Sugarcane mosaic virus infection of seedling roots of Zea mays and Sorghum halepense

Abstract

Sugarcane mosaic virus (SCMV) multiplication was studied in roots of Zea mays L. (Golden Bantam sweet corn) and Sorghum halepense L. (Johnson grass). Mechanical inoculation of corn roots with SCMV did not result in systemic infection, and SCMV could be recovered from only nine of 1950 inoculated roots. Some virus was detected in roots of young leaf-inoculated seedlings. Attempts to purify SCMV from these roots did not yield detectable virus, while 2 mg virus per 100 g host tissue was obtained from leaf tissue. Ultrastructural changes in systemically infected root tip cells of corn and Johnson grass included pinwheel inclusions in epidermal cells of corn, characteristic of the potato virus Y group. Bundle inclusions were found in bundle sheath parenchyma cells of corn root tips. Bundle inclusions, but not pinwheels, were found throughout the root tips of infected Johnson grass roots. Significant changes in levels of nitrogen and carbohydrate were found in SCMV-infected shoots and roots.