The diversity of ant-associated black yeasts: insights into a newly discovered world of symbiotic interactions

Author(s)
Hermann Voglmayr, Veronika Mayer, Ulrich Maschwitz, Joachim Moog, Champlain Djieto-Lordon, Rumsais Blatrix
Abstract

Based on pure culture studies and DNA phylogenetic analyses, black yeasts (Chaetothyriales, Ascomycota) are shown to be widely distributed and important components of numerous plant ant fungus networks, independently acquired by several ant lineages in the Old and New World. Data from ITS and LSU nu rDNA demonstrate that a high biodiversity of fungal species is involved. There are two common ant fungus symbioses involving black yeasts: (1) on the carton walls of ant nests and galleries, and (2) the fungal mats growing within non-pathogenic naturally hollow structures (so-called domatia) provided by myrmecophytic plants as nesting space for ants (ant plant symbiosis). Most carton- and domatia-inhabiting fungi stem from different phylogenetic lineages within Chaetothyriales, and almost all of the fungi isolated are still undescribed. Despite being closely related, carton and domatia fungi are shown to differ markedly in their morphology and ecology, indicating that they play different roles in these associations. The carton fungi appear to improve the stability of the carton, and several species are commonly observed to co-occur on the same carton. Carton fungi commonly have dark-walled monilioid hyphae, colouring the carton blackish and apparently preventing other fungi from invading the carton. Despite the simultaneous presence of usually several species of fungi, forming complex associations on the carton, little overlap is observed between carton fungi from different ant species, even those that co-occur in nature, indicating at least some host specificity of fungi. Most fungi present on carton belong to Chaetothyriales, but in a few samples, Capnodiales are also an important component. Carton fungi are difficult to assign to anamorph genera, as most lack conidiation. The domatia fungi are more specific. In domatia, usually only one or two fungal species co-occur, producing a dense layer on living host plant tissue in domatia. They have hyaline or light brown thin-walled hyphae, and are commonly sporulating. In both carton and domatia, the fungal, species seem to be specific to each ant plant symbiosis Representative examples of carton and domatia ant fungus symbioses are illustrated. We discuss hypotheses on the ecological significance of the Chaetothyriales associated with ants.

Organisation(s)
External organisation(s)
Johann Wolfgang Goethe-Universität Frankfurt am Main, Université de Yaoundé I, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), CNRS-UMR 5175
Journal
Fungal Biology
Volume
115
Pages
1077-1091
No. of pages
15
ISSN
1878-6146
DOI
https://doi.org/10.1016/j.funbio.2010.11.006
Publication date
2011
Peer reviewed
Yes
Austrian Fields of Science 2012
106024 Mycology
Portal url
https://ucris.univie.ac.at/portal/en/publications/the-diversity-of-antassociated-black-yeasts-insights-into-a-newly-discovered-world-of-symbiotic-interactions(a3b8d322-78e2-40e0-9296-31ee78d6e47f).html