Salt and Abscisic Acid Effects on 2,4,5-T Translocation

Abstract

The effects of chloride salts of potassium, sodium, ammonium, and lithium and abscisic acid (ABA) on the translocation of 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] in bean (Phaseolus vulgarisL. Var. Stringless Green-pod) seedlings were determined.14C-labeled 2,4,5-T was injected in the stem tissue at the cotyledonary node in a 1-μl volume along with ABA. The salts were added to the nutrient solution at 20 mM concentrations at the time of 2,4,5-T treatment. Sodium chloride inhibited 2,4,5-T accumulation in the upper portion of the plant; and except for LiCl, the salts tended to increase accumulation in the nutrient solution. LiCl increased 2,4,5-T accumulation in the young shoots and primary leaves and decreased accumulation in the roots and nutrient solution. The effects of ABA on 2,4,5-T translocation were similar to the effects of NaCl but were more pronounced. ABA caused large decreases in 2,4,5-T translocation to the young shoots and primary leaves and increased accumulation in the nutrient solution.