MODIFICATIONS OF THE TOBACCO MOSAIC-VIRUS COAT PROTEIN GENE AFFECTING REPLICATION, MOVEMENT, AND SYMPTOMATOLOGY
MODIFICATIONS OF THE TOBACCO MOSAIC-VIRUS COAT PROTEIN GENE AFFECTING REPLICATION, MOVEMENT, AND SYMPTOMATOLOGY
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DOI：
10.1094/phyto-78-783
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发表时间：
1988-06-01
期刊：
影响因子：
3.2
通讯作者：
GRANTHAM, GL
中科院分区：
文献类型：
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作者：
DAWSON, WO;BUBRICK, P;GRANTHAM, GL
通过对烟草病毒（tobacco virus，TMV）基因组（pTMV 204）的cDNA进行改造，并通过体外转录，获得了一系列外壳蛋白基因插入和/或缺失的突变体。所有的突变体作为游离RNA病毒繁殖，并从细胞到细胞在接种的Xanthi烟草叶片，虽然突变体建立系统感染效率低于野生型TMV。这包括去除了整个外壳蛋白基因的突变体，将28个核苷酸延伸到3“-非翻译区的缺失，以及含有细菌氯霉素乙酰转移酶基因取代外壳蛋白基因的突变体。大多数的突变体产生外壳蛋白相关的多肽在体内，虽然在接种的叶片中发现的蛋白质的大小和数量在不同的突变体之间变化很大。一般来说，含有正常外壳蛋白羧基末端的多肽倾向于以更大的量积累。三种类型的反应，观察到在muscum感染Xanthi烟草：没有症状，变黄，和坏死。大多数不产生或产生少量外壳蛋白的突变体不能诱导症状。保留外壳蛋白羧基末端的突变体诱导黄化症状。所有的突变体，包括那些完全缺乏外壳蛋白基因诱导的局部病变Xanthi-nc。两个突变体也诱导Xanthi烟草以及几乎所有的寄主植物的坏死局部病变。这些结果表明，TMV外壳蛋白基因在感染过程中具有多功能的作用，包括抑制、症状表达和抗性基因的差异诱导。
A series of tobacco virus (TMV) mutants with insertions and/or deletions in the coat protein gene were made by modification of the cDNA of the genome (pTMV204) followed by in vitro transcription. All mutants multiplied as free-RNA viruses and moved from cell to cell in inoculated leaves of Xanthi tobacco, although the mutants established systemic infections less efficiently than wild-type TMV. This included mutants that had the entire coat protein gene removed, deletions that extended 28 nucleotides into the 3''-nontranslated region, as well as a mutant containing the bacterial chloramphenicol acetyltransferase gene substituted for the coat protein gene. Most of the mutants produced coat protein-related polypeptides in vivo, although the size and amount of protein found in inoculated leaves varied considerably among different mutants. In general, polypeptides that contained the normal coat protein carboxyl terminus tended to accumulate in greater amounts. Three types of responses were observed in mutant-infected Xanthi tobacco: no symptoms, yellowing, and necrosis. Most mutants that produced no or low amounts of coat protein failed to induce symptoms. The mutants that retained the carboxyl terminus of the coat protein induced yellowing symptoms. All mutants including those completely lacking the coat protein gene induced local lesions in Xanthi-nc. Two mutants also induced necrotic local lesions in Xanthi tobacco as well as almost all host plants tested. These results demonstrate that the TMV coat protein gene has a multifunctional role during infection that includes encapsidation, symptom expression, and differential elicitation of resistant genes.