Characterization of Proteins and Nucleic Acid of Rice Stripe Virus / 中国病毒学

ABSTRACT

An isolate of rice stripe virus (designated as RSV-YL) was purified. The particles showed to be pleomorphisms under electron microscope, mainly branched filaments of about 80-250 nm in length and about 8 nm in width. There are also some open circular filaments of 3 nm and 8 nm in width, and some filaments of 13 nm in width and 130-190 nm in length. The basic morphism of RSV particles should be filaments of 3 nm in width and various length. By SDS-PAGE analysis, the molecular weight of disease-specific protein (SP) encoded by vRNA4 was 19.9 kDa and that of coat protein (CP) encoded by vcRNA3 was 33.6 kDa. When nucleic acid extracted from the purified RSV was electrophoresed under nondenaturing condition, the size of four dsRNAs (designated as dsRNA1-4 in order of decreasing size) was 4.9×106,2.7×106,2.0×106 and 1.7×106 Da, respectively, and that of four ssRNAs (designated as ssRNA1-4 in order of decreasing size) was 3.0×106,1.2×106,0.9×106 and 0.8×106 Da, respectively. A fifth segment with a size of 0.58×106 Da identified as ssRNA5 associated with the purified virus sometimes. The antiserum against the coat protein further purified by preparative electrophoresis was raised and used to investigate the serological relationships between RSV-CP and RSV-SP, CP and SP of rice grassy stunt virus (RGSV) which is also a member of Tenuivirus. The results showed that RSV-CP had no serological reaction with SP of RSV and PGSV, but could weakly react with antiserum of RGSV-CP, which confirmed that there is distantly evolutionary relationship between RGSV and RSV.