88 Fundamentals of Auxin Action 



ceivably occur in step 3, wherein the pigment or flavo-protein is 



regenerated to its original reduced form. 



If auxin destruction takes place in aerobic conditions, oxygen is 

 consumed in amounts comparable to the amount of auxin destroyed 

 (Galston, 1949). The non-enzymatic destruction can occur in the ab- 

 sence of oxygen though more slowly. In this case the pigment is 



LJ 



< 

 < 



50 



100 



150 MIN. 



TIME IN LIGHT 



Fig. 44. The destruction of auxin by the pea enzyme in dark, in light, and after 

 dialysis of the enzyme (Galston and Baker, 1951). 



bleached, probably because of its being reduced by hydrogen from the 

 auxin (Galston, 1949) as in step 3 (figure 43) or possibly by hydrogen 

 from water (Brauner and Brauner, 1954). 



In an investigation of the nature of the light effect in the enzy- 

 matic reaction, Galston and Baker (1951) have found that there is a 

 natural inhibitor of the reaction in pea tissues, and that light serves 

 to overcome the effect of this inhibitor. In this way light permits the 

 destruction of auxin to proceed. Some data on this point can be seen 



