SURGICAL INVESTIGATION OF THE ROLE OF IAA AND GA IN THE ELONGATION OF‘METEOR’PEA INTERNODES

Abstract

The elongation of the second internode of Meteor pea seedlings and the relationship of this elongation to cell division and cell elongation in the epidermis and cortex has been determined after treatment with either IAA or GA or both together, and in combination with decapitation, and removal of the first or second leaves either separately or together. The cells from the side of the internode subtending the second leaf are consistently longer than on the other side, and this effect is intensified by application of GA and abolished by application of IAA. Decapitation and defoliation together abolish the usual stimulation of cell elongation by GA. It is concluded that the results are in harmony with the hypothesis that the cell elongating effect of GA is the result of an increased production of auxin in the apical regions and young leaves. Copyright © 1967, Wiley Blackwell. All rights reserved