The role of macrosporin in necrotic spots

Macrosporin, a bioactive metabolite produced by a plant-pathogenic fungus Stemphylium lycopersici , was found to be a non-host selective toxin which plays a part in leaf necrosis, a disease caused by this fungus. Here, we discuss the role of this metabolite in necrotic spots, through the direct inoculation of the midribs of the leaves of a natural host, as well as its ability to generate active oxygen species, through the process of photosensitizing oxygen.