Clavicipitaceous fungi associated with ergoline alkaloid-containing convolvulaceae.

ABSTRACT

Ergoline alkaloids are a group of physiologically active natural products occurring in taxonomically unrelated fungal and plant taxa Clavicipitaceae (Hypocreales) and Convolvulaceae (Solanales). We show in the present paper that clavicipitaceous fungi are associated with four different ergoline alkaloid-containing plant taxa of the family Convolvulaceae. These fungi are macroscopically visible on the adaxial surface when young leaf buds are opened or are detectable by molecular biological techniques in seeds. Detectability of the fungus correlates with the absence or presence of ergoline alkaloids within the respective plant organ. The fungi contain the gene (dmaW) responsible for the committed step in ergoline alkaloid biosynthesis. Sequencing of ribosomal DNA (18S rDNA and internal transcribed spacer) as well as the dmaW gene (partial) and construction of phylogenetic trees show that the fungi are clavicipitaceous, not identical but very closely related.