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 evaluat ed using bean (Phaseolus vulgaris L.) and tomato (Lycopersicon esculentum L .). Plants grown from seeds imbibed in aqueous solutions (0.1-0.5 mM) of sa licylic acid or acetyl salicylic acid (ASA) displayed enhanced tolerance to heat, chilling and drought stresses. Seedlings acquired similar stress tol erance when SA or ASA treatments were applied as soil drenches. The fact th at seed imbibition with SA or ASA confers stress tolerance in plants is mor e consistent with a signaling role of these molecules, leading to the expre ssion of tolerance rather than a direct effect. Induction of multiple stres s tolerance in plants by exogenous application of SA and its derivatives ma y have a significant practical application in agriculture, horticulture and forestry.