Gibberelliyi-Auxin Interaction and Metabolic Basis 625 



since, when you have two pieces of plants growing at 100 per cent 

 difference in elongation, you have a different morphological pattern. 

 You have, ot course, referred activity to amount of protein, which is 

 the most natural way, but it does not necessarily follow that this is 

 the right expression of the real activity of the enzyme when you have 

 such a fundamental difference in the organization of the tissues, as 

 you must have. 



Dr. Galston: Your point is certainly well taken. Remember, how- 

 ever, that although we produced only a 40 per cent change in over-all 

 peroxidase activity, we have produced very much greater changes in 

 one or two of the electrophoretically separable peroxidase peaks. The 

 changes can be of the order of several hundred per cent when cal- 

 culated for the individual peroxidase components. As for the mechan- 

 ism by means of which a peroxidase could inhibit growth, we do not 

 know. It may destroy auxin, it may make lignin, or it may do other 

 things. All we can say is that we have here a specific reversal by gib- 

 berellin of a biochemical abnormality in a single gene dwarf mutant. 

 Whether this has significance for the control of growth is for the fu- 

 ture to tell. 



