68 D. G. SIMONSEN, E. ROBERTS, P. R. WHITE 
tumors which have been studied, the glutamine levels have been extremely low, 
usually below the level of detection by chromatographic methods, while relatively 
large amounts were found in normal tissues®. This amino acid was easily detectable 
in the cultured plant tumors and no distinction could be made between the normal 
and malignant plant tissues on the basis of glutamine content. 
In Figs. 17-24 are shown the chromatograms of extracts of samples of two sepa- 
rately isolated hybrid strains of tobacco (Nicotinia; N. glauca x N. Langsdorfit). 
In Figs. 17 and 18 are shown extracts of a strain (NA) which was isolated by Dr. 
WHITE in 1949 and which behaves more like normal tissue than the strain (N) of 
the same hybrid which was isolated in 1937 (Figs. 1g and 20) and which is tumorous. 
The NA strain showed a much higher concentration of ninhydrin-reactive constit- 
uents per unit fresh weight of tissue than strain N at 2 months of culture and also 
in 4-5 month cultures (Figs. 21 and 22, NA strain; Figs. 23 and 24, N strain). 
Although the patterns of the two strains obviously differ from each other, there 
appears to be more resemblance between them than noted between any of the pre- 
viously discussed samples shown for either normal or tumor samples. Thus, there 
is a distribution of constituents in the samples of strain N shown in Figs. 23 and 
24 which is similar to that found in some samples of strain NA (Figs. 17, 18, and 
21). In all instances there was less glutamine in strain N. 
The above results show clearly that each of the excised plant tissues grown on 
the same medium attains its own characteristic pattern of ninhydrin-reactive 
constituents and that no aspect of the pattern can be related to the “normality” 
or “malignancy” of these tissues. These results cannot be held to be strictly anal- 
ogous to those obtained with animal tissues, since a wide range of plant species 
was examined, while the animal tumors were only from rats and mice. 
ACKNOWLEDGEMENT 
This work was supported in part by grants C-2568 (to E.R.) and C-2061 (to P.R.W.) 
from the National Cancer Institute, National Institutes of Health. 
REFERENCES 
1 J. REINERT AND P. R. WuiteE, Physiol. Plantarum, 9 (1956) 177. 
2 P. R. Wuite, Plant Physiol., 12 (1937) 793. 
3 P. R. Wuite, Plant Phystiol., 14 (1939) 527. 
4P. R. Wuite, Ann. Rev. Plant Physiol., 2 (1950) 231. 
5 E. ROBERTS AND D.G. SIMONSEN, in J. T. EpsaLt, Amino Acids, Proteins and Cancer Bio- 
chemistry, Academic Press Inc., New York, 1960, p. 121. 
