The complete nucleotide sequence and multipartite organization of the tobacco mitochondrial genome: comparative analysis of mitochondrial genomes in higher plants
The complete nucleotide sequence and multipartite organization of the tobacco mitochondrial genome: comparative analysis of mitochondrial genomes in higher plants
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DOI：
10.1007/s00438-004-1075-8
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发表时间：
2005-02-01
影响因子：
3.1
通讯作者：
Sugiura, M
中科院分区：
文献类型：
--
作者：
Sugiyama, Y;Watase, Y;Sugiura, M
烟草是研究双二倍体植物线粒体DNA（mtDNA）起源和线粒体与叶绿体在植物细胞各种功能中的遗传相互作用的重要模式系统。作为第一步，我们已经确定了完整的烟草mtDNA序列。线粒体DNA（mtDNA）分析结果表明，N. tabacum可以被认为是430，597 bp的主环（MC）。大量克隆的序列比较显示，有四类来源于同源重组的边界，这导致了一个多体组织与两个MC和六个亚基因组环。线粒体DNA（mtDNA）分析结果表明，N.烟草含有36个蛋白质编码基因、3个核糖体RNA基因和21个tRNA基因。在第一类中，我们确定了基因rps 1和psi rps 14，这是以前被认为是不存在于烟草mtDNA的基础上Southern分析。将烟草与拟南芥、甜菜、水稻和甘蓝型油菜的mtDNA进行了比较。由于五种被子植物之间的重复序列没有显示出同源性，因此可以认为这些重复序列是在被子植物进化过程中由每个物种独立获得的。5种被子植物mtDNA的基因序列和基因间隔区序列也存在较大差异，表明高等植物在进化过程中经历了基因组结构的多次重组。在保守的基因，相同的潜在保守的nonanucleotide-motif-type启动子只能假定为rrn 18-rrn 5在4个双子叶植物，这表明编码序列不一定移动的启动子后，重组的线粒体基因组。
Tobacco is a valuable model system for investigating the origin of mitochondrial DNA (mtDNA) in amphidiploid plants and studying the genetic interaction between mitochondria and chloroplasts in the various functions of the plant cell. As a first step, we have determined the complete mtDNA sequence of Nicotiana tabacum. The mtDNA of N. tabacum can be assumed to be a master circle (MC) of 430,597 bp. Sequence comparison of a large number of clones revealed that there are four classes of boundaries derived from homologous recombination, which leads to a multipartite organization with two MCs and six subgenomic circles. The mtDNA of N. tabacum contains 36 protein-coding genes, three ribosomal RNA genes and 21 tRNA genes. Among the first class, we identified the genes rps1 and psi rps14, which had previously been thought to be absent in tobacco mtDNA on the basis of Southern analysis. Tobacco mtDNA was compared with those of Arabidopsis thaliana, Beta vulgaris, Oryza sativa and Brassica napus. Since repeated sequences show no homology to each other among the five angiosperms, it can be supposed that these were independently acquired by each species during the evolution of angiosperms. The gene order and the sequences of intergenic spacers in mtDNA also differ widely among the five angiosperms, indicating multiple reorganizations of genome structure during the evolution of higher plants. Among the conserved genes, the same potential conserved nonanucleotide-motif-type promoter could only be postulated for rrn18-rrn5 in four of the dicotyledonous plants, suggesting that a coding sequence does not necessarily move with the promoter upon reorganization of the mitochondrial genome.