT (256bp/257bp), CHS-1 (215bp/216bp) and TUB2 (419bp/420bp) were more than 99% similar with the Colletotrichum siamense type strain CBS130417 (Prihastuti et al. 2009) (GenBank Accession Nos. JX010171, JX009924, and JX010404) (Weir et al. 2012). In the phylogenetic analysis, the 10 isolates formed a monophyletic group and clustered within a clade with the ex-type isolate of Colletotrichum siamense (Sharma et al. 2015; Liu et al. 2016). Based on morphological and multilocus phylogeny, the Clausena lansium isolates were identified as C. siamense. To confirm pathogenicity, a conidial suspension (1 × 106 conidia/ml) of HPCS1 isolate was prepared by harvesting conidia from 10-day-old cultures growing on PDA and 5 mL was sprayed onto the healthy young shoots with tender leaves without wounding. All 9 young shoots inoculated were covered with plastic bags for 48 h to maintain high humidity and incubated at 28°C (Lin et al. 2020). After 5 days, symptoms were observed on the C. lansium leaves and were similar to those observed on the naturally infected plants. No symptoms were observed on the control leaves (inoculated with sterilized water in the same way). The pathogen was re-isolated from symptomatic tissues, but not from controls. These re-isolates matched the morphological and molecular characteristics of the original isolates, fulfilling Koch's postulates. C. siamense was described from Coffea arabica in Thailand (Prihastuti et al. 2009). In China, Colletotrichum scovillei was reported as a pathogen causing anthracnose on C. lansium (Lin et al. 2020). To our knowledge, this is the first report of C. lansium anthracnose causing by C. siamense.

First report of Colletotrichum scovillei associated with anthracnose of chilli in Mauritius

Banana (Musa spp.) is widely cultivated as the major fruit in Pakistan. Anthracnose fruit rot caused by various Colletotrichum spp. is a serious disease. Sample of 23 banana fruits were obtained from 4 commercial orchards (43% incidence) in Uthal, Balochistan, Pakistan. One or more small light-brown to reddish-brown spots were observed on all fruits during early stage of infection and later became sunken lesion. The pieces of diseased tissues were cut from margins, surface sterilized with sodium hypochlorite (0.3%), rinsed in sterile distilled water, dried on sterile filter papers and shifted on potato dextrose agar (PDA). Colony morphology of all isolates (n=21) on PDA were white fungal colonies which became dark gray after 7 days. Smooth, aseptate, cylindrical and hyaline conidia (n=20 per isolate) were recorded and measured 10.2 to 16.1 (avg. 12.3) × 3.7 to 4.5 (avg. 3.8) µm. Genomic DNA was extracted from a representative isolate LUAWMS and sequences from the internal transcribed spacer region (ITS), β-tubulin (TUB2), calmodulin (CAL), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), actin (ACT) and chitin synthase 1 (CHS-1) genes were amplified through polymerase chain reaction with the primer pairs ITS1/ITS4, BT1/BT2, CAL1/CAL2, GAPDH1/DAPDH2, ACTN1/ACTN2 and CHS1/CHS2, respectively. The sequences were exhibiting 100% genetic similarity with previously reported isolates SPTD26 (ITS, accession no PQ780054), PHL6, (TUB2, accession no KY475555), HNCS015 (CAL, accession no KX673577), Cer015 (GAPDH, accession no MK473911), QJ2_1 (ACT, accession no OQ613619) and CAUA43 (CHS-1, accession no KP145299) of Colletotrichum scovillei. ITS, TUB2, CAL, GAPDH, ACT and CHS-1 multi-locus sequences were deposited in GenBank under the accession numbers OK493385, OK493386, OK493387, OR449357, OR449358 and OR449359, respectively. For the confirmation of Koch's postulates, banana fruits (n=3) were surface sterilized with 70% ethanol, washed with sterile distilled water and wounded with the help of sterile needle. The spore suspension (1 × 106 conidia/mL) from LUAWMS were pipetted (10 µL) on wound fruit and incubated at 28°C with 12 h dark and light cycle. Moist paper towels was placed on bottom of a sealed crisper box and artificially inoculated fruits were shifted to a humid chamber. Three replicate boxes each contained one banana per treatment. Sterile distilled water was used as a negative control and the experiment was repeated once. After 7 days, small light-brown to reddish-brown spots (length averaged 14.9 mm, std. dev. = 4.0 mm) by 11.3 mm (std. dev. = 1.9 mm) were recorded on artificially inoculated fruits but not on control. Same pathogen was re-isolated from artificially inoculated fruit on PDA and morphological examination and molecular identified was used for the confirmation as previously described. Morphological characterization, molecular identification, multi-locus sequence analysis and Koch postulates confirmed LUAWMS as C. scovillei belongs to C. acutatum species complex (Damm et al., 2012). Previously, C. scovillei was recorded as causal organism of anthracnose disease of banana in China (Zhou et al., 2017), Watermelon in Malaysia (Goh et al., 2022) and pepper in Ontario, Canada (Ellouze, 2024) but to our knowledge, this is the first report of C. scovillei causing anthracnose of banana in Balochistan, Pakistan. The new host-pathogen association could lead to reduced banana yields, higher management costs, and potential trade disruptions due to disease spread and export restrictions.

ABSTRACTColletotrichum scovillei causes anthracnose in chilli pepper worldwide, which is one of the most serious diseases affecting the production of pepper fruits. Although there are several studies on the Colletotrichum disease genes identified, there are still gaps in the understanding of the pathogenic genes and pathogenic mechanisms of Colletotrichum. In this study, two Colletotrichum strains, C. scovillei (Colletotrichum scovillei) C1 and C. scovillei CD showed different virulence against chill pepper, with C. scovillei C1 having a marked virulence defect compared to C. scovillei CD. To explore the genetic variation between the two strains, comparative genomic and transcriptome analyses were conducted to reveal the functional genes associated with the virulence. At the genome level, C. scovillei C1 was found to have a number of structural variation (SVs), insertion and deletion (InDels) and single nucleotide polymorphisms (SNPs) compared with C. scovillei CD. Analysis of DEGs (differentially expressed genes) between C. scovillei C1 and C. scovillei CD at the transcriptome level revealed 106 DEGs, including three upregulated effectors in C. scovillei CD, which might be the reasons for the high virulence of C. scovillei CD. In summary, our study revealed the genomic and transcriptomic mechanism involved in C. scovillei virulence in pepper, which contributes to the understanding of pepper anthracnose pathogenicity.

Physiological Biochemistry and Multi-omics Reveal the Underlying Mechanism of Citral in Controlling Colletotrichum scovillei in Postharvest Chili

Chili anthracnose, a fungal disease caused by Colletotrichum scovillei, is among the most devastating diseases affecting pepper (Capsicum annuum L.). Although WRKY transcription factors play important roles in plant immunity, it is unknown how WRKY gene family members contribute to pepper plant resistance to C. scovillei. Here, CaWRKY20 was found to negatively regulate pepper resistance to C. scovillei, which was demonstrated by virus-induced gene silencing and transient overexpression in pepper. Moreover, overexpression of CaWRKY20 enhanced susceptibility to C. scovillei in tomato. Additionally, our findings demonstrated that CaWRKY20 can indirectly regulate the expression of salicylic acid (SA)-related defense genes (CaPR1, CaPR10 and CaSAR8.2) as well as reactive oxygen species (ROS)-scavenging enzyme genes (CaCAT, CaPOD and CaSOD) in response to C. scovillei. In addition, CaWRKY20 was found to interact with CaMIEL1 in the nucleus to regulate the defense response to C. scovillei in pepper. Furthermore, CaWRKY20 directly bound to the W-box in the promoter of SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (CaSARD1) and suppressed its expression, resulting in reduced resistance to C. scovillei. These results will clarify the mechanism by which WRKY transcription factors are involved in pepper disease resistance and can thus facilitate molecular breeding for anthracnose-resistant varieties.

Chili pepper anthracnose, caused by Colletotrichum spp., is a significant biotic stress affecting chili fruits globally. While fungicide application is commonly used for disease management due to its efficiency and costeffectiveness, excessive use poses risks to human health and the environment. Botanical fungicides offer advantages such as rapid degradation and low toxicity to mammals, making them increasingly popular for sustainable plant disease control. This study investigated the antifungal properties of Cestrum tomentosum L.f. crude extracts (CTCE) against Colletotrichum scovillei. The results demonstrated that CTCE effectively inhibited conidia germination and germ tube elongation at 40 µg/ml concentrations. Moreover, CTCE exhibited strong antifungal activity against C. scovillei mycelial growth, with an EC50 value of 18.81 µg/ml. In vivo experiments confirmed the protective and curative effects of CTCE on chili pepper fruits infected with C. scovillei. XTT analysis showed that the CTCE could significantly inhibit the cell viability of C. scovillei. Mechanistic studies revealed that CTCE disrupted the plasma membrane integrity of C. scovillei and induced the accumulation of reactive oxygen species in hyphal cells. These findings highlight CTCE as a promising eco-friendly botanical fungicide for managing C. scovillei infections in chili peppers.

Colletotrichum species are notorious for causing anthracnose on many fruits, leading to significant economic losses worldwide. As a model, we functionally characterized cys2-his2 (C2H2) zinc finger proteins (CsCZFs) in Colletotrichum scovillei, a major causal agent of pepper fruit anthracnose in many countries. In all, 62 CsCZFs were identified by in silico genomic analysis. Twelve were selected based on their expression profiles to generate targeted deletion mutants for functional investigation. ΔCsczf1 markedly reduced conidiation and constitutive expression of CsCZF1 partially recovered conidiation in an asexual reproduction-defective mutant, ΔCshox2. Deletion of CsCZF12, orthologous to the calcineurin-responsive transcription factor Crz1, impaired autophagy in C. scovillei. ΔCsczf9 was defective in surface recognition, appressorium formation, and suppression of host defenses. CsCZF9 was identified as an essential and novel regulator under the control of the mitogen-activated protein kinase (CsPMK1) in an early step of appressorium development in C. scovillei. This study provides novel insights into CsCZF-mediated regulation of differentiation and pathogenicity in C. scovillei, contributing to understanding the regulatory mechanisms governing fruit anthracnose epidemics.IMPORTANCEThe phytopathogenic fungus Colletotrichum scovillei is known to cause serious anthracnose on chili pepper. However, the molecular mechanism underlying anthracnose caused by this fungus remains largely unknown. Here, we systematically analyzed the functional roles of cys2-his2 zinc finger proteins (CsCZFs) in the dissemination and pathogenic development of this fungus. Our results showed that CsCZF1 plays an important role in conidiation and constitutive expression of CsCZF1 restored conidiation in an asexual reproduction-defective mutant, ΔCshox2. The CsCZF9, a novel target of the mitogen-activated protein kinase (CsPMK1), is essential for surface recognition to allow appressorium formation and suppression of host defenses in C. scovillei. The CsCZF12, orthologous to the calcineurin-responsive transcription factor Crz1, is involved in the autophagy of C. scovillei. Our findings reveal a comprehensive mechanism underlying CsCZF-mediated regulation of differentiation and pathogenicity of C. scovillei, which contributes to the understanding of fruit anthracnose epidemics and the development of novel strategies for disease management.

Biocontrol potential of Bacillus velezensis HG-8-2 against postharvest anthracnose on chili pepper caused by Colletotrichum scovillei