VIEW ARTICLE

An Inhibitor of Tobacco Mosaic Virus Produced by Physarum polycephalum. Dennis E. Mayhew, Graduate Teaching Assistant, Department of Botany and Plant Pathology, Iowa State University, Ames 50010; R. E. Ford, Professor, Department of Botany and Plant Pathology, Iowa State University, Ames 50010. Phytopathology 61:636-640. Accepted for publication 4 January 1971. DOI: 10.1094/Phyto-61-636.

An inhibitory substance produced by Physarum polycephalum prevents tobacco mosaic virus (TMV) infection when assayed on beans and tobacco. The 35,000-55,000 mol wt inhibitor has properties of a carbohydrate, and is stable in high temperature and high pH. Foliar application before and after inoculation of TMV prevents TMV infection on beans. Dilution and high temperature treatment of the virus-inhibitor complex reverses inhibition. Electron micrographs suggest that the inhibitor coats TMV, thus preventing normal coat “stripping”. The inhibitor reduced tobacco ringspot virus infection in Vigna sinensis but not that of southern bean mosaic virus in Phaseolus vulgaris.