In the course of its evolution, plants have developed various mechanisms that act on the local and systemic levels and which role is to adapt plants to the environment they live in. One of these mechanisms is widely recognized plant defense system directed against biotic factors, to which belongs, among the others, pathogen attack.

The discovery of a number of important points signaling pathways in studies of plant response to biotic stress was made possible by the use of mutants of the model plant Arabidopsis thaliana. The availability of mutants, a knock-out, obtained by chemical mutagenesis or insertion mutants line allows you to focus on a specific issue without the time-consuming research to create their own mutants.