Cereal diseases caused by Fusarium graminearum: from biology of the pathogen to oxidative burst-related host defense responses

Fusarium graminearum Schwabe (teleomorph: Gibberella zeae ) is a destructive fungus, causing economically important diseases such as seedling blight, root and crown rot and head blight on small grain cereals, in particular wheat and barley. It is a devastating phytopathogen, not only due to causing significant yield losses, but also because of contaminating plant tissues with trichothecenes and other types of mycotoxins, which are harmful for human animal health. Several disease management strategies are used to decrease yield losses and mycotoxin production in cereals caused by this pathogenic fungus. Among various disease control methods, use of resistant cultivars could be the most effective way to combat diseases caused by F. graminearum in cereals. However, any plant cultivar with complete resistance against this pathogen was not reported worldwide and only some of the host cultivars with partial resistance against F. graminearum were identified, so far. Therefore, understanding biochemical and cytomolecular aspects of interaction in F. graminearum -cereals pathosystems would be valuable for designing novel management strategies against various diseases caused by this hemibiotrophic fungal pathogen on economically important cereals. This review is focused on biology, pathogenicity, and genetic structure of F. graminearum populations together with the role of reactive oxygen species (ROS) and antioxidant systems in association with plant cell wall in defense responses of cereals, as the main resistance mechanisms against this destructive fungus.