芜菁花叶病毒提纯技术的研究

Studies on Purification Technigues for Turnip Mosaic Virus

将繁殖于大白菜上的病叶榨汁,结合聚乙二醇(PEG)沉淀及差速离心技术,拟定三种提纯程序,所得芜菁花叶病毒(TuMV)粗提纯物,可侵染芜菁、萝卜和大白菜,并在苋色藜和普通烟黄茵榆上产生局部枯斑。测定提纯物表现出典型的核蛋白紫外吸收光谱,在电镜观察下,其丝状病毒粒子形态清晰且排列疏松均匀、病毒粒子长度集中分布在730nm、宽12～13nm。用水醋酸分解、可获得本病毒的提纯的衣壳蛋白,它具有典型蛋白质紫外吸收光谱,上述三种提纯程序中,以第三种程序最佳。初步认为,若设备不足情况下省用蔗糖密度梯度离心步骤,仅用第三种提纯程序,亦可获得较好提纯效果。

Based on Chois(?)improved method, but omitting the step of sugar density gradient centrifugatios, three procedures for purification of tur- nip mosaic vrirus (TuMV) were suggested and compared. After the purif- ication, when the virus preparations were inoculated on Brassica pekinen- sis and Raphanus sativus, a systemic mosaic symptom appeared, and local lesions were also produced on indicator plants: Nicotiana tabacum cv. Huang Miao YU, and Chenopodium amaranticolor. The UV spectrum of purified TuMV showed the typical curve of nuc- leoprotein, with maximum absorption taking place at 260nm, and minlimum at 243nm, When examined with an electron microscope, flexuose rod- shaped virus particles could be observed, especially those obtained by Procedure Three were shown more clearly and in an evenly distributed manner in the field of grid. The virus particles were mainly 730nm in length and12 - 13nm in diame- ter. Pronounced contrast was achieved by mixing 2% Phosphotungstic acid with virus in clarified sap. The coat protein of TuMV under Procedure Three was obtained by using cold acetic acid to extract it, its UV spec- trum with maxirnum absorption was at 278nm, and minimum at 250nm, a marked tryptophan shoulder appeared at 288nm. A260/280 = 0.67. A comparison of these three procedures suggested that the third pro- cedure was the best.