Briddon R W, Pinner M S, Stanley J, Markham P G
Department of Virus Research, John Innes Institute, AFRC Institute of Plant Science Research, Norwich, United Kingdom.
Virology. 1990 Jul;177(1):85-94. doi: 10.1016/0042-6822(90)90462-z.
Chimeric clones have been constructed in which the coat protein encoded by DNA A of the bipartite genome of the geminivirus African cassava mosaic virus (ACMV) has been replaced by that of beet curly top virus (BCTV). Constructs containing the coding region inserted in either orientation were infectious when co-inoculated with ACMV DNA B onto Nicotiana benthamiana, producing symptoms typical of ACMV infection. The onset of symptom production was delayed relative to plants inoculated with parental ACMV clones and remission of symptoms was observed. When inserted in the correct orientation for expression from the ACMV coat protein promoter, the BCTV gene was expressed in plants and the coat protein synthesized encapsidated ssDNA of both ACMV genomic components. The BCTV leafhopper vector, Circulifer tenellus (Baker), transmitted both BCTV and the chimeric virus but not ACMV when injected with virus preparations and transferred to N. benthamiana seedlings. The results show that the specificity of leafhopper transmission from insect to plant resides with the coat protein.
已构建嵌合克隆，其中双生病毒非洲木薯花叶病毒（ACMV）二分基因组的DNA A编码的外壳蛋白已被甜菜曲顶病毒（BCTV）的外壳蛋白取代。当与ACMV DNA B共同接种到本氏烟草上时，含有以任一方向插入的编码区的构建体具有感染性，产生典型的ACMV感染症状。与接种亲本ACMV克隆的植株相比，症状产生的起始延迟，并且观察到症状缓解。当以正确的方向插入以从ACMV外壳蛋白启动子表达时，BCTV基因在植物中表达，并且合成的外壳蛋白包裹了ACMV两个基因组组分的单链DNA。当用病毒制剂注射并转移到本氏烟草幼苗上时，BCTV叶蝉载体Circulifer tenellus（Baker）传播BCTV和嵌合病毒，但不传播ACMV。结果表明，叶蝉从昆虫到植物的传播特异性在于外壳蛋白。
