Plant Defense Gene Expression and Physiological Response

The perception of the pathogen signal by the host specific receptors and its transduction by various signaling pathways culminate in the synthesis and synchronized accumulation of defensive molecules some of which play a structural role while others exercise a direct antimicrobial function. Biochemical mechanisms include, among others, the synthesis of peptides and antimicrobial proteins, hydrolytic enzymes as well as the production of phytoalexins and secondary metabolites with high antimicrobial potential. This chapter provides a synthesis of the remarkable progress made in recent years in terms of understanding the mechanisms applied in the molecular and physiological alterations that occur during the defense response of plants.

Keywords: Defensins, Hypersensible response (HR), Protease inhibitors, Phytoalexins, Pathogenesis-related proteins (PRs), Secondary metabolites.