Prelecionista: Sara Salcedo Sarmiento (10/4/2018, 16h, auditório ESB). Orientador: Prof. Robert Barreto. Resumo: Coffee has great economic and social relevance worldwide, and is one of the major traded commodities in the world, with Brazil as the largest producer and exporter. Coffee leaf rust (CLR) caused by the biotrophic fungus Hemileia vastatrix is the most important disease of the crop, reducing production by up to 30-50%. The disease is widely distributed in all the countries where coffee is grown in the world. The main damage caused by coffee rust is defoliation. Occasionally branch and even plant death may occur. CLR control has been based on the use of resistant varieties, escaping the disease through highland plantation and the use of fungicides. However each of these approaches have been challenged by obstacles posed by climate change, resistance breakdown, costs of fungicide applications and the growing market demand for pesticide free products. Biological control remains a marginal and mostly experimental alternative.  Exploitations for antagonistic microbes and scientific publications dealing with their application in CLR control are few. Here, results of the investigations on four selected fungal species collected in association with uredinia of H. vastatrix in Brazil are presented. Their identity was elucidated and in vitro and in planta  tests studies have indicated the biocontrol of two species. The alterations induced by the antagonistic fungi were analyzed by histochemical, photosynthetic and epidemiological analysis of coffee plants treated and untreated with the antagonists. Results will be discussed. They contribute to the understanding of the interaction between antagonistic fungi and their fungal hosts, and can contribute to the development of strategies for the biological control of coffee rust.