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.

• Keywords
• ergot alkaloids, ergot fungi, gene divergence, gene diversity, indole diterpenes, phylogeny, secondary metabolites,
• MeSH
• Claviceps genetics   metabolism   MeSH
• Phylogeny MeSH
• Genes, Fungal genetics   MeSH
• Indole Alkaloids isolation & purification   MeSH
• Evolution, Molecular MeSH
• Multigene Family MeSH
• Ergot Alkaloids biosynthesis   MeSH
• Publication type
• Journal Article MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• Indole Alkaloids MeSH
• Ergot Alkaloids MeSH

Among 18 tested strains of Claviceps spp., 7 produced significant amounts of exocellular polysaccharide (EPS). The maximum production of EPS was found in fermentation broth of Claviceps viridis. The kinetics of growth, substrate consumption, and EPS production in the batch, aerobic, submerged culture of this fungus were investigated in detail. The experimental data were processed by a simple mathematical model describing mass balance of growth, substrate consumption, formation of intermediates, and production of EPS. The parameters of the model were estimated from data obtained in cultivation performed in flasks and two laboratory fermentors of different size. Physiological similarity was obtained during process scale-up in volumetric ratio 1:100. The sugar consumption efficiency (52%) and observed EPS productivity (1.9 kg/m3 per d) were comparable with literature data.

• MeSH
• Models, Biological MeSH
• Biomass MeSH
• Claviceps growth & development   metabolism   MeSH
• Fermentation MeSH
• Glucans biosynthesis   MeSH
• Kinetics MeSH
• Culture Media MeSH
• Oxygen metabolism   MeSH
• Solubility MeSH
• Sucrose metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Glucans MeSH
• Culture Media MeSH
• Oxygen MeSH
• Sucrose MeSH

We studied genetic variability of 100 isolates of Claviceps purpurea by using randomly amplified polymorphic DNA (RAPD), an EcoRI restriction site polymorphism in the 5.8S ribosomal DNA (rDNA), the alkaloids produced, and conidial morphology. We identified three groups: (i) group G1 from fields and open meadows (57 isolates), (ii) group G2 from shady or wet habitats (41 isolates), and (iii) group G3 from Spartina anglica from salt marshes (2 isolates). The sclerotia of G1 isolates contained ergotamines and ergotoxines; G2 isolates produced ergosine and ergocristine along with small amounts of ergocryptine; and G3 isolates produced ergocristine and ergocryptine. The conidia of G1 isolates were 5 to 8 microm long, the conidia of G2 isolates were 7 to 10 microm long, and the conidia of G3 isolates were 10 to 12 microm long. Sclerotia of the G2 and G3 isolates floated on water. In the 5.8S rDNA analysis, an EcoRI site was found in G1 and G3 isolates but not in G2 isolates. The host preferences of the groups were not absolute, and there were host genera that were common to both G1 and G2; the presence of members of different groups in the same locality was rare. Without the use of RAPD or rDNA polymorphism, it was not possible to distinguish the three groups solely on the basis of phenotype, host, or habitat. In general, populations of C. purpurea are not host specialized, as previously assumed, but they are habitat specialized, and collecting strategies and toxin risk assessments should be changed to reflect this paradigm shift.

• MeSH
• Alkaloids biosynthesis   MeSH
• Claviceps genetics   isolation & purification   metabolism   MeSH
• DNA Primers genetics   MeSH
• Phenotype MeSH
• RNA, Fungal genetics   MeSH
• Genetic Variation MeSH
• Polymorphism, Restriction Fragment Length MeSH
• RNA, Ribosomal, 5.8S genetics   MeSH
• Plants microbiology   MeSH
• Base Sequence MeSH
• Random Amplified Polymorphic DNA Technique MeSH
• Environment MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Alkaloids MeSH
• DNA Primers MeSH
• RNA, Fungal MeSH
• RNA, Ribosomal, 5.8S MeSH