College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China.
Institute of Plant Virology, Ningbo University, Ningbo, 315200, China.
Virus Res. 2019 Jul 2;267:9-15. doi: 10.1016/j.virusres.2019.04.007. Epub 2019 Apr 27.
Pepper mild mottle virus (PMMoV) causes mosaic symptoms and malformation on both leaf and fruit of pepper, reduces considerable economical yields and poses threats to human health. In this study, infectious clone of PMMoV Huludao (HLD) isolate (pCB-PMMoV-HLD) was constructed and its infectious ablility in Nicotiana benthamiana was confirmed by virions observation and Northern blot analysis. The mutant PMMoV (HLD-fsCP) that cannot express coat protein (CP) showed reduced viral accumulation but can systemically infect N. benthamiana. We constructed several chimeric mutant viruses (ZA-HB-HC, HA-ZB-HC, HA-HB-ZC and HA-ZB-ZC) by sequences substitution between PMMoV-HLD and PMMoV Zhejiang isolates (PMMoV-ZJ) and analyzed their infectious abilities in N. benthamiana and Capsicum annuum. The results showed that the chimera virus expressed by pCB-ZA-HB-HC, pCB-HA-HB-ZC and pCB-HA-ZB-ZC, but not by pCB-HA-ZB-HC, exhibited reduced infectious ability compared with wild-type PMMoV-ZJ and PMMoV-HLD, which indicated that RNA sequences required for efficient infection of PMMoV differ between the two virus isolates. The differential requirement of viral RNA sequences for efficient PMMoV infection provided theoretical value to further understand the infection and pathogenesis of PMMoV.
胡椒轻斑驳病毒（PMMoV）可导致胡椒叶片和果实出现花叶和畸形症状，造成严重的经济损失，并对人类健康构成威胁。本研究构建了胡椒轻斑驳病毒葫芦岛（HLD）分离物（pCB-PMMoV-HLD）的感染性克隆，并通过病毒粒子观察和 Northern blot 分析证实了其在本氏烟中的感染能力。不能表达外壳蛋白（CP）的突变型 PMMoV（HLD-fsCP）病毒积累减少，但仍可系统感染本氏烟。我们通过胡椒轻斑驳病毒 HLD 与浙江分离物（PMMoV-ZJ）之间的序列替换构建了几种嵌合突变病毒（ZA-HB-HC、HA-ZB-HC、HA-HB-ZC 和 HA-ZB-ZC），并分析了它们在本氏烟和辣椒中的感染能力。结果表明，pCB-ZA-HB-HC、pCB-HA-HB-ZC 和 pCB-HA-ZB-ZC 表达的嵌合病毒，而非 pCB-HA-ZB-HC 表达的嵌合病毒，与野生型 PMMoV-ZJ 和 PMMoV-HLD 相比，其感染能力降低，这表明两种病毒分离物中用于 PMMoV 有效感染的 RNA 序列不同。PMMoV 有效感染所需的病毒 RNA 序列的差异为进一步了解 PMMoV 的感染和发病机制提供了理论价值。
