Ferramentas biotecnológicas na interação planta-patógeno: filogenia multilocus e genômica funcional na caracterização de Colletotrichum falcatum em saccharum spp. e de quitinases em Coffea spp.

Abstract

Fungal diseases cause significant agricultural losses, directly impacting economically important crops such as sugarcane (Saccharum spp.) and coffee (Coffea spp.). Inadequate pathogen identification and limited understanding of plant defense mechanisms represent major obstacles to the implementation of more effective disease management strategies. This thesis aimed to investigate the molecular aspects of the plant-pathogen interaction by integrating plant biotechnology tools applied to two distinct pathosystems. In the first study, isolates of Colletotrichum falcatum associated with red rot of sugarcane in southern Florida were characterized through multilocus phylogenetic analysis, microscopy, and pathogenicity tests. This approach allowed for the confirmation of the pathogen's identity, the description of events in the infectious process, and the assessment of the virulence of the isolates in commercial varieties. The second study conducted a comprehensive genomic characterization of chitinase genes and proteins in Coffea arabica and its progenitors (C. canephora and C. eugenioides). In silico analyses were employed, including phylogenetic analyses, functional domain prediction, gene structure, subcellular localization, and identification of orthologs, allowing for the identification of candidate genes potentially involved in resistance to fungal diseases. The results highlight the potential of molecular and genomic approaches to enhance the understanding of fungal pathogenicity and plant defense mechanisms. This thesis demonstrates how biotechnology can support the development of more targeted disease management strategies and inform breeding programs for crops of agricultural importance.