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Colletotrichum truncatum isolate 6.1MM. (A) Setose stroma. (B) Conidiogenous cell in sporodochia immersed in the stroma. (C) Falcate conidia (D-G) Shapes of appressoria.
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Brazil and Argentina have a combined soybean area of 53.6 million hectares, which accounts for over half of the total global production. The soybean crop in South America extends from latitude 8-10 • S to 32-36 • S. Such a vast, almost contiguous area imposes a serious sanitary risk to the crop. Currently, the prevalence of anthracnose is increasin...
Citations
... Soybean anthracnose is classified as a disease of complex etiology (Dias et al. 2018) and to date, six Colletotrichum species complex (C. dematium, C. magnum, C. gloeosporioides, C. orchidearum, C. truncatum, and C. chlorophyti) have been confirmed to be pathogenic to soybean (Boufleur et al. 2021), with C. truncatum being the most prevalent species associated with anthracnose (Sharma et al. 2011;Yang and Hartman 2015;Dias et al. 2019;Boufleur et al. 2021). In Brazil, the most recent research on anthracnose focuses on C. truncatum, but with limited information about other Colletotrichum species that also affect soybeans (Boufleur et al. 2021). ...
Anthracnose disease caused by Colletotrichum species has resulted in increased economic losses on soybean fields in Brazil. For the disease management, fungicide is the main disease control strategy used. Recently, variations in field performance of fungicides on anthracnose have been observed and were speculated to be a result of distinct Colletotrichum species occurring in the fields. Therefore, this study aimed to identify the species occurring in the sampled soybean fields and evaluate the sensitivity of 30 Colletotrichum samples collected from 2021 and 2022 seasons to benzovindiflupyr (BVF), fluxapyroxad (FXD), inpyrfluxam (IPFX), difenoconazole (DFZ), prothioconazole (PTZ) and mefentrifluconazole (MFTZ). Twenty-three samples were identified as C. plurivorum and seven samples were identified as C. truncatum based on molecular analysis. The SDHI fungicide BVF, and DMIs DFZ and PTZ, showed higher fungitoxicity against C. plurivorum and C. truncatum than the other fungicides tested. BVF showed the same intrinsic activity on both C. plurivorum and C. truncatum. To our knowledge , this is the first study reporting the sensitivity of Colletotrichum species to six fungicides and showed the C. plurivorum and C. truncatum tested samples were more sensitive to BVF, PTZ, and DFZ than to FXD, IPFX, and MFTZ. These results add important information for anthracnose and anti-resistance management on soybean using SDHI and DMIs fungicides.
... The anthracnose severity of mungbean and blackgram in India increased with an increase in temperature and relative humidity whereas rainfall had little effect (Kulkarni, 2019;Gupta, 2021;Pandey et al., 2021a). Likewise, increased soybean anthracnose severity was related to an increase in temperature and relative humidity in India (Nataraj et al., 2020), Brazil (J unior et al., 2021), and Argentina (Dias et al., 2019). Similarly, elevated temperature and relative humidity significantly reduced lentil production in Canada (Buchwaldt et al., 2018), common bean production in Africa (Mukankusi et al., 2019), and cowpea production in Nigeria (Falade and Borisade, 2018), in each case a consequence of increased anthracnose severity. ...
... Few studies have been undertaken to identify sources of resistance to soybean. By inoculating 16 soybean accessions with C. truncatum isolates in Brazil, Dias et al. (2019) found that while some soybean accessions had a high level of resistance in stems these same lines were highly susceptible to cotyledon infection. They hypothesized that stems and cotyledons likely had distinctly different genetic resistances with independent mechanisms of resistance. ...
... They hypothesized that stems and cotyledons likely had distinctly different genetic resistances with independent mechanisms of resistance. While different searches for sources of resistance in soybean against C. truncatum have been conducted (Costa et al., 2009;Nagaraj et al., 2014;Dias et al., 2019), there has been no research to date on sources of resistance against other Colletotrichum species associated with soybean anthracnose. In contrast, many studies have been carried out to identify race specific sources of anthracnose resistance in common bean worldwide (Table 2). ...
Anthracnose, caused by hemibiotrophic Colletotrichum spp., is a destructive disease of legumes and many other crops worldwide. Colletotrichum spp. constitute one of the top 10 phytopathogenic fungi, infecting ~3,000 plant species, attacking food and forage legume crops at all growth stages; including seed, seedlings, young, and mature plants; with consequent significant yield reductions. Presently, cultural practices and substantial use of synthetic fungicides are the most prevalent approaches for anthracnose management. In addition, there has been a strong focus towards developing advanced breeding lines and cultivars with improved anthracnose resistance. This has involved traditional breeding resulting in a wide range of anthracnose resistance resources being identified, particularly using advanced techniques within common bean, soybean, lentil, mungbean, blackgram, and lupins. For instance, quantitative trait loci (QTLs) for resistance have been identified, enabling marker-assisted resistance breeding. More recently, molecular approaches; including genomics, transcriptomics, proteomics, and metabolomics; have been utilized to understand the pathogenesis and defense mechanisms involved in the Colletotrichum-legume interaction. Genetic manipulation through omics offers scope to better protect legumes from anthracnose by improving the efficiency of breeding programs. This review focuses on key pathogens (viz., C. truncatum, C. lentis, C. lupini, and C. lindemuthianum) causing anthracnose in legumes, their biology and epidemiology, the disease management levers embracing progress with host resistance, genetic and breeding approaches, and highlights critical knowledge gaps in conventional and molecular breeding programs. We conclude that the ongoing progress toward developing breeding lines/cultivars/donors with improved resistance in legume plant responses against anthracnose using omics approaches offers novel insights into legume-anthracnose pathogen interactions and ensures more sustainable and effective disease management strategies for the future.
... Bacillus subtilis, Bacillus megaterium and Escherichia coli were used as common laboratory strains. Colletotrichum truncatum, which is responsible for the dangerous soybean anthracnose in Argentina causing significant yield losses [66], is the only fungus used. The results obtained showed that the antibacterial and antifungal activity of lipodepsipeptides in the inhibition of microbial growth was 56-60 times higher than that of dicylopeptides. ...
... Thus, the dideacetyl derivative of FC, which is obtained by easy hydrolysis of the toxin (209) and could be prepared in high yield, had a potential for its practical application as a stimulant of P. ramosa to its biocontrol based on "suicidal germination" [238]. Successively, considering these results and the structural relation between FC-A (209) and ophiobolin A (66) and that the stimulation of seed germination is species-dependent, the two toxins and seven of the above cited FC derivatives were assayed at the concentration range of 10 −4 -10 −7 M on seed germination of different Orobanche species such as P. aegyptiaca, P. ramosa, O. crenata, O. cumana, O. densiflora, O. fetida, O. gracilis, O. hederae and O. minor. Among all the compound tested, ophiobolin A and the hexacetyl and pentacetyl isomers of 16-O-demethyl-de-t-pentenylfusicoccin showed the highest stimulatory effect, while the other fusicoccin derivatives appeared to be practically inactive. ...
Weeds such as parasite plants are one of the most serious pests that farmers are forced to combat since the development of agriculture using different methods including mechanic and agronomy strategies. These pests have generated significant losses of agrarian and herding production, constituting a serious impediment for agricultural activities in reforestation practices and in important infrastructures. All these serious problems have induced the expansive and massive use of synthetic herbicides, which represents one of the main cause of environmental pollution, as well as serious risks for human and animal health. An alternative environmental friendly control method could be the use of bioherbicides based on suitably bioformulated natural products, of which the main ones are fungal phytotoxins. This review covers the literature from 1980 to the present (2022) and concerns fungal phytotoxins with potential herbicidal activity in order to obtain their efficacy as bioherbicides for practical application in agriculture. Furthermore, some bioherbicides based on microbial toxic metabolites are commercially available, and their application in field, mode of action and future perspectives are also discussed.
... Introduction and soybean (Stommel and Haynes, 1998;Prochno et al., 2016;Dias et al., 2019;Jacobs et al., 2019). Plant pathogens in both the field and post-harvest, Colletotrichum spp. ...
Anthracnose is a widespread plant disease caused by various species of the fungal pathogen Colletotrichum spp. In solanaceous plants such as tomato (Solanum lycopersicum), Colletotrichum infections exhibit a quiescent, asymptomatic state in developing fruit, followed by a transition to necrotrophic infections in ripe fruit. Through analysis of fruit tissue extracts of 95L368, a tomato breeding line that yields fruit with enhanced anthracnose resistance, we identified a role for steroidal glycoalkaloids (SGAs) in anthracnose resistance. The SGA α-tomatine and several of its derivatives accumulated at higher levels, in comparison to fruit of the susceptible tomato cultivar US28, 95L368 fruit extracts with fungistatic activity against Colletotrichum. Correspondingly, ripe and unripe 95L368 fruit displayed enhanced expression of glycoalkaloid metabolic enzyme (GAME) genes, which encode key enzymes in SGA biosynthesis. Metabolomics analysis incorporating recombinant inbred lines (RILs) generated from 95L368 and US28 yielded strong positive correlations between anthracnose resistance and accumulation of α-tomatine and several derivatives. Lastly, transient silencing of expression of the GAME genes GAME31 and GAME5 in anthracnose-susceptible tomato fruit yielded enhancements to anthracnose resistance. Together, our data support a role for SGAs in anthracnose defense in tomato, with a distinct SGA metabolomic profile conferring resistance to virulent Colletotrichum infections in ripe fruit.
... Limited number and variability of morphological characters is directly related to the difficulty in delimiting species of Colletotrichum Hyde et al. 2009;Sutton 1992). C. truncatum isolates collected in Brazil and Argentina were characterised based onmolecular, morphological, biological, cultural, and pathogenicity testby Dias et al. (2019). Conglomerate closely related species were identified using overlapping morphology (conidial and colony characteristics) which resulted in exploiting molecular tools for species identification Cannon et al. 2012;He et al. 2016).Therefore, molecular techniques and phylogenetic studies were carried out with all the 28 isolates. ...
... Lack of sexual teleomorph may be the reason for close identity among C. truncatum isolates. Similar conference has been independently derived by Rogério et al. (2019) and Dias et al. (2019).The description of one new species from this work, illustrate the need for careful molecular analyses to help establish species boundaries in Colletotrichum. Future work should aim at exhaustive sampling using an unexplored population approach followed by use of more advanced molecular techniques based on single nucleotide polymorphism and next generation sequencing for taxonomic identification of Colletotrichum. ...
IntroductionSoybean is a globally grown oilseed and pulse crop with India occupying fourth position in soybean production. Pod blight disease in soybean is caused by broad-range pathogens Colletotrichum spp. which are not limited by their host range.Objectives
Colletotrichum population from soybean growing districts of Chhattisgarh was analysed using polyphasic morphological & molecular approach.Methods
Due to similar morphology of most of the Colletotrichum isolates, species identity could not be resolved morphologically. Therefore PCR based sequencing was done.ResultsTypical conidial morphology of C. Truncatum was observed with all the isolates except two isolates C27 & C28. ITS sequencing approach identified twenty three isolates as Colletotrichum truncatum. Species identity could not be delineated to one of the Colletotrichum isolate C19. Chromosomal 18S-28S rRNA intervening DNA sequences analysis of two isolates C27 and C28 derived from naturally infected pods resolved similarity of these isolates with Paraconiothyrium fuscomaculans (EU754197) and Westerdykella capitulum (GU238054) respectively. Intervening DNA sequences of both occupied sister position in cladogram containing several distantly related species of Colletotrichum.Conclusion
Present study on Colletotrichum taxonomy is important in minimizing risk exposure and the likelihood of an incident of disease to the soybean growing areas of Chhattisgarh.
... By openly sharing its full methodology and the blueprints of the trans-illuminator we foresee its adoption throughout the country as a phenotyping platform for monitoring the fungicide resistance status of populations of several other important necrotrophic or hemibiotrophic fungal plant pathogens, besides M. fijiensis, M. musicola, and P. oryzae. In Brazil, these relevant pathogens include, as examples, Alternaria alternata on tangerines [43], Botrytis cinerea on strawberries [44], Colletotrichum accutatum on apples [45], Colletotrichum truncatum and Corynespora cassiicola on soybeans [46][47][48], Lasiodiplodia theobromae on papaya [49], Monilinia fruticola on stone fruits [50], Phyllosticta citricarpa on citrus [51], and Ramulariopsis gossypii and R. pseudoglycines on cotton [52]. This fungicide resistance phenotyping platform will certainly require successful optimization and validation of the COL-assay for such a broad range of pathosystems. ...
This study aimed at the development and validation of an accurate, more affordable, and precise digital imaging resazurin-based fungicide sensitivity colorimetric assay (COL-assay) for fungal plant pathogens from the genera Mycosphaerella and Pyricularia. This proposed digital imaging assay was based on colorimetric estimates of resazurin reduction, which was used as a metabolic indicator of fungal respiration activity on microplate cultures. As fungal model systems, we used the yellow and black Sigatoka pathogens [Mycosphaerella musicola (Mm) and M. fijiensis (Mf), respectively] and the wheat blast pathogen, Pyricularia oryzae Triticum lineage (PoTl), which were previously characterized for QoI, DMI, and SDHI fungicide sensitivity. We then compared the classical spectrophotometry detection assay (SPEC-assay) with the proposed COL-assay based on the analyses of digital images of the microplates’ cultures captured with mobile phone cameras on a handmade trans-illuminator built for poorly equipped labs. Qualitatively, in terms of accuracy, there was full correspondence between the SPEC-assay and the COL-assay according to the fungal EC50 or the relative growth classes on QoI, SDHI, and DMI fungicides for both Mycosphaerella and Pyricularia pathogens. We also observed a strong to very strong correlation coefficient between the COL-assay and the SPEC-assay fungicide sensitivity values for the QoI azoxystrobin, the SDHI fluxapyroxad, and the DMI tebuconazole. Our conclusion was that the COL-assay had a similar accuracy as the SPEC-assay (i.e., resulted in similar fungicide-sensitivity categories for both resistant or sensitive fungal isolates) and high precision. By openly sharing here the COL-assay’s full methodology, and the blueprints of the handmade trans-illuminator, we foresee its adoption by poorly equipped labs throughout the country as an affordable venue for monitoring the fungicide resistance status of populations of important fungal plant pathogens such as M. fijiensis, M. musicola, and P. oryzae Triticum and Oryza lineages.
... Anthracnose is a global plant disease caused by Colletotrichum spp., hemibiotrophic fungal pathogens with a wide and diverse host range, including a variety of commercially important monocot and 55 dicot crops such as tomato, maize, strawberry, and soybean (Dias et al., 2019;Jacobs et al., 2019;Prochno 3 infections of tomato fruit exhibit a transition from quiescence to virulence during fruit ripening, yielding anthracnose symptoms on ripe fruit. After overwintering in soil, sclerotia form conidia capable of germinating on immature fruit, resulting in an asymptomatic, quiescent state characterized by the formation of appressoria that are restricted to the cuticle. ...
Anthracnose is a widespread plant disease caused by various species of the fungal pathogen Colletotrichum. In solanaceous plants such as tomato (Solanum lycoperiscum), Colletotrichum infections exhibit a quiescent, asymptomatic state in developing fruit, followed by a transition to necrotrophic infections in ripe fruit. Through analysis of fruit tissue extracts of 95L368, a tomato breeding line that yields fruit with enhanced anthracnose resistance, we identified a role for steroidal glycoalkaloids (SGAs) in anthracnose resistance. The SGA α-tomatine and several of its derivatives accumulated at higher levels, in comparison to fruit of the susceptible tomato cultivar US28, in 95L368 fruit extracts with fungistatic activity against Colletotrichum. Correspondingly, ripe and unripe 95L368 fruit displayed enhanced expression of glycoalkaloid metabolic enzyme (GAME) genes, which encode key enzymes in SGA biosynthesis. Metabolomics analysis incorporating recombinant inbred lines (RILs) generated from 95L368 and US28 yielded strong positive correlations between anthracnose resistance and accumulation of α-tomatine and several derivatives. Lastly, transient silencing of expression of the GAME genes GAME31 and GAME5 in anthracnose-susceptible tomato fruit yielded enhancements to anthracnose resistance. Together, our data support a role for SGAs in anthracnose defense in tomato, with a distinct SGA metabolomic profile conferring resistance to virulent Colletotrichum infections in ripe fruit.
Highlight
This work describes an important role for steroidal glycoalkaloids (SGAs), abundant secondary metabolites in tomato fruit, in defense against anthracnose, a widespread fungal disease that impacts diverse crop species.
... Aboveground organs of soybean plants, including the cotyledons, stems, pods, petioles, veins, and leaves can be infected at any stage of development by C. truncatum . Infection severely affects soybean growth and development (Rogério et al., 2017;Tian et al., 2017;Dias et al., 2019). Anthracnose infection is favored by high temperature and moisture. ...
... Anthracnose infection is favored by high temperature and moisture. Hence, this disease causes significant losses in soybean crops in subtropical and tropical regions, including the southern soybean-growing areas of China and the United States, as well as northern Argentina, Brazil, Thailand, and India (Wrather et al., 2010;Mahmodi et al., 2013;Dias et al., 2016Dias et al., , 2019Nataraj et al., 2020). ...
Anthracnose, caused by Colletotrichum truncatum, leads to large-scale reduction in quality and yield in soybean production. Limited information is available regarding the molecular mechanisms of resistance to anthracnose in soybean. We conducted a transcriptomic and targeted metabolomic analysis of pods from two soybean lines, “Zhechun No. 3” (ZC3) and ZC-2, in response to C. truncatum infection. Factors contributing to the enhanced resistance of ZC-2 to anthracnose compared with that of ZC3, included signal transduction (jasmonic acid, auxin, mitogen-activated protein kinase, and Ca²⁺ signaling), transcription factors (WRKY and bHLH), resistance genes (PTI1, RPP13, RGA2, RPS6, and ULP2B), pathogenesis-related genes (chitinase and lipid transfer protein), and terpenoid metabolism. Targeted metabolomic analysis revealed that terpenoid metabolism responded more promptly and more intensely to C. truncatum infection in ZC-2 than in ZC3. In vitro antifungal activity and resistance induction test confirmed that jasmonic acid, auxin signaling and terpenoids played important roles in soybean resistance to anthracnose. This research is the first study to explore the molecular mechanisms of soybean resistance to anthracnose. The findings are important for in-depth analysis of molecular resistance mechanisms, discovery of resistance genes, and to expedite the breeding of anthracnose-resistant soybean cultivars.
... Colletotrichum truncatum was selected, among the phytopathogenic fungi available, as the only strain to test because very low amounts of both lipodespsipeptides and cylodipeptides were available for the antimicrobial assay. The strain of C. truncatum was isolated in Argentina as one of the most dangerous pathogens of soybean inducing anthracnose symptoms with severe epidemics and expressive yield losses. 44 All the lipodepsipeptides (tolaasins and WLIP) were produced, purified, and identified as reported in detail in the Materials and Methods section. The two derivatives of tolaasin I and the methyl ester of WLIP were prepared and characterized as reported in detail in the same section and in the Supporting Information. ...
Biotic stresses (fungi, bacteria, insects, weeds, etc.) are some of the most important causes of the decrease in the quality and quantity of crops that could become an emergency due to a noteworthy increase in the world population. Thus, to overcome these problems, massive use of chemical pesticides has been carried out with heavy consequences for environmental pollution and food safety. An eco-friendly alternative can be using natural compound-based biopesticides with high efficacy and selectivity. Some bacterial lipodepsipeptides (tolaasins I, II, A, D, and E and WLIP together with hexacetyl- and tetrahydro-tolaasin I and WLIP methyl ester) and cyclic dipeptides (cyclo(l-Pro-l-Tyr), cyclo(d-Pro-l-Tyr), cyclo(l-Pro-l-Val), and cyclo(l-Pro-l-Leu)) were assayed against several pathogenic bacteria and fungi of important agrarian plants. Lipodepsipeptides showed strong growth inhibition of all microorganisms tested in the range of 0.1-0.8 μg/mL, while cyclodipeptides, despite preserving this ability, showed a noteworthily reduced antimicrobial activity being active only in the range of 15-900 μg/mL. Among the lipodepsipeptides and cyclic dipeptides assayed, tolaasin d and cyclo(l-Pro-l-Tyr) (also named maculosin-1) appeared to be the most toxic compounds. Some structure-activity relationships of lipodepsipeptides were also discussed along with their practical application as biopesticides in agriculture.
... Similar anthracnose symptoms were also observed on the leaves of yam (D. alata) caused by C. gloeosporioides complex in different parts of Nigeria based on in vitro diagnosis of cultural and morphological characteristics [20]. Use of cultural and morphological characteristics has been reported useful in characterising other Colletotrichum species [21]. ...
This study was conducted to investigate a characteristic fungal disease, causing leaf anthracnose on B. edulis. A symptom progression from an angular-asymmetrical yellow discoloration to an ulcer-like necrosis caused death to the whole leaf. Colony pigmentations observed among the six isolates ranged from grey to white with slightly raised aerial mycelium to dense cottony mycelium. Most of the isolates showed salmon to bright orange spore-masses that were arranged in concentric rings, and with aging these orange spore-masses evenly distributed towards the culture peripheral. The conidial shapes of all of the isolates were straight and cylindrical with the average conidia length and width, ranged from 55.6-62.8 and 16.8-24µm. Together with differential tests using fungicide and a temperature regime revealed characteristics corresponding to Colletotrichum gloeosporioides.
