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Etiology

Tubular Helical Structures and Fine Filaments Associated with the Leafhopper-borne Maize Yellow Stripe Virus. E. D. Ammar, Department of Plant Pathology, The Ohio State University (OSU), Ohio Agricultural Research and Development Center (OARDC), Wooster 44691, Faculty of Agriculture, Cairo University, Giza, Egypt; R. E. Gingery(2), D. T. Gordon(3), and A. E. Aboul-Ata(4). (2)Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA), Department of Plant Pathology, OSU-OARDC, Wooster 44691; (3)Department of Plant Pathology, The Ohio State University (OSU), Ohio Agricultural Research and Development Center (OARDC), Wooster 44691; (4)Virus and Mycoplasma Section, Plant Pathology Institute, Agricultural Research Center, Giza, Egypt. Phytopathology 80:303-309. Accepted for publication 5 September 1989. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1990. DOI: 10.1094/Phyto-80-303.

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 infected 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 had typical nucleoprotein ultraviolet absorbance spectra and contained fine filaments 4–8 nm in diameter. Crystallized, apparently non-virion 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.