Molecular characterization of two bipartite geminiviruses causing squash leaf curl disease: role of viral replication and movement functions in determining host range.
Molecular characterization of two bipartite geminiviruses causing squash leaf curl disease: role of viral replication and movement functions in determining host range.
复制标题
引起南瓜卷叶病的两种二分双生病毒的分子特征：病毒复制和运动功能在确定宿主范围中的作用。
DOI：
10.1016/0042-6822(91)90010-9
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发表时间：
1991
期刊：
影响因子：
3.7
通讯作者：
Lazarowitz,SG
中科院分区：
文献类型：
--
作者：
Lazarowitz,SG
两种不同但高度同源的两部分双生病毒的基因组已在南瓜曲叶病田间病株的提取液中被鉴定和克隆。这两种南瓜曲叶病毒(SqLCV)具有共价闭合的环状单链DNA基因组，具有与其他粉虱传播双生病毒相同的两部分组分组织特征。利用病毒制剂或克隆的病毒基因组组分在不同的潜在寄主植物上进行的侵染性研究表明，这两个SqLCV具有不同的寄主范围表型，这可以通过不同病毒基因组组分之间的特定相互作用来解释，这些相互作用影响了病毒在植物中的复制和系统运动。对农杆菌接种的叶盘的分析表明，限制性病毒的复制在非限制性病毒的反式转录中被拯救，这为田间经常在特定寄主中发现的病毒DNA组分的混合物提供了解释。对这两个SqLCV共同区域的序列分析发现，与非限制性病毒相比，限制性病毒存在13个碱基的缺失，这表明潜在的序列变化可能与它们的宿主范围表型差异有关，并加强了基于对它们密切进化关系的杂交研究的结论。在最初的田间南瓜中还发现了一个有缺陷的病毒成分，它似乎干扰了限制的SqLCV在其正常允许的宿主中的移动，并解释了观察到的这种病毒宿主范围变化的另一个方面。
The genomes of two distinct, but highly homologous, bipartite geminiviruses have been identified in and cloned from extracts of squash leaf curl diseased field squash. These two squash leaf curl viruses (SqLCVs) have covalently closed, circular single-stranded DNA genomes with the same bipartite component organization characteristic of other whitefly-transmitted geminiviruses. Infectivity studies using virus preparations or cloned viral genomic components on different potential host plants demonstrated that these two SqLCVs have different host range phenotypes which can be explained by specific interactions among the different viral genomic components that act to influence viral replication and systemic movement in the plant. Analysis ofAgrobacterium-inoculated leaf discs demonstrated that replication of the restricted virus was rescued intransby the nonrestricted virus, providing an explanation for the mixtures of viral DNA components often found in particular hosts in the field. Sequence analysis of the common regions of these two SqLCVs identified a 13-base deletion in the restricted virus as compared to the nonrestricted virus, suggesting a potential sequence alteration likely to be involved in their host range phenotypic differences and strengthening the conclusion based on hybridization studies of their close evolutionary relationship. Also identified in the original field squash was a defective viral component which appeared to interfere with movement of the restricted SqLCV in its normally permissive hosts and accounted for another aspect of host range variation observed for this virus.