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1.
Mycotoxin Res ; 40(1): 1-17, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37953416

RESUMO

Ergot alkaloids are secondary metabolites that are produced by fungi and contaminate cereal crops and grasses. The ergot alkaloids produced by Claviceps purpurea are the most abundant worldwide. The metabolites exist in two configurations, the C-8-R-isomer (R-epimer) and the C-8-S-isomer (S-epimer). These two configurations can interconvert to one another. Ergot alkaloids cause toxic effects after consumption of ergot-contaminated food and feed at various concentrations. For bioactivity reasons, the C-8-R-isomers have been studied to a greater extent than the C-8-S-isomer since the C-8-S-isomers were considered biologically inactive. However, recent studies suggest the contrary. Analytical assessment of ergot alkaloids now includes the C-8-S-isomers and high concentrations of specific C-8-S-isomers have been identified. The inclusion of the C-8-S-isomer in regulatory standards is reviewed. This review has identified that further research into the C-8-S-isomers of ergot alkaloids is warranted. In addition, the inclusion of the C-8-S-isomers into regulatory recommendations worldwide for food and feed should be implemented. The objectives of this review are to provide an overview of historic and current studies that have assessed the C-8-S-isomers. Specifically, this review will compare the C-8-R-isomers to the C-8-S-isomers with an emphasis on the biological activity and analytical assessment.


Assuntos
Claviceps , Alcaloides de Claviceps , Compostos Heterocíclicos de 4 ou mais Anéis
2.
Molecules ; 28(20)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37894711

RESUMO

Ergot alkaloids are secondary metabolites resulting from fungi of the genus Claviceps that have proven to be highly toxic. These mycotoxins commonly infect cereal crops such as wheat, rye, barley, and oats. Due to the increase worldwide consumption of cereal and cereal-based products, the presence of ergot alkaloids in food presents a concern for human safety. For this reason, it is essential to develop several analytical methods that allow the detection of these toxic compounds. This review compiles and discusses the most relevant studies and methods used in the detection and quantification of ergot alkaloids. Moreover, the decontamination techniques are also addressed, with special attention to sorting, cleaning, frying, baking, peeling, and ammonization methods, as they are the only ones already applied to ergot alkaloids.


Assuntos
Claviceps , Alcaloides de Claviceps , Micotoxinas , Humanos , Grão Comestível/química , Micotoxinas/análise , Compostos Heterocíclicos de 4 ou mais Anéis , Agonistas de Dopamina , Contaminação de Alimentos/análise
3.
J Food Prot ; 86(3): 100046, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36916553

RESUMO

Claviceps purpurea (Fr.) Tul is the causal organism for ergot impacting grass hosts, including wheat. The pathogen produces ergot alkaloids (EAs) during the development of mature sclerotia leading to potential wheat quality discounts or rejection at the point of sale. Cultural practices are recommended for the management of ergot in wheat, but there is limited information pertaining to the use of in-season fungicides to help reduce ergot. The objective of this research was to evaluate the efficacy of four fungicides (prothioconazole + metconazole, pydiflumetofen + propiconazole, azoxystrobin + propiconazole, and fluxapyroxad + pyraclostrobin) on sclerotia characteristics, and EAs associated with C. purpurea. A field experiment was established using a male-sterile hard red spring line with fungicide applications occurring at complete full head emergence (Feekes Growth Stage 10.5). Individual plots were harvested and cleaned, and ergot sclerotia were collected. Physical characteristics and toxin production were examined. Fungicides had a significant (p < .05) impact on total ergot body weight (EBW), with all fungicides having lower EBW than the nontreated control. The fungicide premixture of pydiflumetofen + propiconazole had the lowest EBW among all treatments. Fluxapyroxad + pyraclostrobin had the lowest levels of EAs among fungicides. Results suggest that fungicide premixtures can potentially reduce EBW and influence EA production in wheat.


Assuntos
Claviceps , Alcaloides de Claviceps , Fungicidas Industriais , Triticum , Fungicidas Industriais/farmacologia , Alcaloides de Claviceps/farmacologia
4.
J Nat Med ; 77(2): 306-314, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36635416

RESUMO

The genus Claviceps (Clavicipitaceae) is famous for producing ergot alkaloids (EAs) in sclerotia. EAs can cause ergotism, resulting in convulsions and necrosis when ingested, making these compounds a serious concern for food safety. Agroclavine (2), a typical Clavine-type EA, is a causative agent of ergotism and is listed as a compound to be monitored by the European Food Safety Authority. Clavine-type EAs are known to cause cytotoxicity, but the mechanism has not been elucidated. We performed annexin V and PI double-staining followed by flow cytometric analysis to detect apoptosis in HepG2 and PANC-1 cells after exposure to Clavine-type EAs. Clavine-type EAs reduced cell viability and induced apoptosis in both cell lines. We then performed LC-MS analysis of EAs from 41 sclerotia samples of Claviceps collected in Japan. 24 out of 41 sclerotia extracts include peptide-type EAs (ergosine/inine: 4/4', ergotamine: 5, ergocornine/inine: 6/6', α-ergocryptine/inine: 8/8', and ergocristine/inine: 9/9') and 19 sclerotia extracts among 24 sclerotia detected peptide type EAs include Clavine-type EAs (pyroclavine: 1, agroclavine: 2, festuclavine: 3) by LC-MS. We then performed a metabolomic analysis of the EAs in the sclerotia using principal component analysis (PCA). The PCA score plots calculated for EAs suggested the existence of four groups with different EA production patterns. One of the groups was formed by the contribution of Clavine-type EAs. These results suggest that Clavine-type EAs are a family of compounds requiring attention in food safety and livestock production in Japan.


Assuntos
Claviceps , Alcaloides de Claviceps , Ergotismo , Humanos , Alcaloides de Claviceps/análise , Alcaloides de Claviceps/química , Japão , Claviceps/química , Claviceps/metabolismo , Peptídeos , Apoptose
5.
Br J Clin Pharmacol ; 89(4): 1304-1317, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36630197

RESUMO

Dopamine agonists are a key tool in the therapeutic arsenal of endocrinologists worldwide. They exert their effects by binding to dopamine-2 (D2) receptors expressed by pituitary tumour cells to modulate hormonal secretion and tumour size. They are the established first-line treatment for prolactinomas which express high levels of D2 receptors. Growing data support their use as an adjuvant treatment option for other pituitary tumours including growth hormone, adrenocorticotrophic hormones, thyroid hormone secreting adenomas and nonfunctional pituitary tumours, all of which have been shown to express D2 receptors as well, albeit to varying extents. For those pituitary tumours inadequately treated by dopamine agonist alone, combined agonism of D2 and somatostatin receptors represent a new frontier in clinical development. Here we review the development and role of dopamine agonist for the treatment of prolactinomas, the literature supporting their adjuvant use for the treatment of all other pituitary tumours, and recent progress in the development of the next generation of chimeric compounds that target D2 and other receptor subtypes highly expressed on pituitary tumour cells.


Assuntos
Agonistas de Dopamina , Neoplasias Hipofisárias , Prolactinoma , Humanos , Adenoma/tratamento farmacológico , Adenoma/metabolismo , Agonistas de Dopamina/farmacologia , Agonistas de Dopamina/uso terapêutico , Neoplasias Hipofisárias/tratamento farmacológico , Prolactinoma/tratamento farmacológico , Somatostatina/metabolismo , Somatostatina/uso terapêutico , Claviceps/química , Produtos Biológicos/uso terapêutico
6.
PLoS One ; 18(1): e0279616, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656815

RESUMO

BACKGROUND: Alzheimer's disease (AD) is a form of dementia that strikes elderly people more frequently than it does younger people. The cognitive skills and memory of Alzheimer's sufferers continue to deteriorate over time. Recent studies have shown that patients with AD have greater amounts of inflammatory markers in their bodies, which suggests that inflammation occurs early on in the progression of the disease. There is a possibility that Aß oligomers and fibrils can be recognised by TLRs, in addition to the microglial receptors CD14, CD36, and CD47. When Aß binds to either CD36 or TLR4, it sets off a chain reaction of inflammatory chemokines and cytokines that ultimately results in neurodegeneration. Diabetes and Alzheimer's disease have both been recently related to TLR4. The activation of TLR4 has been connected to a variety of clinical difficulties that are associated with diabetes, in addition to the internal environment of the body and the microenvironment of the brain. TLR4 inhibitors have been shown in clinical investigations to not only lessen the likelihood of getting sick but also to increase the average longevity. RESULT: In this work we used molecular docking and molecular dynamics modelling to investigate the effectiveness of FDA-approved antidiabetic plant derived drugs in combating the TLR4 receptor. Molecular docking experiments were used to make a prediction regarding the most important interactions involving 2-Bromoergocryptine Mesylate. With a binding affinity of -8.26 kcal/mol, it stood out from the other candidates as the one with the greatest potential. To verify the interaction pattern that takes place between 2-Bromoergocryptine Mesylate and the TLR4 receptor, a molecular dynamic simulation was run at a time scale of 150 nanoseconds. Because of this, 2-Bromoergocryptine Mesylate was able to make substantial contact with the active site, which led to increased structural stability during the process of the complex's dynamic development. CONCLUSION: As a result of this, the results of our research may be relevant for future research into the efficacy of 2-bromoergocryptine mesylate as a potential lead treatment for TLR4 receptors in intracranial aneurysm rupture in AD.


Assuntos
Doença de Alzheimer , Bromocriptina , Claviceps , Aneurisma Intracraniano , Receptor 4 Toll-Like , Humanos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Bromocriptina/farmacologia , Aneurisma Intracraniano/prevenção & controle , Simulação de Acoplamento Molecular , Receptor 4 Toll-Like/metabolismo , Triticum/microbiologia
7.
Fungal Biol ; 126(11-12): 752-763, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36517143

RESUMO

Ergot, the genus Claviceps comprises several deeply diverged lineages, recently classified as sections. Among them, the section Pusillae, is the most speciose, with a centre of distribution in Africa but occurring worldwide, often as a consequence of its invasive potential. This section includes the most severe plant pathogens such as Claviceps africana and C. gigantea, responsible for toxicoses and a significant reduction in the seed yields of Sorghum and Zea. In this study we surveyed ergot diversity in South Africa, focusing on grasses native to this region, but known for their high potential of invasiveness. The revision based on molecular and phenotypic markers revealed 16 species, with a high proportion of undescribed diversity, confirming Africa as a hot spot for this section. Five new species, Claviceps tulasnei, Claviceps eulaliae, Claviceps hypertheliae, Claviceps fredericksoniae and Claviceps arundinellae were described from Setaria, Eulalia, Hyperthelia, Miscanthus and Arundinella respectively. Claviceps texensis infecting Cenchrus, previously only identified from the same host in Texas, USA, was confirmed to be present in Africa, which is assumed to be its primary area of distribution. In addition, the host grass genus Anthephora is newly reported as a host of Claviceps digitariae. The most of the taxa were negligible concerning alkaloid production, with the exception of C. fredericksoniae, which is a sister of potent alkaloid producer C. africana, and produces mainly DH-ergosine, together with traces of DH-ergocornine. The host/parasite associations within Pusillae section is very narrow, suggesting that co-speciation is the major speciation driver in this group. Host grasses of the described species are already recognised invasive species and their ovarial parasites need to be monitored. This is highlighted by the fact that all Pusillae produced air-borne secondary conidia, which is autapomorphy of this section and considered to be important for their invasive abilities.


Assuntos
Claviceps , Alcaloides de Claviceps , Humanos , Claviceps/genética , Poaceae , África do Sul , População Africana
8.
Molecules ; 27(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36364148

RESUMO

Ergot is the spore form of the fungus Claviceps purpurea. Ergot alkaloids are indole compounds that are biosynthetically derived from L-tryptophan and represent the largest group of fungal nitrogen metabolites found in nature. The common part of ergot alkaloids is lysergic acid. This review shows the importance of lysergic acid as a representative of ergot alkaloids. The subject of ergot and its alkaloids is presented, with a particular focus on lysergic acid. All methods of total lysergic acid synthesis-through Woodward, Hendrickson, and Szantay intermediates and Heck coupling methods-are presented. The topic of biosynthesis is also discussed.


Assuntos
Claviceps , Alcaloides de Claviceps , Ácido Lisérgico , Ácido Lisérgico/metabolismo , Claviceps/metabolismo
9.
Toxins (Basel) ; 14(9)2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-36136518

RESUMO

As the contamination of cereal grains with ergot has been increasing in Western Canada, studies were undertaken to evaluate the impacts of heating (60, 80, 120, or 190 °C) alone or in combination with pelleting on concentrations of ergot alkaloids. Fifteen samples of ergot-contaminated grain from Alberta and Saskatchewan were assayed for R and S epimers of six alkaloids (ergocryptine, ergocristine, ergocornine, ergometrine, ergosine, and ergotamine) using HPLC MS/MS. Five samples with distinct alkaloid profiles were then selected for heating and pelleting studies. Heating resulted in a linear increase (p < 0.05) of total R and total S epimers with increasing temperature, although some individual R epimers were stable (ergometrine, ergosine, ergotamine). Pelleting also increased (p < 0.05) concentrations of total R and total S epimers detected, although ergometrine concentration decreased (p < 0.05) after pelleting. A feeding study arranged in a 2 × 2 factorial structure used 48 backgrounding Angus-cross steers fed four different diets: (1) Control Mash (CM, no added ergot), (2) Control Pellet (CP), (3) Ergot Mash (EM), or (4) Ergot Pellet (EP). Pelleting heated the ergot to 90−100 °C under 4 bars pressure, but the ergot used in the feeding study was not otherwise heated. Alkaloid concentrations of EM and EP varied by up to 1.1 mg/kg depending on the feed matrix assayed. No differences among treatments were noted for growth performance, feed intake, feed conversion, concentrations of serum prolactin and haptoglobin, hair cortisol, or in temperatures of extremities measured by infrared thermography. The only negative impacts of ergot alkaloids were on blood parameters indicative of reduced immune function or chronic inflammation. Pelleting did not heighten the negative clinical outcomes of ergot, although alkaloid concentrations of pelleted feed increased depending on the matrix assayed. It was hypothesized that the heat and pressure associated with pelleting may enhance the recovery of alkaloids from pelleted feed.


Assuntos
Claviceps , Alcaloides de Claviceps , Alberta , Ração Animal/análise , Animais , Bovinos , Claviceps/química , Grão Comestível/química , Ergonovina/análise , Alcaloides de Claviceps/análise , Ergotamina/análise , Ergotaminas/análise , Haptoglobinas/análise , Calefação , Hidrocortisona , Prolactina , Espectrometria de Massas em Tandem/métodos
10.
J Agric Food Chem ; 70(29): 8931-8941, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35830571

RESUMO

Detoxification of ergot-contaminated feed by ammonia would be a practical application, given that ammonia is routinely used in the agriculture industry. To assess the effects of ammonia on ergot alkaloids, natural ergot-contaminated wheat was ammoniated. The total concentration of ergot alkaloids (R- and S-epimers) decreased after exposure to ammonia (8-29%). Separately, the total R-epimers decreased in concentration (40-66%), whereas the total S-epimers increased (21-81%). Specific ergot alkaloids demonstrated degradation and/or epimerization after exposure to ammonia, potentially associated with structural differences, and influenced the total concentrations observed. Ammonization of ergot standards resulted in potential degradation products and epimerization, supporting the above results. The use of ultrahigh-performance liquid chromatography-tandem mass spectrometry provides an updated assessment of the detoxification potential of ammonia for ergot alkaloids and the quantification of the S-epimers. Ammonia alters the R- and S-epimers of ergot alkaloids, which may lead to a potential practical detoxification process of ergot-contaminated feed.


Assuntos
Claviceps , Alcaloides de Claviceps , Amônia , Cromatografia Líquida de Alta Pressão/métodos , Alcaloides de Claviceps/análise , Contaminação de Alimentos/análise , Compostos Heterocíclicos de 4 ou mais Anéis , Triticum/química
11.
PLoS One ; 17(2): e0263496, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35143550

RESUMO

Pangenome analyses are increasingly being utilized to study the evolution of eukaryotic organisms. While pangenomes can provide insight into polymorphic gene content, inferences about the ecological and adaptive potential of such organisms also need to be accompanied by additional supportive genomic analyses. In this study we constructed a pangenome of Claviceps purpurea from 24 genomes and examined the positive selection and recombination landscape of an economically important fungal organism for pharmacology and agricultural research. Together, these analyses revealed that C. purpurea has a relatively large accessory genome (~ 38%), high recombination rates (ρ = 0.044), and transposon mediated gene duplication. However, due to observations of relatively low transposable element (TE) content (8.8%) and a lack of variability in genome sizes, prolific TE expansion may be controlled by frequent recombination. We additionally identified that within the ergoline biosynthetic cluster the lpsA1 and lpsA2 were the result of a recombination event. However, the high recombination rates observed in C. purpurea may be influencing an overall trend of purifying selection across the genome. These results showcase the use of selection and recombination landscapes to identify mechanisms contributing to pangenome structure and primary factors influencing the evolution of an organism.


Assuntos
Claviceps/genética , Genoma Fúngico , Recombinação Genética , Elementos de DNA Transponíveis , Especificidade de Hospedeiro , Polimorfismo de Nucleotídeo Único , Seleção Genética
12.
Metab Eng ; 69: 198-208, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34902590

RESUMO

Privileged ergot alkaloids (EAs) produced by the fungal genus Claviceps are used to treat a wide range of diseases. However, their use and research have been hampered by the challenging genetic engineering of Claviceps. Here we systematically refactored and rationally engineered the EA biosynthetic pathway in heterologous host Aspergillus nidulans by using a Fungal-Yeast-Shuttle-Vector protocol. The obtained strains allowed the production of diverse EAs and related intermediates, including prechanoclavine (PCC, 333.8 mg/L), chanoclavine (CC, 241.0 mg/L), agroclavine (AC, 78.7 mg/L), and festuclavine (FC, 99.2 mg/L), etc. This fungal platform also enabled the access to the methyl-oxidized EAs (MOEAs), including elymoclavine (EC), lysergic acid (LA), dihydroelysergol (DHLG), and dihydrolysergic acid (DHLA), by overexpressing a P450 enzyme CloA. Furthermore, by optimizing the P450 electron transfer (ET) pathway and using multi-copy of cloA, the titers of EC and DHLG have been improved by 17.3- and 9.4-fold, respectively. Beyond our demonstration of A. nidulans as a robust platform for EA overproduction, our study offers a proof of concept for engineering the eukaryotic P450s-contained biosynthetic pathways in a filamentous fungal host.


Assuntos
Claviceps , Alcaloides de Claviceps , Vias Biossintéticas/genética , Claviceps/genética , Claviceps/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Alcaloides de Claviceps/genética , Alcaloides de Claviceps/metabolismo , Saccharomyces cerevisiae/metabolismo
13.
Phytopathology ; 112(4): 842-851, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34698539

RESUMO

Partial resistance to the biotrophic fungal pathogen Claviceps purpurea, causal agent of ergot, has been found that colocates with mutant alleles of the wheat Reduced height (Rht) loci on chromosomes 4B and 4D. These Rht loci represent the wheat orthologs of the Arabidopsis Della genes. To investigate the role of the Rht mutant DELLA proteins in ergot resistance, we assessed C. purpurea infection in wheat near-isogenic lines (NILs) carrying the gibberellic acid (GA)-insensitive semidwarf alleles Rht-B1b and Rht-D1b and the severe dwarf alleles Rht-B1c and Rht-D1c. NILs of the GA-sensitive alleles Rht8 (chromosome 2D) and Rht12 (chromosome 5A) were also included. A general trend toward increased resistance to C. purpurea, with smaller and lighter sclerotia, was observed on the NILs Rht-B1b, Rht-D1b, Rht-B1c, and Rht-D1c, and also on Rht8. Levels of the bioactive GA4 and the auxin indole-3-acetic acid increased after inoculation with C. purpurea, following similar patterns and implicating a potential auxin-mediated induction of GA biosynthesis. In contrast, jasmonic acid (JA) levels fell in the parental lines 'Mercia' and 'Maris Huntsman' after inoculation with C. purpurea, but increased in all the Rht-mutant NILs. Inoculation with C. purpurea did not show any informative changes in the levels of salicylic acid. Our results suggest that GA-mediated degradation of the DELLA proteins and down-regulation of JA-signaling pathways supports infection of wheat by C. purpurea. As these responses are generally associated with necrotrophic fungal pathogens, we propose that the biotroph C. purpurea may have a necrotrophic growth stage.


Assuntos
Triticum , Claviceps/genética , Hormônios/metabolismo , Ácidos Indolacéticos/metabolismo , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/metabolismo
14.
Clin Dermatol ; 39(6): 1088-1094, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34920829

RESUMO

It has been widely accepted that ergot is a fungal disease caused by infection with the parasitic Claviceps purpurea leading to the development of typical black kernels n the plant. Ingestion of infected rye grains containing ergot alkaloids-usually in the form of contaminated rye bread-causes poisoning, also known as ergotism. The negative impacts of ergot contamination of grain on the health of humans and animals were first documented in ancient times. The history of ergotism shows the influence of food on human health. Although ergot has been known for ages, until the 18th century, its nature was not recognized. It was a part of the rye plant and it was used in traditional medicine. The diet was based was mostly on rye that led to neurologic disorders and gangrene. In the Middle Ages, in regions where rye was a dietary staple, many cases of a peculiar epidemic were recorded. Two names are usually used to describe it: "Saint Anthony's fire" and "holy fire," although there are many more appellations. The history of ergotism is a very important part of history of dermatology. The saint who people prayed to for protection against the disease was Anthony the Great (251-356). Monks of the Order of Saint Anthony played a particular role in treating ergotism by natural methods and specialized in treating skin diseases. Ergot alkaloids still pose a risk to human and animal safety if they appear in food.


Assuntos
Ergotismo , Animais , Claviceps , Ergotismo/epidemiologia , Alimentos , Humanos
15.
Toxins (Basel) ; 13(12)2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34941699

RESUMO

Research into ergot alkaloid production in major cereal cash crops is crucial for furthering our understanding of the potential toxicological impacts of Claviceps purpurea upon Canadian agriculture and to ensure consumer safety. An untargeted metabolomics approach profiling extracts of C. purpurea sclerotia from four different grain crops separated the C. purpurea strains into two distinct metabolomic classes based on ergot alkaloid content. Variances in C. purpurea alkaloid profiles were correlated to genetic differences within the lpsA gene of the ergot alkaloid biosynthetic gene cluster from previously published genomes and from newly sequenced, long-read genome assemblies of Canadian strains. Based on gene cluster composition and unique polymorphisms, we hypothesize that the alkaloid content of C. purpurea sclerotia is currently undergoing adaptation. The patterns of lpsA gene diversity described in this small subset of Canadian strains provides a remarkable framework for understanding accelerated evolution of ergot alkaloid production in Claviceps purpurea.


Assuntos
Claviceps/genética , Alcaloides de Claviceps/biossíntese , Micotoxinas/química , Canadá , Claviceps/metabolismo , Grão Comestível/microbiologia , Alcaloides de Claviceps/genética , Variação Genética , Micotoxinas/genética , Secale/microbiologia , Triticale/microbiologia , Triticum/microbiologia
16.
Toxins (Basel) ; 13(11)2021 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-34822583

RESUMO

Ergot fungi (Claviceps spp.) are infamous for producing sclerotia containing a wide spectrum of ergot alkaloids (EA) toxic to humans and animals, making them nefarious villains in the agricultural and food industries, but also treasures for pharmaceuticals. In addition to three classes of EAs, several species also produce paspaline-derived indole diterpenes (IDT) that cause ataxia and staggers in livestock. Furthermore, two other types of alkaloids, i.e., loline (LOL) and peramine (PER), found in Epichloë spp., close relatives of Claviceps, have shown beneficial effects on host plants without evidence of toxicity to mammals. The gene clusters associated with the production of these alkaloids are known. We examined genomes of 53 strains of 19 Claviceps spp. to screen for these genes, aiming to understand the evolutionary patterns of these genes across the genus through phylogenetic and DNA polymorphism analyses. Our results showed (1) varied numbers of eas genes in C. sect. Claviceps and sect. Pusillae, none in sect. Citrinae, six idt/ltm genes in sect. Claviceps (except four in C. cyperi), zero to one partial (idtG) in sect. Pusillae, and four in sect. Citrinae, (2) two to three copies of dmaW, easE, easF, idt/ltmB, itd/ltmQ in sect. Claviceps, (3) frequent gene gains and losses, and (4) an evolutionary hourglass pattern in the intra-specific eas gene diversity and divergence in C. purpurea.


Assuntos
Claviceps/genética , Alcaloides de Claviceps/biossíntese , Genes Fúngicos/genética , Alcaloides Indólicos/isolamento & purificação , Claviceps/metabolismo , Evolução Molecular , Família Multigênica , Filogenia
17.
BMC Genomics ; 22(1): 766, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34702162

RESUMO

BACKGROUND: The phytopatogen Claviceps paspali is the causal agent of Ergot disease in Paspalum spp., which includes highly productive forage grasses such as P. dilatatum. This disease impacts dairy and beef production by affecting seed quality and producing mycotoxins that can affect performance in feeding animals. The molecular basis of pathogenicity of C. paspali remains unknown, which makes it more difficult to find solutions for this problem. Secreted proteins are related to fungi virulence and can manipulate plant immunity acting on different subcellular localizations. Therefore, identifying and characterizing secreted proteins in phytopathogenic fungi will provide a better understanding of how they overcome host defense and cause disease. The aim of this work is to analyze the whole genome sequences of three C. paspali isolates to obtain a comparative genome characterization based on possible secreted proteins and pathogenicity factors present in their genome. In planta RNA-seq analysis at an early stage of the interaction of C. paspali with P. dilatatum stigmas was also conducted in order to determine possible secreted proteins expressed in the infection process. RESULTS: C. paspali isolates had compact genomes and secretome which accounted for 4.6-4.9% of the predicted proteomes. More than 50% of the predicted secretome had no homology to known proteins. RNA-Seq revealed that three protein-coding genes predicted as secreted have mayor expression changes during 1 dpi vs 4 dpi. Also, three of the first 10 highly expressed genes in both time points were predicted as effector-like. CAZyme-like proteins were found in the predicted secretome and the most abundant family could be associated to pectine degradation. Based on this, pectine could be a main component affected by the cell wall degrading enzymes of C. paspali. CONCLUSIONS: Based on predictions from DNA sequence and RNA-seq, unique probable secreted proteins and probable pathogenicity factors were identified in C. paspali isolates. This information opens new avenues in the study of the biology of this fungus and how it modulates the interaction with its host. Knowledge of the diversity of the secretome and putative pathogenicity genes should facilitate future research in disease management of Claviceps spp.


Assuntos
Claviceps , Micotoxinas , Paspalum , Animais , Bovinos , Claviceps/genética , Virulência
18.
J Nat Prod ; 84(10): 2630-2643, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34553942

RESUMO

Claviceps purpurea is an ergot fungus known for its neurotropic alkaloids, which have been identified as the main cause of ergotism, a livestock and human disease triggered by ergot consumption. Tetrahydroxanthone dimers, the so-called ergopigments, presumably also contribute to this toxic effect. Overexpression of the cluster-specific transcription factor responsible for the formation of these pigments in C. purpurea led to the isolation of three new metabolites (8-10). The new pigments were characterized utilizing HRMS, NMR techniques, and CD spectroscopy and shown to be xanthone dimers. Secalonic acid A and its 2,4'- and 4,4'-linked isomers were also isolated, and their absolute configuration was investigated. The contribution of secalonic acid A, its isomers, and new metabolites to the toxicity of C. purpurea was investigated in HepG2 and CCF-STTG1 cells. Along with cytotoxic properties, secalonic acid A was found to inhibit topoisomerase I and II activity.


Assuntos
Claviceps/química , Xantenos/química , Células Hep G2 , Humanos , Estrutura Molecular , Inibidores da Topoisomerase , Xantonas
19.
Toxins (Basel) ; 13(7)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34357964

RESUMO

In the past centuries consumption of bread made of ergot-infected flour resulted in mass poisonings and miscarriages. The reason was the sclerotia of Claviceps purpurea (Fr.) Tul.-a source of noxious ergot alkaloids (ergotamine and ergovaline). The authors have searched the 19th century medical literature in order to find information on the following topics: dosage forms of drugs based on ergot and their application in official gynecology and obstetrics. The authors also briefly address the relevant data from the previous periods as well as the 20th century research on ergot. The research resulted in a conclusion that applications of ergot in gynecology and obstetrics in the 19th century were limited to controlling excessive uterine bleeding and irregular spasms, treatment of fibrous tumors of the uterus, and prevention of miscarriage, abortion, and amenorrhoea. The most common dosage forms mentioned in the works included in our review were the following: tinctures, water extracts (Wernich's and Squibb's watery extract of ergot), pills, and powders. The information documented in this paper will be helpful for further research and helpful in broadening the understanding of the historical application of the described controversial crude drugs. Ergot alkaloids were widely used in obstetrics, but in modern times they are not used in developed countries anymore. They may, however, play a significant role in developing countries where, in some cases, they can be used as an anti-hemorrhage agent during labor.


Assuntos
Alcaloides de Claviceps/uso terapêutico , Claviceps , Ergotamina , Ergotaminas , Ginecologia , Dietilamida do Ácido Lisérgico/análogos & derivados , Obstetrícia
20.
BMC Plant Biol ; 21(1): 316, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215204

RESUMO

BACKGROUND: Ergot, caused by the fungal pathogen Claviceps purpurea, infects the female flowers of a range of cereal crops, including wheat. To understand the interaction between C. purpurea and hexaploid wheat we undertook an extensive examination of the reprogramming of the wheat transcriptome in response to C. purpurea infection through floral tissues (i.e. the stigma, transmitting and base ovule tissues of the ovary) and over time. RESULTS: C. purpurea hyphae were observed to have grown into and down the stigma at 24 h (H) after inoculation. By 48H hyphae had grown through the transmitting tissue into the base, while by 72H hyphae had surrounded the ovule. By 5 days (D) the ovule had been replaced by fungal tissue. Differential gene expression was first observed at 1H in the stigma tissue. Many of the wheat genes differentially transcribed in response to C. purpurea infection were associated with plant hormones and included the ethylene (ET), auxin, cytokinin, gibberellic acid (GA), salicylic acid and jasmonic acid (JA) biosynthetic and signaling pathways. Hormone-associated genes were first detected in the stigma and base tissues at 24H, but not in the transmitting tissue. Genes associated with GA and JA pathways were seen in the stigma at 24H, while JA and ET-associated genes were identified in the base at 24H. In addition, several defence-related genes were differential expressed in response to C. purpurea infection, including antifungal proteins, endocytosis/exocytosis-related proteins, NBS-LRR class proteins, genes involved in programmed cell death, receptor protein kinases and transcription factors. Of particular interest was the identification of differential expression of wheat genes in the base tissue well before the appearance of fungal hyphae, suggesting that a mobile signal, either pathogen or plant-derived, is delivered to the base prior to colonisation. CONCLUSIONS: Multiple host hormone biosynthesis and signalling pathways were significantly perturbed from an early stage in the wheat - C. purpurea interaction. Differential gene expression at the base of the ovary, ahead of arrival of the pathogen, indicated the potential presence of a long-distance signal modifying host gene expression.


Assuntos
Claviceps/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Transcriptoma/genética , Triticum/genética , Triticum/microbiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Reguladores de Crescimento de Plantas/farmacologia , RNA-Seq , Fatores de Tempo , Triticum/efeitos dos fármacos
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