Links between Genetic Groups, Indole Alkaloid Profiles and Ecology within the Grass-Parasitic Claviceps purpurea Species Complex

Abstract

The grass parasitic fungus Claviceps purpurea sensu lato produces sclerotia with toxic indole alkaloids. It constitutes several genetic groups with divergent habitat preferences that recently were delimited into separate proposed species. We aimed to 1) analyze genetic variation of C. purpurea sensu lato in Norway, 2) characterize the associated indole alkaloid profiles, and 3) explore relationships between genetics, alkaloid chemistry and ecology. Approximately 600 sclerotia from 14 different grass species were subjected to various analyses including DNA sequencing and HPLC-MS. Molecular results, supported by chemical and ecological data, revealed one new genetic group (G4) in addition to two of the three known; G1 (C. purpurea sensu stricto) and G2 (C. humidiphila). G3 (C. spartinae) was not found. G4, which was apparently con-specific with the recently described C. arundinis sp. nov, was predominantly found in very wet habitats on Molinia caerulea and infrequently in saline habitats on Leymus arenarius. Its indole-diterpene profile resembled G2, while its ergot alkaloid profile differed from G2 in high amounts of ergosedmam. In contrast to G1, indole-diterpenes were consistently present in G2 and G4. Our study supports and complements the newly proposed species delimitation of the C. purpurea complex, but challenges some species characteristics including host spectrum, habitat preferences and sclerotial floating ability.

Ergot Alkaloids of the Family Clavicipitaceae

“…Ergot fungi ( Claviceps species) produce an even wider spectrum of ergot alkaloids. Strains of Claviceps purpurea are capable of producing ergonovine and the complex ergopeptines because their EAS clusters include all known ergot-alkaloid genes except easO and easP (Negård et al 2015; Schardl et al 2013c). In addition, Claviceps purpurea strain 20.1 has two very similar lpsA genes ( lpsA1 and lpsA2 ), due to tandem duplication and neofunctionalization, to give ergotamine and ergocryptine as its two main ergopeptines (Haarmann et al 2008).…”

Ergot species of the Claviceps purpurea group from South Africa

“…Among them some species of the C. purpurea species group are unique by way of their host range. An extreme example is C. purpurea infecting various unrelated lineages of Pooideae or C. humidiphila and C. arundinis with hosts belonging to both to Arundinoideae and Pooideae (Negård et al 2015;Pažoutová et al 2015). The same is true for C. pazoutovae which was found on Ehrhartoideae as well as Pooideae.…”

Ergot Alkaloids and their Hallucinogenic Potential in Morning Glories

“…People appear drowsy, lethargic, and suffer from double vision and hallucinations. Due to the habitat preferences of different Claviceps strains [19], convulsive ergotism prevailed east and north, however, gangrenous west of the river Rhine [14].…”