DIASTASE ACTIVITY IN RELATION TO STAGE OF 



DEVELOPMENT AND CARBOHYDRATE 



CONTENT OF THE TUBER OF 



SOLANUM TUBEROSUM 1 



RUPERT A. McGINTY 



Formerly Rufus J. Lackland Fellow in the Henry Shaw School of Botany of 



Washington University 



The effect upon enzyme activity of various factors, such as 

 temperature, light, and different concentrations of salts, acids, 

 and alkalis, has been studied in considerable detail, and the 

 behavior of the enzymes, with respect to these factors, has 

 thrown much light upon physiological processes. One phase of 

 this question, however, has been touched upon only to a slight 

 extent, that is, the relation of enzyme activity to the various 

 stages of growth of plant organs. For this reason, it was thought 

 that a study of the activity of the enzyme diastase, in relation 

 to tuber growth in Solarium tuberosum, might prove profit- 

 able. At the same time, it was deemed of interest to follow the 

 changes in starch and sugar content at the different stages, and 

 thus determine whether any correlation exists between diastase 

 activity, growth, and carbohydrate content. 



Review of Literature 



The fundamental importance of enzymes in the processes of 

 metabolism has resulted in a voluminous literature on the sub- 

 ject, but a survey of this literature reveals only a very few 

 papers which have a direct bearing on the phase of the subject 

 considered in the present instance. These papers are briefly 

 reviewed below. A larger number have a more or less indirect 

 bearing upon the topic here discussed, and some of these will 

 also be considered. 



Probably the first observations on the presence of diastase m 

 the potato were made by Pay en and Persoz ('33). They found 



1 An investigation carried out at the Missouri Botanical Garden in the Graduate 

 Laboratory of the Henry S^haw School of Botany of Washington University, and 

 submitted as a thesis in partial fulfillment of the requirements for the degree of 

 master of arts in the Henry Shaw School of Botany of Washington University. 



Ann. Mo. Bot. Gard., Vol. 6, 1919 



(223) 



