RT Journal Article SR Electronic T1 A Central Role of Salicylic Acid in Plant Disease Resistance JF Science JO Science FD American Association for the Advancement of Science SP 1247 OP 1250 DO 10.1126/science.266.5188.1247 VO 266 IS 5188 A1 Delaney, Terrence P. A1 Uknes, Scott A1 Vernooij, Bernard A1 Friedrich, Leslie A1 Weymann, Kris A1 Negrotto, David A1 Gaffney, Thomas A1 Gut-Rella, Manuela A1 Kessmann, Helmut A1 Ward, Eric A1 Ryals, John YR 1994 UL http://science.sciencemag.org/content/266/5188/1247.abstract AB Transgenic tobacco and Arabidopsis thaliana expressing the bacterial enzyme salicylate hydroxylase cannot accumulate salicylic acid (SA). This defect not only makes the plants unable to induce systemic acquired resistance, but also leads to increased susceptibility to viral, fungal, and bacterial pathogens. The enhanced susceptibility extends even to host-pathogen combinations that would normally result in genetic resistance. Therefore, SA accumulation is essential for expression of multiple modes of plant disease resistance.