小麦梭条花叶病毒及其不同致病力分离物的外壳蛋白特性研究

A Study on some Properties of Coat Proteins of Wheat Spindle Streak Mosaic Virus Isolates with Different Pathogenicity

SDS—聚丙烯酰胺不连续凝胶电泳试验结果表明,小麦梭条花叶病毒外壳蛋白是由分子量为36kd的单一亚基组成,但不同致病力分离物的稳定性有明显差异。稳定性较差的分离物外壳蛋白极易降解成2种分子量(30—33kd和26—27kd)甚至更小的产物。降解程度(速度)明显受到制备病毒制剂的提纯和电泳前处理方法的影响。这一结果初步解释了国内外研究结果不相一致的原因;提出必须选用稳定的提纯方法,并在此基础上添加蛋白酶抑制剂,才能更有效地制备病毒电泳制剂和测定外壳蛋白组分。本研究结果还将对明确WSSMV种类,探明WSSMV与MYMV的关系,鉴别WSSMV分离物和汁液接种试验具有重要意义。

The properties of coat protein of wheat spindle streak mosaic virus (WSSMV) were studied by SDS-polyacrylamide gel eleotrophoresis. The results show that WSSMV coat protein is composed of a single subunit with a molecular weigh of 35 kd. The coat protein of WSSMV is unstable and easy to degrade during virus pruification to give products with smaller molecular weights of 30-33 kd arid 26-27 kd. This unstability is different among different pathogenicity isolates collected from various sites in China. The degradation may be different due to different methods of purification and can be minimized by suitable methods. These findings can help to explain the different results reported on the coat protein of WSSMV and the relation between WSSMV and WYMV. Their implication in identification of isolates and mechariical transmissibility is discussed.