Acetyl salicylic acid (Aspirin) and salicylic acid induce multiple stress tolerance in bean and tomato plants

The hypothesis that physiologically active concentrations of salicylic acid (SA) and its derivatives can confer stress tolerance in plants was evaluated using bean (Phaseolus vulgaris L.) and tomato (Lycopersicon esculentum L.). Plants grown from seeds imbibed in aqueous solutions (0.1-0.5 mM) of salicylic acid or acetyl salicylic acid (ASA) displayed enhanced tolerance to heat, chilling and drought stresses. Seedlings acquired similar stress tolerance when SA or ASA treatments were applied as soil drenches. The fact that seed imbibition with SA or ASA confers stress tolerance in plants is more consistent with a signaling role of these molecules, leading to the expression of tolerance rather than a direct effect. Induction of multiple stress tolerance in plants by exogenous application of SA and its derivatives may have a significant practical application in agriculture, horticulture and forestry.