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Analysis of virus-host interaction in multiplication of tobacco mosaic virus

烟草花叶病毒繁殖过程中病毒与宿主相互作用的分析

基本信息

批准号：
63580201
负责人：
MESHI Tetsuo
金额：
$ 1.73万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63580201/
关键词：
tobacco mosaic virus Tm-1 gene Tm-2 gene in vitro transcription replication cell-to-cell movement resistance reaction nucleotide sequence 試験官内転写系塩基配列の決定

项目摘要

Resistance-breaking strains named Lta1 and Ltb1 can overcome the resistance conferred by the Tm-1 and Tm-2 genes in tomato, respectively. To understand the resistance mechanisms and to get hints for normal process of multiplication of tobacco mosaic virus (TMV), mutations of Lta1 and Ltb1 responsible for overcoming the resistance were determined.From the nucleotide sequence comparison and subsequent reverse- genetic analysis, It was found that two base substitutions in the 130k/180k protein genes resulting in amino acid changes from Gln(979) to Glu and from His(984) to Tyr are important for the ability to overcome the Tm-1 resistance. Further analysis of other resistance-breaking strains and pseudorevertants suggested that an electrostatic interaction is involved in the resistance mechanism. Analysis in protoplasts supported that the resistance works in the course of replication. This is consistent with the involvement of the 130k and 180k proteins in replication.In the case of Ltb1, it was found that two base substitutions in the 30k protein gene resulting in amino acid changes from Cys(868) to Phe and from Glu(133) to Lys are involved in the property to overcome the Tm-2 resistance. Since the 30k protein is known to be involved in cell-to-cell movement, and since the mutations occur in well-conserved regions in the 30k protein, the Tm-2 gene would seem to block the normal cell-to-cell movement.Analysis using in vitro generated mutants revealed that the coat protein gene encodes the determinant for induction of the hypersensitive response in plants with the N' gene. It is not necessary to be assembled into virus particles.

分别命名为Lta 1和Ltb 1的抗性破坏菌株可以克服番茄Tm-1和Tm-2基因所赋予的抗性。为了了解烟草花叶病毒（TMV）的抗病机制，并为TMV的正常增殖过程提供线索，本研究通过核苷酸序列比较和反向遗传分析，确定了TMV抗病基因Lta 1和Ltb 1的突变位点。结果发现，130 k/180 k蛋白基因中的两个碱基替换导致氨基酸从Gln（979）变为Glu和从His（984）变为Glu。对于克服Tm-1抗性的能力是重要的。对其他抗性破坏菌株和假回复突变体的进一步分析表明，静电相互作用参与了抗性机制。对原生质体的分析支持抗性在复制过程中起作用。在Ltb 1中，发现30 k蛋白基因中的两个碱基替换导致氨基酸从Cys（868）变为Phe和从Glu（133）变为Lys，这与克服Tm-2抗性的性质有关。由于已知30 k蛋白参与细胞间的运动，并且由于突变发生在30 k蛋白中的高度保守区域，Tm-2基因似乎阻断了正常的细胞间运动。使用体外产生的突变体进行的分析揭示，外壳蛋白基因编码具有N'基因的植物中诱导过敏反应的决定子。它不需要组装成病毒颗粒。