Volatile Organic Compounds in the Azteca/Cecropia Ant-Plant Symbiosis and the Role of Black Fungi

Author(s)
Veronika E. Mayer, Sybren de Hoog, Simona M. Cristescu, Luciano Vera, Francesc X. Prenafeta-Boldú
Abstract

Black fungi of the order Chaetothyriales are grown by many tropical plant-mutualistic ants as small so-called “patches” in their nests, which are located inside hollow structures provided by the host plant (“domatia”). These fungi are introduced and fostered by the ants, indicating that they are important for the colony. As several species of Chaetothyriales tolerate, adsorb, and metabolize toxic volatiles, we investigated the composition of volatile organic compounds (VOCs) of selected domatia in the Azteca/Cecropia ant-plant mutualism. Concentrations of VOCs in ant-inhabited domatia, empty domatia, and background air were compared. In total, 211 compounds belonging to 19 chemical families were identified. Ant-inhabited domatia were dominated by ketones with 2-heptanone, a well-known ant alarm semiochemical, as the most abundant volatile. Empty domatia were characterized by relatively high concentrations of the monoterpenes d-limonene, p-cymene and β-phellandrene, as well as the heterocyclic sulphur-containing compound, benzothiazole. These compounds have biocidal properties and are primarily biosynthesized by plants as a defense mechanism. Interestingly, most of the latter compounds were present at lower concentrations in ant inhabited domatia than in non-colonized ones. We suggest that Chaetothyriales may play a role in reducing the VOCs, underlining that the mutualistic nature of these fungi as VOCs accumulation might be detrimental for the ants, especially the larvae.

Organisation(s)
Department of Botany and Biodiversity Research
External organisation(s)
Radboud University, Olafsense GmbH, Institut de Recerca I Tecnologia Agroalimentàries
Journal
Journal of Fungi
Volume
7
ISSN
2309-608X
DOI
https://doi.org/10.3390/jof7100836
Publication date
2021
Peer reviewed
Yes
Austrian Fields of Science 2012
106042 Systematic botany, 106008 Botany, 106012 Evolutionary research
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/volatile-organic-compounds-in-the-aztecacecropia-antplant-symbiosis-and-the-role-of-black-fungi(3b9b6d1b-0577-493e-9c70-fb6c9362143a).html