Drought Tolerance Induced by Foliar Application of Abscisic Acid and Sulfonamide Compounds in Tomato

Abstract

The effects of exogenous abscisic acid and two sulfonamide compounds: Sulfacetamide and Sulfasalazine were studied on tolerance of tomato (Lycopersicon esculentum Mill. cv. Super chief) under drought stress and compared with abscisic acid effects. Eight-week old plants were treated with ABA (10 and 25 mg/L), Sulfacetamide (25, 50 and 100 mg/L) and Sulfasalazine (25, 50 and 100 mg/L). Solutions were sprayed daily and sampling was done at 0 h, 48 h, 96 h, 144 h and 48 h after re-watering (recovery phase or 192 h). Treated plants showed relatively greater drought tolerance. This indicates that, Sulfacetamide and Sulfasalazine may improve resistance in tomato, like ABA, increasing levels of proline, glycine betaine and malondialdehyde and the activity of ascorbate peroxidase. Daily application of Sulfasalazine and Sulfacetamide during drought stress period was effective in increasing tomato plants tolerance to drought as was ABA.

Keywords

• Abscisic acid
• Glycine betaine
• Proline
• Sulfacetamide
• Sulfasalazine