SALICYLIC-ACID AS A SIGNAL MOLECULE IN PLANT-PATHOGEN INTERACTIONS

Significant insight has been gained in the past year into the roles of salicylic acid (SA) in plant-pathogen interactions. The ability to ac cumulate SA has been shown to be essential for systemic acquired resis tance in tobacco plants. Further experiments have shown that SA is app arently not a systemic, vascular-mobile signal, but rather is required for signal transduction at the local level. Its mode of action may in clude inhibition of catalase activity, leading to increased levels of hydrogen peroxide.