The role of plant hormones in Fusarium Head Blight of wheat

Fusarium Head Blight (FHB) is a devastating disease of cereals caused by a group of trichothecene-producing fungi belonging to the Fusarium genus. In plant-pathogen interactions, hormones (salicylic acid, jasmonic acid and ethylene) modulate a series of defence responses, including expression of pathogenesis-related (PR) genes, which limit pathogen spread or obliterates it entirely. The gene expression data from three wheat genotypes presented in this thesis suggests that PR gene regulation by plant hormones may be genotype-dependent in wheat. Exogenous application of ethylene activators/inhibitors in six wheat genotypes with different level of resistance to FHB showed that ET plays a positive role in the resistance response. A similar response was observed in Fusarium seedling blight (FSB) disease assays, where exogenous chemical treatments showed that ethylene is involved in a resistance response. In addition, SA was shown to play a positive role in resistance to FSB, while MeJA increased susceptibility