Investigation of defence mechanisms against Botrytis cinerea in Arabidopsis thaliana

Includes bibliographical references (leaves 63-86).Disease resistance in plants has been extensively studied for the past century with many new and exciting results being discovered each year. A plant utilises both preformed and induced defence responses to resist pathogen attack but researchers have focused on dissecting the induced defence response pathway. The complex signal transduction pathway underlying the establishment of resistance to a wide range of pathogen attack is currently being dissected using Arabidopsis thaliana as a model organism. Arabidopsis mutants displaying altered disease resistance response to pathogen infections can help us to get a beUer understanding of the genetiC and molecular basis of the disease resistance pathway. Extensive research has shown that accumulation of 3 signalling molecules are vitally important for establishing a resistance response, as aberrant signalling or accumulation of salicylic acid , ethylene or jasmonic acid `leads to an altered resistance response. Researchers continue to isolate and characterise defence-related mutants to piece together the intricate puzzle of defence-signalling components. A dominant Arabidopsis mutant, constitutive induced resistance 3 (cir3), had been isolated from an ethylmethane sulfonate (EMS) mutagenised transgenic line expressing luciferase under the control of the PR-1 promoter (PR-