Water Status of Tomato Plugs Sprayed with (+) -S-Abscisic Acid and Stored in the Dark at Room Temperature

The effects of (+) -S-abscisic acid (ABA) on the water status of stored tomato (Lycopersicon esculentum Mill.) plugs were investigated. Plugs were sprayed at the 4-leaf stage with ABA at 0, 20, 100, or 500 mg L-1 and stored in the dark at room temperature for 10 d. The water status of the plugs and soil was measured with isopiestic psychrometers. No growth occurred during storage. Untreated plugs wilted : the water potential and turgor of their leaves decreased significantly. However, the water potential and turgor of leaves treated with ABA were maintained. These results suggest that ABA treatment reduces wilting by controlling transpiration and osmotic adjustment.