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

Author(s)

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

Abstract

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.

Organisation(s)

Functional and Evolutionary Ecology, Large-Instrument Facility for Environmental and Isotope Mass Spectrometry, Department of Microbiology and Ecosystem Science, Department of Botany and Biodiversity Research

External organisation(s)

Technische Universität Wien, University of Natural Resources and Life Sciences, Carl von Ossietzky Universität Oldenburg, Smithsonian Tropical Research Institute

Journal

New Phytologist

Volume

238

Pages

2210-2223

No. of pages

14

ISSN

0028-646X

DOI

https://doi.org/10.1111/nph.18761

Publication date

2023

Peer reviewed

Yes

Austrian Fields of Science 2012

106008 Botany, 106024 Mycology, 106030 Plant ecology, 106054 Zoology

Keywords

ASJC Scopus subject areas

Physiology, Plant Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/797375e1-e247-4a55-bd03-7ba788ad0d8d