Tubular Helical Structures and Fine Filaments Associated with the Leafhopper-borne Maize Yellow Stripe Virus

Publisher Website
Google Scholar
Abstract
A new disease agent, designated maize yellow stripe virus (MYSV) and transmitted in a persistent manner by the leafhopper Cicadulina chinai, is associated with three types of symptoms on infected plants: fine stripe, coarse stripe, and chlorotic stunt. Light and electron microscopy of naturally or experimentally maize or sorghum leaves showing any of these three symptoms revealed the presence of large, amorphous, intracytoplasmic inclusions in phloem elements, vascular parenchyma, bundle sheath, and mesophyll cells. These inclusions contained masses of long, flexuous, tubular structures, approximately 34 nm in diameter, apparently composed of helically wound filaments 5-7 nm thick. These structures commonly were associated with or sandwiched between aggregated mitochondria, some of which were degenerated. Some of the cells containing tubular structures also contained masses of loosely or densely packed fine fibrils. Purified preparations obtained from naturally infected leaves and typical nucleoprotein ultraviolet absorbance spectra and contained fine filaments 4-8 nm in diameter. Crystallized apparently nonvirion protein also was purified from these leaves and was serologically unrelated to the noncapsid protein of maize stripe virus (MStV). Crude extracts from infected leaves did not react with antisera to the capsid protein of MStV or to several other maize viruses and spiroplasma in enzyme-linked immunosorbent assay. Similarities and differences between MYSV and tenuiviruses (rice stripe virus group) are discussed.