Exo- and endophytic fungi enable rapid transfer of nutrients from ant waste to orchid tissue

Christian Gegenbauer, Anke Bellaire, Arno Schintlmeister, Markus C Schmid, Markus Kubicek, Hermann Voglmayr, Gerhard Zotz, Andreas Richter, Veronika Mayer

The epiphytic orchid Caularthron bilamellatum sacrifices its water storage tissue for nutrients from the waste of ants lodging inside its hollow pseudobulb. Here, we investigate whether fungi are involved in the rapid translocation of nutrients. Uptake was analysed with a

15N labelling experiment, subsequent isotope ratio mass spectrometry (IRMS) and secondary ion mass spectrometry (ToF-SIMS and NanoSIMS). We encountered two hyphae types: a thick melanized type assigned to ‘black fungi’ (Chaetothyriales, Cladosporiales, and Mycosphaerellales) in ant waste, and a thin endophytic type belonging to Hypocreales. In few cell layers, both hyphae types co-occurred.

15N accumulation in both hyphae types was conspicuous, while for translocation to the vessels only Hypocreales were involved. There is evidence that the occurrence of the two hyphae types results in a synergism in terms of nutrient uptake. Our study provides the first evidence that a pseudobulb (=stem)-born endophytic network of Hypocreales is involved in the rapid translocation of nitrogen from insect-derived waste to the vegetative and reproductive tissue of the host orchid. For C. bilamellatum that has no contact with the soil, ant waste in the hollow pseudobulbs serves as equivalent to soil in terms of nutrient sources.

Department für Funktionelle und Evolutionäre Ökologie, Institut für Anorganische Chemie, Department für Mikrobiologie und Ökosystemforschung, Großgeräteeinrichtung für Umwelt- und Isotopen-Massenspektrometrie, Department für Botanik und Biodiversitätsforschung, Institut für Analytische Chemie
Externe Organisation(en)
Technische Universität Wien, Universität für Bodenkultur Wien, Carl von Ossietzky Universität Oldenburg, Smithsonian Tropical Research Institute
New Phytologist
ÖFOS 2012
106008 Botanik, 106024 Mykologie, 106030 Pflanzenökologie, 106054 Zoologie
ASJC Scopus Sachgebiete
Physiology, Plant Science
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