Lee Lawrence, Palukaitis Peter, Gray Stewart M
United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, Cornell University, Ithaca, NY 14850, USA.
Mol Plant Microbe Interact. 2002 Oct;15(10):1086-94. doi: 10.1094/MPMI.2002.15.10.1086.
The requirement for the 17-kDa protein (P17) of Potato leafroll virus (PLRV) in virus movement was investigated in four plant species: potato (Solanum tuberosum), Physalis floridana, Nicotiana benthamiana, and N. clevelandii. Two PLRV P17 mutants were characterized, one that does not translate the P17 and another that expresses a P17 missing the first four amino acids. The P17 mutants were able to replicate and accumulate in agroinoculated leaves of potato and P. floridana, but they were unable to move into vascular tissues and initiate a systemic infection in these plants. In contrast, the P17 mutants were able to spread systemically from inoculated leaves in both Nicotiana spp., although the efficiency of infection was reduced relative to wild-type PLRV. Examination of virus distribution in N. benthamiana plants using tissue immunoblotting techniques revealed that the wild-type PLRV and P17 mutants followed a similar movement pathway out of the inoculated leaves. Virus first moved upward to the apical tissues and then downward. The P17 mutants, however, infected fewer phloem-associated cells, were slower than wild-type PLRV in moving out of the inoculated tissue and into apical tissues, and were unable to infect any mature leaves present on the plant at the time of inoculation.
在四种植物中研究了马铃薯卷叶病毒（PLRV）的17 kDa蛋白（P17）在病毒移动中的作用，这四种植物分别是：马铃薯（Solanum tuberosum）、弗罗里达酸浆（Physalis floridana）、本氏烟草（Nicotiana benthamiana）和克利夫兰烟草（N. clevelandii）。对两个PLRV P17突变体进行了表征，一个不翻译P17，另一个表达缺失前四个氨基酸的P17。P17突变体能够在马铃薯和弗罗里达酸浆经农杆菌接种的叶片中复制和积累，但它们无法进入维管组织并在这些植物中引发系统感染。相比之下，P17突变体能够在两种烟草属植物中从接种叶片系统扩散，尽管相对于野生型PLRV，感染效率有所降低。使用组织免疫印迹技术检查本氏烟草植株中的病毒分布发现，野生型PLRV和P17突变体从接种叶片出来后遵循相似的移动途径。病毒首先向上移动到顶端组织，然后向下移动。然而，P17突变体感染的韧皮部相关细胞较少，从接种组织移动到顶端组织的速度比野生型PLRV慢，并且无法感染接种时植株上已有的任何成熟叶片。
