权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Studies on Molecular Breeding by Functional Analysis of Rice Mitochondrial Genome

水稻线粒体基因组功能分析的分子育种研究

基本信息

批准号：
05404007
负责人：
HIRAI Atsushi
金额：
$ 21.44万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05404007/
关键词：
Gene expression Mitochondrial genome Rice transcription 転写地図反復配列 PRS

项目摘要

The mitochondrial genomes of higher plants are much larger and more complex than those of other eukaryotic organisms. The structural complexity of the genomes has been associated with rearrangements among repeated sequences and the presence of many chloroplast-derived sequences. Following evidence shows the mode of gene expression in the mitochondrial genome of rice is also complex and flexible.Using in vitro capping/ribonuclease protection experiments and primer extension analyzes, we identified the transcription initiation sites of mitochondrial genes. The alignment of sequences surrounding the initiation sites of genes revealed a conserved sequence motif, particularly CRTA motif.The two gene clusters rps3-rpl16 and nad3-rps12 are separated from each other and are expressed as the individual transcription units in many plants. However, the four genes were located within a region of 6kbp in rice mitochondria, and all four genes were co-transcribed.The 76 bp sequence found in the upstream region of rrn26 is duplicated in the upstream region of trnfM.It was demonstrated that the transcription of trnfM and rrn26 starts from these sequences in the upstream regions of the respective genes.A chloroplast-derived tRNA gene, trnH was transcribed in rice mitochondria using mitochondrial specific promoter sequence. On the other hand, the mitochondrial specific gene, nad9 was transcribed together with the chloroplast-derived sequence. It shows a chloroplast-derived sequence is utilized as a promoter for nad9.

高等植物的线粒体基因组比其他真核生物的线粒体基因组更大、更复杂。基因组的结构复杂性与重复序列之间的重排和许多叶绿体衍生序列的存在有关。以下证据表明水稻线粒体基因组中的基因表达模式也是复杂而灵活的。通过体外加帽/核糖核酸酶保护实验和引物延伸分析，我们鉴定了线粒体基因的转录起始位点。基因起始位点周围的序列比对揭示了保守的序列基序，特别是 CRTA 基序。两个基因簇 rps3-rpl16 和 nad3-rps12 彼此分离，并在许多植物中表达为单独的转录单位。然而，这四个基因位于水稻线粒体中的6kbp区域内，并且所有四个基因都是共转录的。rrn26上游区域中发现的76bp序列在trnfM上游区域中重复。这表明trnfM和rrn26的转录从各自基因上游区域中的这些序列开始。叶绿体衍生的 tRNA 基因 trnH 使用线粒体特异性启动子序列在水稻线粒体中转录。另一方面，线粒体特异性基因 nad9 与叶绿体衍生序列一起转录。它显示叶绿体衍生的序列被用作 nad9 的启动子。