Plant ability to cope with environmental stresses is essential for their survival. Following infection by pathogenic micro-organisms, plants rapidly activate local and systemic response leading to the synthesis of several antimicrobial molecules. Among them are antifungal proteins collectively known as “Pathogenesis Related (PR) proteins. The wide-ranging modes of action of PR proteins make them an ideal tool in defence strategies against “all comers”. In fact, in some cases overexpression of some PR genes has been shown to provide protection against several pathogen. This holds promises for the development of new strategies complementing conventional breeding programs to produce more resistant cultivars, thus meeting both the growing concern about the environment and the strong motivation to lower production costs. However, it is timely to highlight that overexpression of PR genes has been mainly obtained using the 35S cauliflower mosaic virus (CaMV) promoter, which confers constitutive expression of the transgene. A worthwhile research objective will involve the use of inducible and/or tissue-specific promoters that will allow expression of transgenic PR proteins only when needed and only in the desired tissues.Structural-functional characterization of wheat PR proteins and genes is only at the beginning and represents an interesting research area due to the relevance of this cereal for nutrition. The main aim of this research unit is to study in depth the mode of action of wheat PR-4 proteins and genes as well as the mechanism of antifungal activity towards pathogenic fungi and oomyces. Moreover, the isolation of genomic clones encoding these proteins will allow the study of PR4 gene organization and expression besides the identification of regulatory elements through traditional promoter deletion analysis coupled with mutagenesis of functional domain. Finally, recombinant vectors will be constructed carrying GUS (or GFP) reporter gene under control of wheat PR-4 promoter and used in expression analysis in transgenic plants challenged with different biotic and abiotic inducers.