VIEW ARTICLE

Purification and Properties of Pea Seed-Borne Mosaic Virus. J. E. Knesek, Research Virologist, M. D. Anderson Hospital and Tumor Institute, University of Texas, Houston 77025; G. I. Mink(2), and R. O. Hampton(3). (2)Plant Pathologist, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350; (3)Research Plant Pathologist, Plant Science Research Division Western Region ARS, USDA, Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331. Phytopathology 64:1076-1081. Accepted for publication 15 February 1974. DOI: 10.1094/Phyto-64-1076.

Pea seed-borne mosaic virus (PSbMV) was purified from roots and leaves of systemically infected Pisum sativum '447'. Of several procedures investigated, best results were obtained by grinding root tissue in 0.01 M sodium diethyldithiocarbamate (NaDIECA) + 0.01 M cysteine or leaf tissue in NaDIECA + cysteine containing 0.01 M ethylenediaminetetraacetic acid (EDTA) and clarifying with one-half volume of chloroform. Clarified suspensions were concd by one cycle of differential ultracentrifugation, and further purified by centrifugation on columns containing 30% sucrose, 4% polyethylene glycol MW 6000, and 0.12 M NaCl. Precipitated virus was suspended in 2% sucrose containing 0.1% Igepon T73 at pH 7.0. This procedure yielded a single, highly infectious, visible zone 24-26 mm below the meniscus of rate sucrose density-gradient tubes: healthy tissue handled similarly produced no visible zones. The virus had a sedimentation coefficient of 148 ± 1 S and contained 5.3% ribonucleic acid with a base ratio of adenine 44.0%, guanine 22.8%, cytidylic acid 17.6%, and uridylic acid 15.6%. The protein coat contained aspartic acid and glutamic acids in greatest amounts. Elongated flexuous rods with a modal length of 770 nm were found in preparations fixed with 3.5% glutaraldehyde. All properties of PSbMV were similar to those reported for other viruses in the potato virus Y group.