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| Author(s): |
Bruna Cristina Custodio
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Rio Claro. 2019-04-11. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro |
| Defense date: | 2019-02-25 |
| Advisor: | André Rodrigues; Priscila Cintra Socolowski |
| Abstract | |
In parasite-host interactions it is expected from the former to rely mostly on nutrients derived from the host. Attine ant colonies may be considered as a model system for studying different mechanisms of parasitism. These insects cultivate a basidiomycetous fungus, which is threatened by mycoparasites in the genus Escovopsis. It is known that the fungus garden, the substrate where the ants cultivate the fungal cultivar, has a high concentration of simple carbon sources. Here we investigated whether the parasite benefits from these nutritional resources and whether these nutrients influence host infectivity. We performed bioassays to evaluate the development of six Escovopsis isolates in different carbon sources in the absence as well as in the presence of the ant fungal cultivar. In addition, we observed the interaction Escovopsis – fungal cultivar with epifluorescence microscopy, to assess when the degradation of the host mycelium begins. Overall, the parasite showed sporulation below 59 % when only one carbon source was available. When interacting with their hosts in culture medium with one or two carbon sources, three out of six Escovopsis isolates were less infective than expected, probably due to nutritional stress. We observed that the parasite’s infectivity did not increase with the addition of one nutritional source, however, influenced its growth, even in the presence of the host (the expected primary source of nutrition). Our results suggest that in addition to the host mycelium, Escovopsis may use additional sources of nutrients present in the fungus garden for its development. Analysis with epifluorescence microscopy evidenced that the mycelial degradation of the host initiates before the establishment of physical contact between hyphae, suggesting that metabolites produced by Escovopsis are involved. (AU) | |
| FAPESP's process: | 17/08931-4 - Nutrition and parasitism in the fungal genus Escovopsis |
| Grantee: | Bruna Cristina Custodio |
| Support Opportunities: | Scholarships in Brazil - Master |