Escovopsioides nivea (Ascomycota: Hypocreales): antagonista de fungos cultivados pelas formigas atíneas
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Data
2022-04-01
Autores
Pietrobon, Tatiane de Castro [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Interações entre organismos são comuns na natureza e responsáveis por manter o equilíbrio dos ecossistemas. O mutualismo entre as formigas atíneas e fungos é um exemplo clássico de simbiose. Esses insetos cultivam o parceiro fúngico como fonte de alimento, e este recebe proteção, além de ser disperso pelas formigas. Ambos os organismos co-evoluíram levando à formação de cinco diferentes tipos de fungiculturas. Um antagonista alvo de estudo desse sistema é o fungo do gênero Escovopsis, considerado parasita do fungo cultivado pelas formigas. Estudos revelaram que esse fungo coevoluiu com o sistema e que o parasitismo é mediado por substâncias químicas. Fungos do gênero Escovopsioides, filogeneticamente relacionados a Escovopsis, também são encontrados nas colônias das formigas atíneas. Escovopsioides é um possível antagonista do fungo mutualista das atíneas, entretanto, pouco se conhece sobre a diversidade filogenética e o real papel desse fungo no ambiente das formigas atíneas. Os objetivos do presente estudo foram descrever a diversidade e o papel de Escovopsioides na interação das formigas atíneas com o fungo cultivado. Como poucos isolados desse fungo são conhecidos, ampliamos as amostragens desse gênero com coletas de jardins de fungo de formigas atíneas em diferentes localidades do país. Os isolados obtidos foram identificados por sequenciamento genético. Nosso estudo sugere que apenas uma espécie de Escovopsioides, E. nivea, está associada ao ambiente das formigas atíneas como um simbionte. Em seguida, bioensaios de co-cultivo foram realizados entre E. nivea e os fungos mutualistas de quatro, dentre cinco, diferentes tipos de fungiculturas das formigas atíneas. Bioensaios semelhantes foram utilizados para analisar os metabólitos envolvidos nessas interações. Nossos resultados demonstraram que E. nivea é um antagonista, pois inibe o crescimento de diversos fungos cultivados pelas atíneas. É possível metabólitos difundidos no meio de cultivo sejam os responsáveis pelo antagonismo observado, entretanto, outros fatores também podem estar envolvidos, como substâncias voláteis e/ou competição por nutrientes.
Interactions between organisms are common in nature and play an important role in ecosystem maintenance. The mutualism between attine ants and fungi is a textbook example of a mutualistic symbiosis. These insects cultivate their fungal partner for food and in turn they provide the fungus protection, growth substrate, and the means of dispersal. Both organisms coevolved in an association that led to five fungiculture types. A known antagonist of this system is the fungal genus Escovopsis, often considered a parasite of the attine fungal cultivars. This fungus co-evolved with the system and this interaction is mediated by metabolites. Fungi in the genus Escovopsioides are phylogenetically close-related to Escovopsis and are also found in colonies of attine ants. Escovopsioides is a possible antagonist of the fungal cultivars, however, little is known about the phylogenetic diversity and its role in the attine ant environment. Here, we describe the diversity and ecological role of Escovopsioides within the attine ant-fungal mutualism. We carried out collections of fungus gardens of attine ants to expand the sampling of the genus. These obtained isolates were identified by DNA sequencing. Our study suggests that only one Escovopsioides species, E. nivea, is associated with the attine ant environment as a symbiont. Then, dual-culture bioassays were performed between E. nivea and the mutualistic fungi of four out of five different fungicultural types of the attine ants. Similar bioassays were used to analyze the metabolites involved in these interactions. Our findings showed that E. nivea inhibits the growth of several fungi cultivated by attines and can, therefore, be considered an antagonist. Our results also suggest the antagonism may occur by metabolites diffused in the culture medium, but other factors may also be involved, such as volatile compounds and/or competition for nutrients by this fungus.
Interactions between organisms are common in nature and play an important role in ecosystem maintenance. The mutualism between attine ants and fungi is a textbook example of a mutualistic symbiosis. These insects cultivate their fungal partner for food and in turn they provide the fungus protection, growth substrate, and the means of dispersal. Both organisms coevolved in an association that led to five fungiculture types. A known antagonist of this system is the fungal genus Escovopsis, often considered a parasite of the attine fungal cultivars. This fungus co-evolved with the system and this interaction is mediated by metabolites. Fungi in the genus Escovopsioides are phylogenetically close-related to Escovopsis and are also found in colonies of attine ants. Escovopsioides is a possible antagonist of the fungal cultivars, however, little is known about the phylogenetic diversity and its role in the attine ant environment. Here, we describe the diversity and ecological role of Escovopsioides within the attine ant-fungal mutualism. We carried out collections of fungus gardens of attine ants to expand the sampling of the genus. These obtained isolates were identified by DNA sequencing. Our study suggests that only one Escovopsioides species, E. nivea, is associated with the attine ant environment as a symbiont. Then, dual-culture bioassays were performed between E. nivea and the mutualistic fungi of four out of five different fungicultural types of the attine ants. Similar bioassays were used to analyze the metabolites involved in these interactions. Our findings showed that E. nivea inhibits the growth of several fungi cultivated by attines and can, therefore, be considered an antagonist. Our results also suggest the antagonism may occur by metabolites diffused in the culture medium, but other factors may also be involved, such as volatile compounds and/or competition for nutrients by this fungus.
Descrição
Palavras-chave
Symbiosis, Fungal-fungal interaction, Diversity, Inhibition, Simbiose, Interação fungo-fungo, Diversidade, Inibição