Descrição e caracterização de novas espécies amazônicas de Trichoderma com aplicações na agricultura e biotecnologia

Abstract

The genus Trichoderma is widely recognized for its crucial role in modern agriculture due to its ability to promote plant growth and control diseases in a sustainable and ecological manner. With more than 500 valid species described, the growing number of genomic sequences has revealed a vast repertoire of enzymes and metabolites with great biotechnological potential. In this thesis, different taxonomic, functional, and genomic approaches were applied to characterize Trichoderma strains isolated from Amazonian environments, resulting in the description of new species and the identification of relevant bioactive compounds. In the first study, a new species, Trichoderma agriamazonicum, was isolated and characterized from Scleronema micranthum (Malvaceae). The identification was based on morphological and phylogenetic analyses, which were corroborated by functional studies demonstrating the fungus's ability to inhibit the growth of various phytopathogens through mycoparasitism and the production of volatile organic compounds (VOCs). In vivo assays on Capsicum chinense fruits showed effective control of rot caused by Colletotrichum scovillei. Chemical and genomic analyses revealed the production of novel metabolites and the presence of numerous biosynthetic clusters, highlighting the biotechnological potential of the new species. In the second study, 43 Trichoderma strains isolated from Amazonian river sediments were characterized. Phylogenetic analysis based on the tef1-α gene identified 15 species, including the description of five new species and the first report of two species in Brazil. In vitro antagonism assays demonstrated the potential of several strains as biocontrol agents, a result validated by in vivo tests on cowpea seeds. Genome mining of these strains revealed a diversity of biosynthetic clusters associated with the production of antifungal, antibacterial, and cytotoxic metabolites. The results obtained highlight the richness of Trichoderma biodiversity in the Amazon and reinforce the potential of these new species as sources of biocontrol agents and bioactive compounds, contributing to the development of sustainable agricultural alternatives and future biotechnological applications.