Department of International Agricultural Technology and Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea.
Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea.
Virus Res. 2017 Oct 15;242:141-145. doi: 10.1016/j.virusres.2017.09.024. Epub 2017 Sep 29.
Broad bean wilt virus 2 (BBWV2, genus Fabavirus, family Secoviridae) has a wide host range and infects many economically important crops. Various isolates of BBWV2 have been identified from diverse host plants, and their molecular and biological characteristics have been investigated. In our previous study, we demonstrated that BBWV2 RNA2 contains a symptom determinant(s) capable of enhancing symptom severity by utilizing infectious full-length cDNA clones of two distinct strains of BBWV2, pBBWV2-PAP1 (a severe strain) and pBBWV2-RP1 (a mild strain). In the present study, to identify the symptom determinant(s) of BBWV2, we exploited disease responses of pBBWV2-PAP1- and pBBWV2-RP1-derived chimeric viruses and amino acid substitution mutant viruses in Nicotiana benthamiana and pepper (Capsicum annuum Quarri) and demonstrated that the movement protein (MP) encoded in BBWV RNA2 is the determinant of disease symptom severity in both plants. A single amino acid substitution in the MP was sufficient for changing symptom severity of BBWV2. Our finding provides a role for the MP as a symptom determinant in BBWV2 and increases the understanding of the basis of molecular interactions between host plants and BBWV2.
菜豆花叶病毒 2 号（BBWV2，属 Fabavirus 科，单链 RNA 病毒科）宿主范围广泛，可感染许多重要的经济作物。从不同的宿主植物中已鉴定出各种 BBWV2 分离株，并且已经研究了它们的分子和生物学特性。在我们之前的研究中，我们证明了 BBWV2 RNA2 包含一个症状决定因子（symptom determinant），该因子能够利用两种不同 BBWV2 株系（pBBWV2-PAP1，强毒株；pBBWV2-RP1，弱毒株）的全长感染性 cDNA 克隆来增强症状严重程度。在本研究中，为了鉴定 BBWV2 的症状决定因子（symptom determinant），我们利用 pBBWV2-PAP1 和 pBBWV2-RP1 衍生嵌合病毒和烟草原生质体（Nicotiana benthamiana）及辣椒（Capsicum annuum Quarri）中的氨基酸取代突变病毒的发病反应，证明了 BBWV RNA2 编码的移动蛋白（MP）是两种植物发病症状严重程度的决定因素。MP 中的单个氨基酸取代足以改变 BBWV2 的症状严重程度。我们的发现为 MP 作为 BBWV2 中的症状决定因子提供了作用，并增加了对宿主植物与 BBWV2 之间分子相互作用基础的理解。
