水稻黑条矮缩病毒基因组片段6编码一种非结构蛋白

Genomic Segment 6 of Rice black-streaked dwarf virus Encodes for a Viral Non-structural Protein

水稻黑条矮缩病毒（Rice black-streaked dwarf virus，RBSDV）是引起我国水稻黑条矮缩病和玉米粗缩病的病原。引起玉米粗缩病的RBSDV湖北分离物10条基因组dsRNA全序列已被确定，其中基因组片段6（S6）全长序列为2645bp，只含有一个阅码框（82—2460nt），编码一个分子量约为89．6kDa的蛋白（P6）。为进一步研究该蛋白的生物学功能，在大肠杆菌中表达了RBSDV基因组片段6编码的P6蛋白并制备了相应的抗血清。Western blotting分析显示，P6抗血清不与纯化的RBSDV粒子蛋白发生反应，而在被RBSDV感染的玉米叶片和带毒的传播介体——灰飞虱中可检测到P6。此结果表明，RBSDV—S6编码的蛋白是一种非结构蛋白。

Rice black-streaked dwarf virus （RBSDV）can cause both maize rough dwarf and rice black streaked dwarf diseases in China. The complete sequences of all ten genomic segments（ S1 to S10 ）from an isolate of RBSDV causing rough dwarf disease on maize in Hubei Province had been determined. The S6 is 2 645 base pairs in length and contains a single long open reading frame （ORF）encoding a putative 89.6 kDa protein （P6）. In order to define the function of this protein, P6 was expressed in Escherichia coli cells and antiserum against P6 was successfully prepared. In Western blotting analysis, P6 was specifically detected in the RBSDV-infected maize leaves and the viruliferous planthoppers （ Laodel- phax striatellus）, while anti-P6 antisera did not react with any protein from purified RBSDV particles. These results suggested that RBSDV-S6 encoded a viral nonstructural protein.