Toxicity of salicylic acid and acetylsalicylic acid in Raphanussativussubmitted to water stress

摘要

Drought can cause damage to horticultural farmers and most of the plants require high amount of water for development. Substances found naturally in plants, as the hormone salicylic acid, can act as an inductor of the plant defense system against biotic and abiotic stressors. The aim of this work was to evaluate the effects of acetylsalicylic acid (ASA) and salicylic acid (SA) on Raphanus sativus under water stress. Seeds were treated with 0, 0.01, 0.1,1 and 10 mM ASA and SA solutions during 2 h. Tendays after emergence we made another application via soil: 0,0.01,0.1,1 and 10 mM ASA and SA. Analysis of antioxidant activity (DPPH) and total phenolic compounds in roots and leaves were performed to evaluate plants response to the hormone. The highestconcentration studied (10 mM of AS and ASA) was toxic to the seeds and there was no germination. In leaf and root treated with AS and ASA for all analyses the highest values were found in the control group, showing some level of toxicity. Our results demonstrate that AS and ASA do not contribute to the induced plant defense system against abiotic stressors in Raphanus sativus submitted to water stress.