Palestrante: Dra. Patricia Ricardino da Silveira. Data: 19/03/2019, às 16:00 horas no Anfiteatro do ESB. Pathogens cause substantial modifications to host physiology, which can occur directly via the secretion of lytic enzymes and toxins or indirectly via host responses induced by the pathogen. Among the relevant physiological processes, photosynthesis is the one primarily affected by foliar diseases. Reductions in photosynthesis may be proportional to decreases in green leafy tissue, or they may be greater or less than would be expected if the reduction were related to disease severity alone. Both diffusive and biochemical factors have been invoked as prime causes associated with impaired photosynthesis in diseased leaves. Fungal infection can also affect the net carbon assimilation rate by increasing leaf respiration, which is necessary for supplying the demand caused by the accelerated metabolic activity of the host cells. In any case, despite many efforts to elucidate the mechanisms by which pathogens are capable of affecting photosynthetic capacity, actual knowledge of the subject remains far from comprehensive. This seminar will focus on how pathogens of different lifestyles impair the photosynthesis on their host and the techniques currently used to detect the changes involved.