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| Author(s): |
Karina Bueno de Oliveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Rio Claro. 2020-07-29. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro |
| Defense date: | 2020-02-28 |
| Advisor: | André Rodrigues; Paulo Cezar Vieira |
| Abstract | |
The fungus garden of attine ants harbors a diverse microbiota, whose members interact by chemical compounds. Although studies unraveled the metabolites produced by fungi cultivated (Leucoagaricus spp.) by these insects, little is known regarding the chemical compounds involved in the interaction with Escovopsis sp., a fungus known as a parasite of the ant fungal cultivars. Here, we investigated the metabolites produced by three mutualistic fungi cultivated by different attine ants to answer the following questions: a) Do the metabolites produced by the mutualistic fungi mediate the interaction with Escovopsis sp.?; b) Do the day of growth and the concentration of the metabolites interfere in the Escovopsis sp. response?; c) Are soluble and volatile compounds involved in this interaction? We addressed these questions by carrying out bioassays: (i) with culture filtrates of the three mutualistic fungi at two concentrations (1:1 and 1:10), obtained on different days of incubation; (ii) with the organic fraction and subfractions of these filtrates towards Escovopsis sp.; (iii) to determine volatile compounds are involved in the interaction; in addition to (iv) the chemical study of the organic fractions and subfractions. We demonstrated that the interaction between Escovopsis sp. and the mutualistic fungi of attine ants is mediated by soluble and volatile compounds, since we observed a maximization of the parasite's growth in the presence of both the mutualistic fungal culture filtrates, their fractions and subfractions, as well as in the volatility experiments. Also, we identified two substances from the class of diketopiperazines and the 5-hydroxymethylfurfural (subfractions Ϭ3 e Ϭ5). The diketopiperazine Ϭ5 and the 5-hydroxymethylfurfural act as signaling agents involved in the interaction Escovopsis sp. and the mutualistic fungus, because the parasite maximizes its growth in the presence of these substances. Such compounds were obtained from culture filtrates of the 12th day of growth of Leucoagaricus sp. AR04. However, the maximized growth response of the parasite did not depend on the growth phases of mutualistic fungi, because this response was observed in culture filtrates obtained on all days of cultivation of the mutualistic fungi. The ancient evolutionary history shared between these two fungi is likely responsible for the complexity of this chemical interaction, especially the ability of Escovopsis sp. to recognize the compounds produced by the ant fungal cultivars. (AU) | |
| FAPESP's process: | 18/12481-7 - Metabolomics of the fungus cultivated by the ants and consequent attraction of the parasite Escovopsis |
| Grantee: | Karina Bueno de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Master |