Nutrition and parasitism in the fungal genus Escovopsis

Abstract

Ants in tribe Attini cultivate fungi for food, establishing a mutualistic relationship with their partner. These insects develop the fungiculture in the fungus gardens. It is known that fungus garden have high concentrations of simple sugars, resultant of degradation the plant substrate by the ants' mutualistic fungi. The genus Escovopsis comprises fungi considered mycoparasites of the ants' fungal cultivars. Although previous works have explored several aspects of this parasite-host interaction, the nutritional mechanisms of Escovopsis are still poorly known. Here, we aim to investigate whether Escovopsis benefits from the sugars present in the fungus garden matrix and if these nutrients influence the infectivity towards its host. We will perform in vitro bioassays to evaluate the assimilation of different carbon sources by Escovopsis in the presence and absence of the host. In addition, we intent to observe the parasite-host interaction using confocal laser scanning microscopy applying specific fluorescent dyes to examine cellular viability and cell wall integrity. We hope to understand the mechanisms which Escovopsis parasitize its host. Our goal is to determine whether the host degradation is initiated either before or after the physical contact with Escovopsis hyphae. The approach and techniques we intent to use have never been employed in this parasite-host system. Thus, the present study will gather original information to fill the gaps about the biology of this important parasitic fungus. Such knowledge will boost the research using this fungus as a biological control agent. (AU)