Phytopathology. 1999 Dec;89(12):1176-81. doi: 10.1094/PHYTO.1999.89.12.1176.
ABSTRACT The aphid transmission properties of a pepper isolate of potato virus Y belonging to the pathotype 1-2 (PVY 1-2) have been characterized. PVY 1-2 was not transmitted in plant-to-plant experiments, although purified virus particles were efficiently transmitted when supplemented with heterologous helper component (HC) of the transmissible isolate PVY 0 AT through membrane acquisition assays, indicating that its coat protein was functional in transmission. Additionally, virions of PVY 1-2 were able to bind to different HCs in in vitro binding assays. Analysis of the sequence of the PVY 1-2 HC gene and comparison with that of PVY 0 AT revealed 19 nucleotide differences, but only 2 resulted in amino acid changes, one of which induced a change of charge. Neither of these two amino acid changes occurred within the cysteine-rich domain, nor did they coincide with conserved motifs of the HC protein known to be involved in aphid transmission and which are present in all known potyvi-ruses. However, both changes are located in positions highly conserved among PVY strains. The possible role of both mutations on the activity of the PVY 1-2 HC in aphid transmission is discussed.
摘要 本研究对属于 1-2 型（PVY 1-2）的辣椒分离物中马铃薯 Y 病毒（PVY）的蚜虫传播特性进行了分析。在植株间实验中，PVY 1-2 未被传播，尽管当通过膜获得测定用传染性分离物 PVY 0 AT 的异源辅助成分（HC）进行补充时，纯化的病毒颗粒能够有效地进行传播，表明其外壳蛋白在传播中具有功能。此外，在体外结合测定中，PVY 1-2 的病毒粒子能够与不同的 HC 结合。对 PVY 1-2 HC 基因的序列分析并与 PVY 0 AT 的序列进行比较，发现了 19 个核苷酸差异，但只有 2 个导致氨基酸变化，其中一个引起电荷变化。这两个氨基酸变化均未发生在富含半胱氨酸的结构域内，也未发生在已知参与蚜虫传播且存在于所有已知的 P 病毒中的 HC 蛋白的保守基序内。然而，这两个变化均位于 PVY 株之间高度保守的位置。讨论了这两个突变对 PVY 1-2 HC 在蚜虫传播中的活性的可能作用。
