VIEW ARTICLE

Alteration of Tobacco Streak Virus Component Ratios as Influenced by Host and Extraction Procedure. R. M. Lister, Associate Professor, Department of Botany and Plant Pathology, Purdue University, Lafayette, Indiana 47907; J. B. Bancroft, Professor, Department of Botany and Plant Pathology, Purdue University, Lafayette, Indiana 47907. Phytopathology 60:689-694. Accepted for publication 11 November 1969. DOI: 10.1094/Phyto-60-689.

For two strains of tobacco streak virus, the proportions of the nucleoprotein components and the total yield of nucleoprotein varied with host and the precise extraction procedures. For the bean red node strain, Chenopodium quinoa tissue extracted directly at pH 5 yielded more total nucleoprotein and a greater proportion of a slowly-sedimenting “top component” than did tissue extracted at pH 7 and subsequently adjusted to pH 5 for clarification. With Phaseolus vulgaris as the source, precisely the reverse situation applied. The ratio of nucleoprotein components could be varied by adding healthy leaves to infected leaves of the heterologous host before extraction, but not by mixing virus with various leaf-extracts or by blending purified virus with leaves. The virus was electrophoretically homogeneous. Nucleoprotein component proportions were unaffected by the use of detergent, prolonged extraction, or re-extracting fiber. Oxidative reactions and possible direct effects of pH on virus during extraction did not appear to be a factor. All the evidence suggests that unexplained pH-mediated and host-regulated effects governed extraction per se.