Prelecionista: Thiago Moura Rocha
Orientador: Lucas Magalhães de Abreu
Data: 29/04/2025, às 16
Local: Anfiteatro do DFP – ESB

Resumo: The collective behavior mechanism known as quorum sensing (QS) has been extensively studied and is well established in bacteria. It typically requires high cell density, a diffusible signaling molecule, and a membrane-bound receptor for activation. Several phytopathogenic bacteria utilize QS to facilitate infection and disease progression in host plants, promoting biofilm formation, effector secretion, and plasmid conjugation. In eukaryotes, QS has been investigated in the model organism Dictyostelium discoideum and, more recently, in fungi such as the human pathogen Candida albicans. In these organisms, QS activation triggers key developmental changes, including a transition from the vegetative to the reproductive phase in D. discoideum and a morphogenetic switch in C. albicans. The first evidence of QS mechanisms in phytopathogenic fungi emerged later, with the identification of QS in the Dutch elm disease agents Ophiostoma ulmi and O. novo-ulmi. This was followed by discoveries in Aspergillus flavus and the sap-staining fungus Ophiostoma piceae. In A. flavus, QS regulates the phase shift by modulating the conidia-to-sclerotia ratio and influencing aflatoxin production. In the dimorphic fungi O. ulmi, O. novo-ulmi, and O. piceae, QS activation induces morphological changes, such as transitions between yeast and hyphal forms. Herein, we aimed to explore the molecular mechanisms underlying QS signal transduction and its involvement in the pathogenicity of these fungi. To this end, we analyzed studies that investigated key components of QS pathways, including the biosynthesis, secretion, and perception of signaling molecules, as well as downstream regulatory cascades. By integrating genomic, transcriptomic, and biochemical data, these studies identified both conserved and species-specific elements that mediate QS responses.