VIEW ARTICLE

Physiology and Biochemistry

Purification and Some Properties of Two Strains of Soybean Dwarf Virus. Adrianna D. Hewings, Research plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, Plant Disease Research Laboratory, Frederick, MD 21701; Vernon D. Damsteegt(2), and Sue A. Tolin(3). (2)Research plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, Plant Disease Research Laboratory, Frederick, MD 21701; (3)Professor, Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg 24061. Phytopathology 76:759-763. Accepted for publication 31 January 1986. 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, 1986. DOI: 10.1094/Phyto-76-759.

A dwarfing (SDV-D) and a yellowing (SDV-Y) strain of soybean dwarf virus from Japan were purified from Wayne soybeans 15-20 days after inoculation. Yields were highest when the virus was extracted by pulverizing stem and leaf tissue in liquid nitrogen, mixing the powder with 0.5 M sodium phosphate, pH 6, (1:2, w/v) and a 2% industrial-grade pectin glycosidase, and stirring the slurry at room temperature for 6 hr. Extracts were clarified with 10% each (v/v) of chloroform and butanol. Concentration and final purification were by two cycles of differential centrifugation and sucrose density gradient centrifugation. Each isolate sedimented as a single band containing 26-nm-diameter icosahedral particles. Yields were 0.1-0.2 mg/kg for the dwarfing strain and 0.15-0.3 mg/kg for the yellowing strain. Each strain had an absorbance maximum at 259 nm and a minimum at 242 nm. A_{260 280 nm} ratios, corrected for light-scattering, were 1.85 (SDV-D) and 1.83 (SDV-Y). Sedimentation coefficients corrected to 20 C in water were 108 (SDV-D) and 114 (SDV-Y). SDV-D banded isopycnically in CsCl at a density of 1.39 and SDV-Y at 1.41 g/ml. The relative molecular masses of the major proteins were 22,200 (SDV-D) and 22,700 (SDV-Y).