The Effect of 2,4-Dichlorophenoxyacetic Acid on Pathways of Glucose Catabolism in Higher Plants.

Abstract

The yields of C14O2 from glucose-1-C14 and glu-cose-6-C14 in short time expts. were used to evaluate the participation of the glycolytic and the pentose phosphate pathways of glucose catabolism in root tips of 2,4-dichlorophenoxyacetic acid (2, 4-D) treated and untreated pea (Pisum sativum), corn (Zea mays) and oat (Avena sativa) seedlings. In all seedlings except pea seedlings treated with the cotyledons attached, 2,4-D (10-3M) caused an increase in the amount of radioactive glucose catabolized, and this extra glucose was catabo-lized via the pentose phosphate pathway. With pea seedlings treated with the cotyledons attached, 2,4-D caused an increase in the amount of glucose catabolized via the pentose phosphate pathway, but it also caused a decrease in the amount catabolized via the glycolytic pathway. The fraction of glucose catabolized via the glycolytic pathway in root tips of untreated corn seedlings varied with the moisture condition obtaining during germination. The effect of indoleacetic acid (IAA) on glucose catabolism also was studied and it was concluded that IAA does not influence glucose catabolism in the same manner as does 2,4-D.