Colletotrichum Lindemuthianum Research Articles

Alterations in Gene Expression during Incompatible Interaction between Amendoim Cavalo Common Bean and Colletotrichum lindemuthianum.

Anthracnose, caused by the fungus Colletotrichum lindemuthianum, poses a significant and widespread threat to the common bean crop. The use of plant genetic resistance has proven to be the most effective strategy for managing anthracnose disease. The Amendoim Cavalo (AC) Andean cultivar has resistance against multiple races of C. lindemuthianum, which is conferred by the Co-AC gene. Fine mapping of this resistance gene to common bean chromosome Pv01 enabled the identification of Phvul.001G244300, Phvul.001G244400, and Phvul.001G244500 candidate genes for further validation. In this study, the relative expression of Co-AC candidate genes was assessed, as well as other putative genes in the vicinity of this locus and known resistance genes, in the AC cultivar following inoculation with the race 73 of C. lindemuthianum. Gene expression analysis revealed significantly higher expression levels of Phvul.001G244500. Notably, Phvul.001G244500 encodes a putative Basic Helix-Loop-Helix transcription factor, suggesting its involvement in the regulation of defense responses. Furthermore, a significant modulation of the expression of defense-related genes PR1a, PR1b, and PR2 was observed in a time-course experiment. These findings contribute to the development of improved strategies for breeding anthracnose-resistant common bean cultivars, thereby mitigating the impact of this pathogen on crop yields and ensuring sustainable bean production.

Обзор върху антракнозата по фасула (Colletotrichum lindemuthianum) в Бъргария

Bean anthracnose, caused by Colletotrichum lindemuthianum, is a key disease in a number of countries around the world. Depending on the varietal structure and climatic conditions, yield losses vary from 10-58% to the complete destruction of crops. For the conditions of Bulgaria, the disease has a sporadic character in the plain areas, but in the mountainous areas it occurs annually. The pathogen control is related to uninfected seed material, long crop rotation, destruction of plant residues, application of fungicides and use of resistant varieties. C. lindemuthianum is characterized by considerable virulence diversity, which makes it difficult to breeding resistant cultivars and leads to overcoming already achieved resistance. This publication summarizes research on the virulence diversity of C. lindemuthianum in Bulgaria over the last forty years. In parallel, data on the resistance of Bulgarian dry bean varieties, some of which are essential for production in the country, to a set of physiological races of C. lindemuthianum are summarized. The analysis of the identified races shows significant virulence diversity in the pathogenic populations in Bulgaria. During the period 1979-2006, 10 physiological races were identified - 2, 3, 6, 22, 23, 54, 73, 79, 81 and 131. Race 81 was dominantly prevalent (78.4% of isolates) in traditional dry bean growing areas in the country. Races 2, 6, 22, 54 and 131 are established in the Rhodopе Mountains and Pirin Mountains. Races 3, 23, 73 and 79 were incidental to Bulgaria and there is no confirmation of their distribution. Of the 17 varieties presented in the overview, resistance to 11 races of C. lindemuthianum has variety Pukliv 1. Variety GTB Blyan is susceptible to races 6 and 81 and resistant to the remaining 9 physiological races included in the test. The Pirina variety is resistant to 10 of the 11 races tested. The varieties Pukliv 1, Trakya and Pirina are resistant to race 81, which prevails in Bulgaria. All cultivars have resistance to one or more of the investigated physiological races, which makes it possible to include them as resistance donors in the breeding of dry beans, by the pyramidal accumulation of race-specific genes.

Evaluation of Pinto Genotypes of Common Bean for Resistance to Anthracnose

ABSTRACTCommon bean (Phaseolus vulgaris L.) is an important crop grown for household revenue, food, and nutrition security in many parts of the world, especially in Africa and Latin America. Anthracnose caused by Colletotrichum lindemuthianum is a major disease of common bean globally. The objective of this study was to determine the response of selected pinto bean genotypes to seven races of C. lindemuthianum the causative fungus for anthracnose. A total of 56 pinto bean genotypes and three checks were evaluated for resistance to C. lindemuthianum races 51, 65, 73, 247, 253, 263, and 1085. Significant differences were observed among the 56 pinto genotypes in their reaction to the seven races, which was generally skewed towards susceptibility except for races 51 and 73. There was no genotype that was resistant to all seven races. In general, the genotypes that showed resistance to most of the races were those that carried Co‐42, which highlighted the importance of this locus to anthracnose resistance in pinto beans. Three genotypes—NDZ14006‐4, NDZ14110‐4, and NDZ14043—showed superior resistance (resistant to six of the seven races).

EFFECT OF CULTURE MEDIA ON GROWTH AND SPORULATION OF Colletotrichum lindemuthianum (SACC AND MAGN) ISOLATES CAUSING ANTHRACNOSE OF FIELD BEAN

Anthracnose (Colletotrichum lindemuthianum) is the most important fungal disease affecting field bean. Growth and sporulation of thirty six isolates of C. lindemuthianum collected from five agro-climatic zones of Andhra Pradesh was evaluated in the year 2017-18 on four different solid and liquid culture media. Results revealed that potato dextrose agar was the best for both radial growth (66.74 mm) and dry mycelial weight (264.74 mg), whereas, host leaf extract agar significantly supported more sporulation 7.3 x104. The least mycelia growth of 39.32 mm, dry mycelial weight of 234.70 mg and sporulation 2.9 x104 were observed on Sabourband’s agar. Among the different isolates, Cl-33 grew fast with mycelial growth and sporulation (78.86 mm and 8.4x104) and Cl-32 produced the highest dry mycelial weight 266.75 mg). The least radial growth (31.35 mm), the lowest sporulation (4.1 x104) and lowest mycelial dry weight (227.75 mg) was recorded in CI-28, CI-1 and CI 17, respectively. Mean conidial length of 36 isolates ranged from 11.87 to 13.03 µm with the maximum length (13.03 µm) recorded in host leaf extract agar, while minimum was recorded in oat meal agar. Width of conidia varied from 3.59 to 4.11 µm on different media and 3.53 to 4.23 µm in different isolates.The growth phase study revealed that increase in the dry mycelial weight of fungus upto 15 days of incubation and growth declined from 17th day onwards.

Selection of stable reference genes for qPCR expression of Colletotrichum lindemuthianum, the bean anthracnose pathogen

Phaseolus vulgaris L., commonly known as the common bean, is a highly nutritious crop often called the "poor man's meat”. However, it is susceptible to various diseases throughout the cropping season, with anthracnose caused by Colletotrichum lindemuthianum being a significant threat that leads to substantial losses. There is still a lack of understanding about the molecular basis of C. lindemuthianum pathogenicity. The first step in understanding this is to identify pathogenicity genes that express more during infection of common beans. A reverse transcription quantitative real-time PCR (qPCR) method can be used for virulence gene expression. However, this approach requires selecting appropriate reference genes to normalize relative gene expression data. Currently, there is no reference gene available for C. lindemuthianum. In this study, we selected eight candidate reference genes from the available genome of C. lindemuthianum to bridge the gap. These genes were ACT (Actin), β-tub (β-tubulin), EF (Elongation Factor), Cyt C (Cytochrome C), His H3 (Histone H3), CHS1 (Chitin synthetase), GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) and abfA (Alpha-l-Arabinofuranosidase A). The primers for these candidate reference genes were able to amplify cDNA only from the pathogen, demonstrating their specificity. The qPCR efficiency of the primers ranged from 80% to 103%. We analyzed the stability of gene expression in C. lindemuthianum by exposing the mycelium to nine different stress conditions. We employed algorithms, such as GeNorm, NormFinder, BestKeeper, and RefFinder tools, to identify the most stable gene. The analysis using these tools revealed that EF, GAPDH, and β-tub most stable genes, while ACT and CHS1 showed relatively low expression stability. A large number of potential effector genes have been identified through bioinformatics analysis in C. lindemuthianum. The stable genes for qPCR (EF and GAPDH) discovered in this study will aid the scientific community in determining the relative expression of C. lindemuthianum effector genes.

Characterization of phenotypic traits associated with anthracnose resistance in selected common bean (Phaseolus vulgaris L.) breeding material

Anthracnose caused by Colletotrichum lindemuthianum is the major common bean disease worldwide causing complete yield loss under favourable disease conditions. This study aimed to determine phenotypic traits associated with anthracnose resistance for future use in breeding programmes. Twenty-two common bean varieties (CBVs) were selected basing on susceptibility to anthracnose, advanced breeding lines, improved variety resembling advanced breeding lines and the farmer variety widely grown in Tanzania. Selected varieties were planted in anthracnose hotspot fields and the same CBVs were planted in a screen house to validate resistance to anthracnose. Anthracnose infection score, leaf length, leaf width, length of fifth internode, length of petiole, plant vigour, canopy height and canopy width were recorded. Data on number of plants emerging; days to flowering; days to maturity; plant stands at harvest; and grain yield were also collected and analysed using R software. Phenotypic traits evaluated differed significantly among genotypes, environment and genotype by environment interaction. Seventy-five percent of phenotypic traits evaluated were positively correlated to anthracnose resistance.Highly-strong correlations to anthracnose were observed on number of days to maturity, plant stands at harvest, plant vigour and grain yield. Leaf length, leaf width, length of fifth internode, length of petiole and number of stands emerging were strongly correlated to anthracnose resistance. Additive main effects and multiplicative interaction analysis (AMMI) revealed highest contribution of environment on anthracnose infection-58.9% and grain yield −84.9% compared to genotype effects on anthracnose infection −32.7% and grain yield-15.7%. Based on these results, four traits – plant vigour, number of days to maturity, number of plant stands at harvest and grain yield – are recommended for selecting anthracnose-resistant varieties. NUA 48, NUA 64 and RWR 2154 were superior varieties, resistant to anthracnose and high yielding, while Sweet Violet and VTT 923-23-10 were most stable varieties across environments. Further on-farm research is suggested to assess their performance and identify traits preferred by farmers.

Correction: Colletotrichum lindemuthianum race spectrum and resistant sources against most prevalent races in the North-western Himalayas: a three decade meta-analysis

Correction: Colletotrichum lindemuthianum race spectrum and resistant sources against most prevalent races in the North-western Himalayas: a three decade meta-analysis

The Pathogenicity Test, Cultural and Morphological Characterization of Anthracnose (Colletotrichum lindemuthianum) of Green Gram (Vigna radiata L. Wilczek)

Aims: The objective of this study was to identify the appropriate anthracnose fungus of green gram using symptomatology, identification, pathogenicity test and characterization of samples.
 Study Design:  Pathogenicity test, cultural and morphological characterization.
 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 during rabi 2020-21.
 Methodology: The sample was collected and subjected to isolation, purification and identification of pathogen. Four different pathogenecity tests were conducted to verify the pathogen causing anthracnose of green gram. On the other hand, the cultural and morphological characteristics of pathogen were studied. 
 Results: The pathogenecity test confirmed that the pathogen as Colletotrichum lindemuthianum in all four tests. Spraying inoculum after needle pricking and carborandum powder producing 100% infection in inoculated plants while 96% in spraying spore suspension without any abrasion. The less per cent of infection was observed in seed inoculated plants. The cultural studies of C. lindemuthianium shown sub-aerial whitish-to-pink cottony growth and pinkish-to-brown pigmentation under the culture plate. The morphological study of C. lindemuthianium observed as single-celled, hyaline, cylindrical, and smooth with oil globules. The acervuli were blackish brown and measure 181.3 × 254.6 µm. The setae were visible through the conidial mass with 1-3 septations.
 Conclusion: A study on green gram anthracnose confirmed C. lindemuthianum as pathogen in all four pathogenicity test with needle pricking and carborandum powder producing 100% infection in inoculated plants while 96% in spraying spore suspension without any abrasion. Cultural studies revealed whitish-pink cottony growth and pinkish-brown pigmentation. C. lindemuthianium was morphologically observed as single-celled, hyaline, cylindrical, smooth, with oil globules, blackish brown acervuli, and visible setae through conidial mass with 1-3 septations. Therefore, these findings are important for identifying the anthracnose disease of green gram.

Colletotrichum lindemuthianum race spectrum and resistant sources against most prevalent races in the North-western Himalayas: A three decade meta-analysis

Colletotrichum lindemuthianum race spectrum and resistant sources against most prevalent races in the North-western Himalayas: A three decade meta-analysis

Diseases prevalent in Kharif crops grown in Barmer district of Rajasthan, India

In the Kharif season, pearl millet (Pennisetum glaucum) is the predominant crop of the Barmer district followed by cluster bean (Cyamopsis tetragonoloba) and moth bean (Vigna aconitifolia). Sesame (Sesamum indicum) and green gram (Vigna radiata) are other important Kharif oilseed and pulse crops, respectively. A survey was conducted to determine the status of major diseases of Kharif crops grown in the Barmer district of the Marwar region of Rajasthan, India. Five blocks and three villages in each block were surveyed through a random field survey method during the collection of diseased samples every Sunday for the practical classes of agricultural students of the College of Agriculture, Baytu; in August and September 2023. Per cent disease incidence was recorded on randomly selected plants in a particular field of selected location. The incidence of diseases was observed based on typical field symptoms and later the association was confirmed through microscopic examinations in the laboratory. In survey, yellow mosaic (virus), leaf crinkle/ curl (virus), bacterial leaf spot/ blight (Xanthomonas phaseoli) of green gram;green ear/ downy mildew (Sclerospora graminicola), rust (Puccinia substriata) and blast (Pyricularia grisea) of pearl millet; Phytophthora stem blight (Phytophthora parasitica var. sesame) and phyllody (Phytoplasma) of sesame; yellow mosaic (virus)and bacterial leaf spot/ blight (Xanthomonas axonopodis pv. cyamopsidis) of cluster beanwere recorded with >50% incidence. However; charcoal rot (Macrophomina phaseolina), web blight (Rhizoctonia solani), Cercospora leaf spot (Cercospora canescens) and anthracnose (Colletotrichum lindemuthianum) of green gram; Alternaria blight/ leaf spot (Alternaria sesame) of sesame,sorghum rust (Puccinia purpurea) and Alternaria blight/ leaf spot (Alternaria cyamopsidis) of cluster beanwere noticed with 10 to 50% incidence.

Morphological and transcriptional analysis of Colletotrichum lindemuthianum race 7 during early stages of infection in common bean.

The infection process of the hemibiotrophic fungus Colletotrichum lindemuthianum has been independently studied at the microscopic and genomic levels. However, the relationship between the morphological changes and the pathogenicity mechanisms of the fungus at the early stages of the infection remains uncharacterized. Therefore, this study attempts to bridge this gap by integrating microscopic and transcriptional approaches to understand the infection process of C. lindemuthianum. Fungal structures were followed by fluorescence microscopy for 120 hours. Simultaneously, the transcriptomic profile was made using RNAseq. Morphological characterization shows that appressoria, infective vesicles, and secondary hypha formation occur before 72 hours. Additionally, we assembled 38,206 transcripts with lengths between 201 and 3,548 bp. The secretome annotation revealed the expression of 1,204 CAZymes, of which 17 exhibited secretion domains and were identified as chitinases and β-1,3-glucanases, 27 were effector candidates, and 30 were transport proteins mostly associated with ABC-type. Finally, we confirmed the presence and expression of CAC1 role during the appressoria formation of Clr7. This result represents the first report of adenylate cyclase expression evaluated under three different approaches. In conclusion, C. lindemuthianum colonizes the host through different infection structures complemented with the expression of multiple enzymes, where CAC1 favors disease development.

Fine mapping of a new common bean anthracnose resistance gene (Co-18) to the proximal end of Pv10 in Indian landrace KRC-5.

Mapping and fine mapping of bean anthracnose resistance genes is a continuous process. We report fine mapping of anthracnose resistance gene Co-18 which is the first anthracnose gene mapped to Pv10. The discovery of resistance gene is a major gain in the bean anthracnose pathosystem research. Among the Indian common bean landraces, KRC-5 exhibit high levels of resistance to the bean anthracnose pathogen Colletotrichum lindemuthianum. To precisely map the anthracnose resistance gene, we used a Recombinant Inbred Line (F2:9 RIL) population (KRC-5 × Jawala). The inheritance test revealed that KRC-5 carries a dominant resistance gene temporarily designated as Co-18. We discovered two RAPD markers linked to Co-18 among 287 RAPD markers. These RAPD markers were eventually developed into SCARs (Sc-OPR15 and Sc-OPF6) and flank Co-18 on chromosome Pv10 at a distance of 5.3 and 4.2cM, respectively. At 4.0-4.1Mb on Pv10, we detected a SNP (single-nucleotide polymorphism) signal. We synthesized 58 SSRs and 83 InDels from a pool of 135 SSRs and 1134 InDels, respectively. Five SSRs, four InDels, and two SCARs were used to generate the high-density linkage map, which led to the identification of two SSRs (SSR24 and SSR36) that are tightly linked to Co-18. These two SSRs flank the Co-18 to 178kb genomic region with 13 candidate genes including five NLR (nucleotide-binding and leucine-rich repeat) genes. The closely linked markers SSR24 and SSR36 will be used in cloning and pyramiding of the Co-18 gene with other R genes to develop durable resistant bean varieties.

Pathogenically altered Colletotrichum lindemuthianum transformants help in understanding the biochemical defense and colonization dynamics in Phaseolus vulgaris

Colletotrichum lindemuthianum poses a serious threat to common bean production and impacts food security. It is essential to comprehend the intricate nature of the pathogen infection process and the underlying biochemical systems regulating plant defence to create tactics that effectively increase plant resistance. This study leveraged a stable C. lindemuthianum transformant library to examine these intrinsic mechanisms in a susceptible Phaseolus vulgaris cultivar, Jawala. Among the 57 mitotically stable transformants employed to screen for altered virulence, 51 were pathogenically similar to wild type and the remaining six transformants were either reduced or impaired. Nine transformants (three pathogenically similar and all impaired and reduced mutants) were selected for subsequent studies. These mutants exhibited an array of morpho-cultural variations. The biochemical studies of these mutants revealed free radicals as double-edged swords, exerting a pivotal influence on the infection process. The free radical (H2O2) elevated at an early stage (24 hpi) in the cases of reduced (CT-51) and impaired (CT-225) mutants. However, at the later stage (72 hpi), H2O2 was promoted in the case of R-2047 and equal to wild type (CT-101) transformant. Contrary, superoxide (O2−) increased considerably at 48 hpi in the incompatible interaction of reduced (CT-51) and impaired (CT-225) mutants. The microscopic images revealed how easily the wild type (CT-101) could germinate, penetrate, and infect the leaves. The pathogenically reduced transformant (CT-51), however, had delayed germination as well as a decreased growth rate and spore production. Additionally, the pathogenicity of the impaired transformant (CT-225) was completely lost, and its conidia failed to properly germinate. This is the first account of C. lindemuthianum in planta colonization with a GFP tag. This study increased our understanding of the mechanics of the reactions triggered by C. lindemuthianum and may be used to develop novel strategies for the effective control of bean anthracnose. Additionally, identifying the genes disrupted by the insertion of Agrobacterium T-DNA will help in identifying the genes necessary for bean plant colonization.

Response of Biofortified Green Bean Plants to Colletotrichum lindemuthianum

Enhancing crop nutrition though biofortification with essential minerals can, in some circumstances, increase the resistance of plants to the attack by pathogens. As a result, plants activate their defense mechanisms and produce bioactive compounds (BCs) in response. To date, there has been no investigation into the response of green bean plants fortified with magnesium (Mg) salts to the presence of Colletotrichum lindemuthianum. This research involved two Mg sources applied by the edaphic route. The pathogen was inoculated on green bean pods, and subsequent analysis was conducted on the accumulation of BCs, including total anthocyanins, total phenols, and total flavonoids, within both symptomatic and healthy tissues. Remarkably, the plant’s defense system was activated, as evidenced by the significantly higher concentration of anthocyanins (p ≤ 0.05) observed in the symptomatic tissues following treatments with both MgCl2 and MgSO4. Further, green bean plants treated with MgSO4 displayed notably elevated concentrations of phenols (p ≤ 0.05) in the inoculated tissues of the pods, suggesting a plausible plant defense mechanism. The levels of BCs were considerably higher in green bean pods of the biofortified plants compared to those which were nonbiofortified. However, perhaps one of the most noteworthy findings is that there were no discernible differences between biofortified and nonbiofortified treatments in stopping anthracnose in green bean pods. These results provide valuable insights contributing to a deeper understanding of this interaction.

Comprehensive biochemical approach forunderstanding the interaction between host "common bean" and pathogen "Colletotrichum lindemuthianum" causing bean anthracnose.

Anthracnose (ANT) caused by Colletotrichum lindemuthianum is the most devastating seed-borne fungal disease of common bean. In response to fungal infections, it is hypothesized that pathogen-plant interactions typically cause hypersensitive reactions by producing reactive oxygen species, hydrogen peroxide and lipid peroxidation of cell membranes. esent study was conducted by inoculating susceptible bean genotype "SB174" and resistant bean genotype "E10" with pathogen "C. lindemuthianum". Defense-related enzymes (ascorbate peroxidase, peroxidase, lipid peroxidase, and catalase) and C-based compounds (total phenols and flavonoids) were studied using the detached bean leaf method. Comparative defense response was studied in different plant tissues (pod, stem, and seed) in susceptible and resistant bean genotypes under uninoculated and pathogen-inoculated conditions. The host‒pathogen interaction was studied at mock inoculation, 2, 4 and 6 days after inoculation (dai). Comparing the pathogen-inoculated bean leaves to water-treated bean leaves, defense enzymes as well as total phenols and flavonoids exhibited differential expression. In a comparative study, the enzyme activity also displayed differential biochemical responses in pods, stems and seeds in both contrasting genotypes. For example, 5.1-fold (pod), 1.5-fold (stem) and 1.06-fold (seed) increases in ascorbate peroxidase activity were observed in the susceptible genotype at 6 dai compared to mock inoculation. Similarly, catalase activity in pods was upregulated (1.47-fold) in the resistant genotype and downregulated (1.30-fold) in the susceptible genotype at 6 dai. The study revealed that defense-related antioxidative enzymes, phenols and flavonoids are fine-tuned to detoxify important reactive oxygen species (ROS) molecules, induce systemic resistance and are successfully controlled in common bean plants against pathogen invasion.

Potential Endophytic Fungi from the Leaves of Syzygium zeylanicum (L.) and Their Secondary Metabolite

Endophytic fungi coexist without harms in the host in some parts or all parts of its lifecycle. Endophytic fungi excrete specialized bioactive compounds beneficial for of its host; the compound itself can be different from what can be found on their host. Endophytic fungi are capable to excrete biologically significant secondary metabolites acting as antidiabetic, antioxidant, antimicrobial, and cytostatic agents. Endophytic fungi existence are common across different plants; including Syzygium zeylanicum that can be found in Indonesia. This study aims to isolate endophytic fungi found in leaves of Syzygium zeylanicum, L., to elucidate their characterized morphologically, and to examine its antimicrobial and antioxidant properties in addition to their chemical structures. Characterization of endophytic fungi was conducted by their macroscopic and microscopic features, followed by molecular characterization of highly bioactive metabolites. Antimicrobial activities were measured by disc diffusion method. Antioxidant properties were measured with DPPH. Secondary metabolites were chromatographically isolated and identified with spectroscopy techniques (NMR ID and 2D). Four endophytic fungi isolates were obtained: Penicillium citrinum (SZ1), Colletotrichum lindemuthianum (SZ2), Aspergillus nidulan (SZ3), Scopulariopsis asperula (SZ4). Penicillium citrinum (SZ1) showed antimicrobial activities against four different bacteria (71.3% against E. coli; 74.1% against S. aureus; 76.2% against S. typhi; and dan76.9% against B. subtilis). Antioxidant activity ini all ekstrak of endophytic fungi showed very activity (IC50 SZ3 extract = 3.85 µg/mL). Potential endophytic fungi SZ1 was molecularly identified as Penicillium citrinum. Extracts from SZ1 fungi contains bioactive 4-hydroxy-2-(4-hydroxyphenyl)-ɣ-butyrolactone-3-yl) methyl acetate. The newly obtained substance could be developed into antimicrobial and antioxidant agents in further studies.

Genome-wide association analysis of anthracnose resistance in the Yellow Bean Collection of Common Bean

Anthracnose caused by Colletotrichum lindemuthianum is a major disease of common bean (Phaseolus vulgaris) worldwide. Yellow beans are a major market class of common bean especially in eastern and southern Africa. The Yellow Bean Collection (YBC), which is comprised of 255 genotypes, and has not been used previously in genetic studies on anthracnose, is an excellent genetic resource for understanding the extent of anthracnose resistance and its genetic architecture in the yellow bean market class. The objectives of this study were i) evaluate the YBC for resistance to races 5, 19, 39, 51, 81, 183, 1050 and 1105 of C. lindemuthianum. and ii) conduct genome-wide association analysis to identify genomic regions and candidate genes associated with resistance to C. lindemuthianum. The YBC was genotyped with 72,866 SNPs, and genome-wide association analysis was conducted using Mixed Linear Model in TASSEL. Andean and Middle American genotypes with superior levels of resistance to the eight races were identified. YBC278 was the only one among 255 genotypes that was highly resistant to all eight races. Resistance to anthracnose in the YBC was controlled by major-effect loci on chromosomes Pv01, Pv03, Pv04, Pv05 and Pv07. The genomic region on Pv01, which overlapped with the Andean locus Co-1 provided resistance to races 81, 1050 and 1105. Significant SNPs for resistance to race 39 were identified on Pv02. The genomic region on Pv04, which overlapped with known major-effect loci Co-3, Co-15, Co-16, Co-y and Co-z, provided resistance to races 5, 19, 51 and 183. Novel genomic regions for resistance to race 39 were identified on Pv05 and Pv07. Plant resistance genes (R genes) with NB-ARC and LRR domains, which occurred in clusters, were identified as positional candidate genes for genomic regions on Pv02 and Pv04.

Responsiveness of Candidate Genes on CoPv01CDRK/PhgPv01CDRK Loci in Common Bean Challenged by Anthracnose and Angular Leaf Spot Pathogens.

Anthracnose (ANT) and angular leaf spot (ALS) are significant diseases in common bean, leading to considerable yield losses under specific environmental conditions. The California Dark Red Kidney (CDRK) bean cultivar is known for its resistance to multiple races of both pathogens. Previous studies have identified the CoPv01CDRK/PhgPv01CDRK resistance loci on chromosome Pv01. Here, we evaluated the expression levels of ten candidate genes near the CoPv01CDRK/PhgPv01CDRK loci and plant defense genes using quantitative real-time PCR in CDRK cultivar inoculated with races 73 of Colletotrichum lindemuthianum and 63-39 of Pseudocercospora griseola. Gene expression analysis revealed that the Phvul.001G246300 gene exhibited the most elevated levels, showing remarkable 7.8-fold and 8.5-fold increases for ANT and ALS, respectively. The Phvul.001G246300 gene encodes an abscisic acid (ABA) receptor with pyrabactin resistance, PYR1-like (PYL) protein, which plays a central role in the crosstalk between ABA and jasmonic acid responses. Interestingly, our results also showed that the other defense genes were initially activated. These findings provide critical insights into the molecular mechanisms underlying plant defense against these diseases and could contribute to the development of more effective disease management strategies in the future.

Antifungal activities of leaf extracts from the Capsicum genus

The emergence of microorganisms resistant to antimicrobials has driven the search for new substances aimed at the control and prevention of pathogens. Plant antimicrobial peptides have biotechnological applications in the development of drugs and agricultural inputs for this purpose. The present work aims to evaluate the antifungal activity of extracts containing peptides obtained from the leaves of Capsicum plants. The accessions UENF 1626, 1632 and 1381 and the cultivar Carioquinha were used. The leaves were macerated, and then extraction was performed using a 60% methanol and dichloromethane solution in a 1:1 ratio. The hydromethanolic phase was separated and used for testing after evaporation of methanol. All extracts have a similar electrophoretic profile on tricine gel stained with Coomassie Blue, showing 2 bands of approximately 6.5 and 3.5 kDa. Inhibition of fungal growth with 24 h of culture was performed in liquid culture medium in 96-well plates with reading at 620 nm using extracts with a protein concentration of 200 mg mL-1. The filamentous fungi Fusarium solani, Fusarium lateritium, and Colletotrichum lindemuthianum and the yeasts Candida albicans, Candida buinensis, Candida tropicalis, Saccharomyces cerevisiae, Pichia membranifaciens and Kluyveromyces marxianus were used. The extract with the greatest antifungal potential was the leaves of Capsicum annuum cv. Carioquinha, inhibiting the growth of F. solani by 29%, C. lindemuthianum by 15%, Candida buinensis by 22% and K. marxianus by 24%. Therefore, the extract has peptides with biotechnological potential.

Automating high-throughput screening for anthracnose resistance in common bean using allele specific PCR

BackgroundCommon beans (Phaseolus vulgaris L.) provide important protein and calories globally. Anthracnose (Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara, 1889) is a major disease in common bean and causes significant yield losses in bean production areas. Screening for markers linked to known disease resistance genes provides useful information for plant breeders to develop improved common bean varieties. The Kompetitive Allele Specific PCR (KASP) assay is an affordable genetic screening technique that can be used to accelerate breeding programs, but manual DNA extraction and KASP assay preparation are time-consuming. Several KASP markers have been developed for genes involved in resistance to bean anthracnose, which can reduce yield by up to 100%, but their usefulness is hindered by the labor required to screen a significant number of bean lines. Our research objective was to develop publicly available protocols for DNA extraction and KASP assaying using a liquid handling robot (LHR) which would facilitate high-throughput genetic screening with less active human time required. Anthracnose resistance markers were used to compare manual and automated results.ResultsThe 12 bean anthracnose differential cultivars were screened for four anthracnose KASP markers linked to the resistance genes Co-1, Co-3 and Co-42 both by hand and with the use of an LHR. A protocol was written for DNA extraction and KASP assay thermocycling to implement the LHR. The LHR protocol reduced the active human screening time of 24 samples from 3h44 to 1h23. KASP calls were consistent across replicates but not always accurate for their known linked resistance genes, suggesting more specific markers still need to be developed. Using an LHR, information from KASP assays can be accumulated with little active human time.ConclusionResults suggest that LHRs can be used to expedite time-consuming and tedious lab work such as DNA extraction or PCR plate filling. Notably, LHRs can be used to prepare KASP assays for large sample sizes, facilitating higher throughput use of genetic marker screening tools.