Purification and Some Properties of Two Strains of Soybean Dwarf Virus

Publisher Website
Google Scholar
Abstract
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. A260/280 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).