Genetic Determinants of Symptoms on Viral DNA Satellites
Genetic Determinants of Symptoms on Viral DNA Satellites
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病毒 DNA 卫星上症状的遗传决定因素
DOI：
10.1128/aem.01193-09
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发表时间：
2009-08-15
影响因子：
4.4
通讯作者：
Zhou, Xueping
中科院分区：
文献类型：
--
作者：
Ding, Chenjun;Qing, Ling;Zhou, Xueping
begomovirus - dna - β疾病复合物在其宿主中诱导不同的症状表型。为了研究表型差异的遗传决定因素，将烟草卷枝病毒(TbCSV)/TbCSV dna - β (TbCSB)和番茄黄卷叶病毒(TYLCCNV)/TYLCCNV dna - β (TYLCCNB)假重组病毒分别接种给烟草属和番茄植株，结果表明，TYLCCNB诱导了典型的静脉增厚和发育症状，而TbCSB仅轻微加重了叶片卷曲症状，无论使用何种辅助病毒。通过构建在两个卫星分子之间交换β C1编码区或AP的杂交卫星分子，进一步研究了dna编码的β C1和含有β C1基因富a区和假定的β C1启动子区（简称AP）的430个核苷酸片段在症状发展中的作用。TYLCCNB与TbCSB β C1的杂交体失去了引起静脉增厚和发生表型的能力。含有TYLCCNB β C1或AP片段的TbCSB杂种未能诱导特征性的静脉增厚和增粗。含有TbCSB AP片段的TYLCCNB杂交种产生小代，但小代数量少，小代大小减小。与TYLCCNB启动子的韧皮部特异性模式不同，TbCSB β C1基因上游的全长片段在转基因烟草植物中具有组成型β -葡糖醛酸酶表达模式。上述结果表明，dna编码的β - C1蛋白是症状的决定因素，但β - C1基因的启动子对症状的产生有影响。
Begomovirus-DNA-beta disease complexes induce different symptom phenotypes in their hosts. To investigate the genetic determinants of the phenotypic differences, Nicotiana spp. and tomato plants were inoculated with infectious clones of Tobacco curly shoot virus (TbCSV)/TbCSV DNA-beta (TbCSB) and Tomato yellow leaf curl China virus (TYLCCNV)/TYLCCNV DNA-beta (TYLCCNB) pseudorecombinants and showed that TYLCCNB induced characteristic vein-thickening and enation symptoms, while TbCSB only slightly exacerbated the leaf-curling symptoms, regardless of the helper virus being used. The roles of DNA-beta-encoded beta C1 and a 430-nucleotide fragment containing the A-rich region and the putative beta C1 promoter region of the beta C1 gene (referred to as AP) in symptom development were further investigated by constructing hybrid satellites in which the beta C1 coding region or AP was exchanged between the two satellite molecules. A TYLCCNB hybrid with TbCSB beta C1 lost the ability to elicit the vein-thickening and enation phenotypes. TbCSB hybrids containing the TYLCCNB beta C1 or AP fragment failed to induce the characteristic vein thickening and enations. A TYLCCNB hybrid having the TbCSB AP fragment produced the enations, but the number of enations was less and their sizes were reduced. Differently from the phloem-specific pattern of the TYLCCNB promoter, a full-length fragment upstream of the TbCSB beta C1 gene confers a constitutive beta-glucuronidase expression pattern in transgenic tobacco plants. The above results indicate that the DNA-beta-encoded beta C1 protein is the symptom determinant, but the promoter of the beta C1 gene has influence on symptom production.