Exploring novel regulators and enzymes in salicylic acid-mediated plant defense

Salicylic acid (SA) is a plant hormone, which is involved in the defense responses to pathogens and to abiotic stress, and in the regulation of plant growth and development. The shikimate pathway end product chorismic acid serves as the precursor for salicylic acid. In the model plant Arabidopsis thaliana. Chorismate is converted to salicylic acid by a chloroplast-localized isochorismate synthase and an unidentified isochorismate pyruvate lyase. EDS5, a member of the multidrug and toxin extrusion (MATE) transporter family, localized in the chloroplast envelope is responsible for SA transport from the chloroplasts to the cytosol. SA triggers a local defense response as well as a systemic defense response through the whole plant. The first objective in this thesis focused on transcription factors for the regulation of EDS5 gene expression. The second objective was to identify the missing enzyme with isochorismate pyruvate lyase activity.Plant science