Elimination of ergoline alkaloids following treatment of Ipomoea asarifolia (Convolvulaceae) with fungicides

Abstract

Ergoline alkaloids are constituents of Clavicipitaceous fungi living on Poaceae plants. Ergoline alkaloids as well as volatile oil are also present in Ipomoea asarifolia Roem. & Schult (Convolvulaceae). Treatment of this plant with two fungicides (Folicur, Pronto Plus) eliminates the ergoline alkaloids but not the volatile oil. Elimination of ergoline alkaloids occurs concomitantly with loss of fungal hyphae associated with secretory glands on the upper leaf surface of the Ipomoea plant. Our observations suggest that accumulation of ergoline alkaloids in the Convolvulaceae may depend on the presence of a plant-associated fungus.

Biosynthesis and Accumulation of Ergoline Alkaloids in a Mutualistic Association between Ipomoea asarifolia (Convolvulaceae) and a Clavicipitalean Fungus

“…It is in line with these observations that Ipomoea asarifolia and related plant species belonging to the family Convolvulaceae are associated with a clavicipitalean fungus and contain ergoline alkaloids (Kucht et al, 2004;Steiner et al, 2006;Ahimsa-Mueller et al, 2007). Treatments of I. asarifolia (white blooming variety) and Turbina corymbosa (syn.…”

“…Because the dmaW gene was found to be part of a cluster responsible for ergoline alkaloid biosynthesis in clavicipitalean fungi (compare Haarmann et al, 2005Haarmann et al, , 2006Fleetwood et al, 2007), the genetic material on the chromosome adjacent to this gene was also analyzed. We have previously demonstrated (Kucht et al, 2004) that alkaloids and the clavicipitalean fungi can be removed from I. asarifolia and T. corymbosa by treatment of the plant with systemic azole fungicides. Shoots of these plants rooted in garden soil grew into well-developed plants within a few weeks.…”

“…These observations indicate that the disjointed occurrence of ergoline alkaloids in nature is not due to a horizontal gene transfer that might have happened during evolution, but it has been shown (Kucht et al, 2004;Steiner et al, 2006;Ahimsa-Mueller et al, 2007) that ergoline alkaloid-producing clavicipitalean fungi do not only colonize monocotyledonous plants like grasses (compare books and reviews listed above), but also dicotyledonous plants such as Convolvulaceae.…”

“…Treatments of I. asarifolia (white blooming variety) and Turbina corymbosa (syn. Rivea corymbosa) with fungicides leads to the removal of epibiotic fungi and concomitant loss of ergoline alkaloids from the plants (Kucht et al, 2004). Sequencing of the nuclear ribosomal 18S rDNA and internal transcribed spacer showed that these fungi are members of the family Clavicipitaceae (Steiner et al, 2006;Ahimsa-Mueller et al, 2007).…”

Elimination of the tremorgenic toxin of Ipomoea asarifolia by milk

“…Research has shown that a clavicipitaceous epibiotic fungal symbiont, Periglandula, is associated with the Convolvulaceae that produce ergot alkaloids including I. asarifolia (Kucht et al 2004, Markert et al 2008, Steiner et al 2011). More recently, it was shown that I. asarifolia contains the indole--diterpenes and that the Periglandula species associated with it contains the biosynthetic genes for both the ergot alkaloids as well as the indole diterpenes (Schardl et al 2013).…”