65 
INVITED DISCUSSION 
FREE AMINO ACIDS IN NORMAL 
AND MALIGNANT PLANT TISSUES GROWN IN TISSUE CULTURE 
DAISY G. SIMONSEN ann EUGENE ROBERTS 
Department of Biochemistry, Medical Research Center, City of Hope Medical Center, 
Duarte, Calif. (U.S.A.) 
PHILIP K. WHITE 
Roscoe B. Jackson Memorial Laboratory, Bar Harbor, Me. (U.S.A.) 
Numerous aspects of the problems related to the free amino acids of plants have 
just been discussed. As described elsewhere in this Symposium (ROBERTS, SIMONSEN, 
KITTREDGE and ROBERTS), in both vertebrate and invertebrate animal species, it has 
been found that each tissue or cell type in a particular species has a characteristic 
distribution of free or easily extractable amino acids. However, quite similar patterns 
of free amino acids were found in many different types of tumors in rodents. It was 
of interest to examine in a similar manner the free amino acids in various normal and 
malignant plant tissues grown in synthetic medium? #4. 
Extracts from six to ten separate samples were chromatographed for each tissue. 
Aliquots were employed corresponding to fresh weights of each type of plant which 
ls 2 
- 
* o - af 
’ 
A 
3 : 4 

Be 
i, 

5 6 
Figs. 1-6. 1 and 2, raspberry, 150 mg fresh wt.; 3 and 4, salsify, too mg; 5 and 6, fern, 25 mg. 
All chromatograms were made by descending two-dimensional chromatography (phenol, right 
5 5 5 5 y ; 
to left; lutidine, bottom to top). 
References p. 68 
