Auxins and the Process of Aging in Root Cells 



75 



t 



o 



X 



CO 



z 

 o 



_I 



0- 



6 - 



0"- 



2 h 





 4 I- 











OLD CELLS 



b 60 



YOUNG CELLS 



r YOUNG CELLS 







0.5 







0.5 



Rf 



Fig. 7. Radiochromatograms (lAA labeled with C" in the 2-carbon atom of the 

 ring, applied to the enzyme extracts) for two types of fragments. Collections made 

 at 0, 60, and 120 min. 



RADIOCHROMATOGRAPHIC ANALYSES 



The use of lAA labeled with C^* in the 2-carbon atom of the 

 heterocyclic ring has made it possible to determine the nature of 

 lAA destruction (31) in the two types of tissue. Examination of the 

 radiochromatograms (obtained with extracts corresponding at differ- 

 ent times of incubation) indicates (Figure 7) that the speed of lAA 

 destruction is faster for the tissues of the tip. Furthermore, the deg- 

 radation products are rather different. Table 4 furnishes some 

 quantitative relations (27) on this subject. The study of the chemical 

 nature of the products resulting from the lAA (labeled with C^^) de- 

 struction by the root extracts will be presented in detail elsewhere. 

 [See P. E. Filet, Physiol. Plantarum. (in press) I960.] 



