Characterization of Hypersensitive Response Related Genes of Arabidopsis thaliana

Like most complex living organisms, plants have many mechanisms to prevent disease by microbial pathogens. One of the most important and well developed defense systems that involve recognition, identification and systematic response is the hypersensitive response. The hypersensitive response is a complex, early defense response against pathogens that causes necrosis and cell death at the site of infection to restrict the spread of pathogen. Hypersensitive response is a type of programmed cell death, and its activation usually happens when the plant recognizes a pathogen through an elicitor. This recognition triggers a series of signal transductions events which end in the expression of several defense-associated genes. The result of those responses causes death of plant cells and the formation of local lesions, creating barriers and hostile environment to inhibit the spread of infection. The work in our laboratory has identified several hundred Arabidopsis genes that are differentially expressed in response to pathogen infection. In addition to regulating defense against pathogens, some of these genes are likely to be involved in regulating other plant physiological processes. To determine the role of these genes in regulating defense against pathogens and other biotic and abiotic stresses, I have analyzed responses to knockout mutants of several of these genes to a variety of biotic and abiotic stresses. My results suggest that many of the pathogen defence-related genes are also involved in regulating other biotic and abiotic stresses