VIEW ARTICLE

Etiology

Purification and Characterization of a Virus Associated with the Grapevine Leafroll Disease. Edna Tanne, The Agricultural Research Organization, Volcani Center, Bet Dagan, Israel; I. Sela(2), M. Klein(3), and I. Harpaz(4). (2)(3)(4)Virus Laboratory, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel. Phytopathology 67:442-447. Accepted for publication 26 August 1976. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-442.

Grape leafroll virus (GLRV) which is associated with the leafroll disease in grapevine, and also is transmissible to herbaceous plants, was purified from Nicotiana glutinosa and Datura metel and characterized. Purification involved a combination of solvent extraction, polyethylene glycol precipitation, differential centrifugation, and equilibrium density-gradient centrifugation in CsCl. Flexuous, rod-shaped, infectious virus particles were found in the purified preparation. They were heterogeneous in size due to fragility and aggregation. The sedimentation coefficient of the n normal-size particle (13 × 790 nm) was about 150S. The virus formed a single band at 1.32 g/cm³ upon CsCl equilibrium centrifugation. Viral RNA extracted from purified GLRV formed a single, though somewhat diffuse, band upon agarose-acrylamide slab-gel electrophoresis. The molecular weight of GLRV-RNA was estimated as 2.9 - 3.5 × 10⁶. Infective GLRV-RNA could be eluted out of polyacrylamide gels. A single protein band, 31,000 daltons in molecular weight, was detected upon polyacrylamide gel electrophoresis of purified GLRV in the presence of sodium dodecyl sulfate or urea. No virus particles were found in ultrathin sections of GLRV-infected tissues of either grapevine, N. glutinosa, or D. metel. In dip preparations, however, virus particles were readily observed in the sap of the above herbaceous plants, but not in grapevines. A variety of inclusion bodies and abnormal structures were observed in ultrathin sections of N. glutinosa and D. metel. These included pinwheeles, bundles of filaments, arrays of crystalline matter, and giant mitochondria. Grape leafroll virus is classified in the potyvirus group.