Molecular characterization of a seed transmitted clavicipitaceous fungus occurring on dicotyledoneous plants (Convolvulaceae).
Ergoline alkaloids (syn. ergot alkaloids) are constituents of clavicipitaceous fungi (Ascomycota) and of one particular dicotyledonous plant family, the Convolvulaceae. While the biology of fungal ergoline alkaloids is rather well understood, the evolutionary and biosynthetic origin of ergoline alkaloids within the family Convolvulaceae is unknown. To investigate the possible origin of ergoline alkaloids from a plant-associated fungus, 12 endophytic fungi and one epibiotic fungus were isolated from an ergoline alkaloid-containing Convolvulaceae plant, Ipomoea asarifolia Roem. & Schult. Phylogenetic trees constructed from 18S rDNA genes as well as internal transcribed spacer (ITS) revealed that the epibiotic fungus belongs to the family Clavicipitaceae (Ascomycota) whereas none of the endophytic fungi does. In vitro and in vivo cultivation on intact plants gave no evidence that the endophytic fungi are responsible for the accumulation of ergoline alkaloids in I. asarifolia whereas the epibiotic clavicipitaceous fungus very likely is equipped with the genetic material to synthesize these compounds. This fungus resisted in vitro and in vivo cultivation and is seed transmitted. Several observations strongly indicate that this plant-associated fungus and its hitherto unidentified relatives occurring on different Convolvulaceae plants are responsible for the isolated occurrence of ergoline alkaloids in Convolvulaceae. This is the first report of an ergot alkaloid producing clavicipitaceous fungus associated with a dicotyledonous plant.
Steiner
Ulrike
U
Institut für Pflanzenkrankheiten der Universität Bonn, Nussallee 9, 53115 Bonn, Germany.
Ahimsa-Müller
Mahalia A
MA
Markert
Anne
A
Kucht
Sabine
S
Gross
Julia
J
Kauf
Nicole
N
Kuzma
Monika
M
Zych
Monika
M
Lamshöft
Marc
M
Furmanowa
Miroslawa
M
Knoop
Volker
V
Drewke
Christel
C
Leistner
Eckhard
E
D001203:Ascomycota / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D021901:DNA, Intergenic / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D004876:Ergot Alkaloids / Q000096:biosynthesis* / Q000737:chemistry; D005800:Genes, Fungal; D027741:Ipomoea / Q000196:embryology / Q000378:metabolism / Q000382:microbiology*; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology / Q000648:ultrastructure; D017368:Protein Prenylation; D012639:Seeds / Q000382:microbiology*; D014364:Tryptophan / Q000378:metabolism
D021901:DNA, Intergenic; D004275:DNA, Ribosomal; D004876:Ergot Alkaloids; D014364:Tryptophan