Effect of ‘Tobacco Leaf-Curl’ and Tobacco Mosaic Virus on the Amino-acid and Amide Content of Nicotiana sp.

Abstract

THE results of Martin, Balls and McKinney¹, Meneghini and Delwiche², Commoner et al. ³ and others have shown that virus synthesis is associated with a remarkable increase in the soluble protein content of Nicotiana leaves infected with tobacco mosaic virus. Takahashi and Mamoru⁴, and Commoner et al. ⁵, have resolved and isolated a new protein from virus-free extracts of mosaic tobacco leaves, which was not detected by Wildman, Cheo and Bonner⁶, by electrophoresis. A study of free and hydrolysed protein of both healthy and virus-infected leaves, by a modified technique of horizontal paper chromatography, has revealed the absence of a ninhydrin-reacting substance (present in healthy leaves) from the water extract of leaves infected with tobacco mosaic virus and leaves infected with tobacco curl virus. Further, the water-soluble extracts of diseased leaves revealed the presence of two new bands corresponding to asparagine and histidine–lysine.