Early Events Associated with Lateral Bud Growth of Pisum sativum L.

Abstract

Using a method which measures small changes in length of lateral buds of Pisum sativum L. 'Alaska,' acceleration of lateral bud growth is observed after a lag period of 6-8 h following apex removal or after addition of 1 μM benzyladenine to rootless plants. Cell division either accompanies or occurs after, but does not precede, growth stimulations caused by decapitation or benzyladenine application; mitoses are found throughout the tissues of the bud. An inhibitor of gibberellin synthesis, CCC, retards bud outgrowth, but the effect is not reversed by addition of 1 mM gibberellic acid, suggesting some nonspecific effect of the inhibitor. Bud outgrowth occurs more rapidly when a 0.5-cm internode remains after decapitation than when a 7-cm internode remains. The difference in length of the buds is due to a difference in lag period (not rate of growth) and may be related to transport of auxin through the internode.