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

Establishment of New Breeding Science by Biotechnology

利用生物技术建立新育种科学

基本信息

批准号：
08306001
负责人：
HIRAI Atsushi
金额：
$ 12.29万
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：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

Many findings for new breeding sciences were reported. One of the important findings was the stability of plant mitochondrial genome. Mitochondrial sequence that contains the chloroplast-derived trnH gene has been highly conserved in the region around one terminus of the junction between chloroplast-derived and mitochondrion-specific sequences in most of the gramineous plant analyzed. The results of RT-PCR, northern hybridization, in vitro capping and ribonuclease protection experiments show that the chloroplast-derived trnH gene is transcribed from a promoter that is located in the mitochondrion-specific sequence. Gene expression in this region seems to be correlated with the conservation of the sequence at the junction between chloroplast-derived fragment and the mitochondrion-specific sequence.Thus, expression of chloroplast-derived tRNA genes is important for the stability of plant mitochondrial genome. Previous investigations located nine of the genes for rice tRNAs on chloroplast-derived sequences in mitochondrial DNA.We examined whether these genes were also transcribed in the rice mitochondria. Northern blot hybridization revealed that seven of these genes (trnC, trnF, trnH, trnM, trnN, trnS and trnW) are transcribed and are precisely processed to mature tRNAs. One of the other two genes (trnP) is transcribed but cannot be processed efficiently, and the other (trnR), which has 100% identity to the original plastid tRNA_<Arg> gene, is not transcribed in rice mitochondria. These results suggest that seven of the nine pt-derived tRNAs may be utilized for biosynthesis of protein in plant mitochondria, and support for the stability of plant mitochondrial genome.

报道了许多新育种科学的发现。重要发现之一是植物线粒体基因组的稳定性。在大多数分析的禾本科植物中，含有叶绿体来源的 trnH 基因的线粒体序列在叶绿体来源和线粒体特异性序列之间的连接处的一末端周围区域高度保守。 RT-PCR、Northern杂交、体外加帽和核糖核酸酶保护实验的结果表明，叶绿体来源的trnH基因是从位于线粒体特异性序列中的启动子转录的。该区域的基因表达似乎与叶绿体来源的片段和线粒体特异性序列之间的连接处序列的保守性相关。因此，叶绿体来源的tRNA基因的表达对于植物线粒体基因组的稳定性很重要。先前的研究在线粒体 DNA 中叶绿体衍生的序列上定位了 9 个水稻 tRNA 基因。我们检查了这些基因是否也在水稻线粒体中转录。 Northern 印迹杂交显示其中 7 个基因（trnC、trnF、trnH、trnM、trnN、trnS 和 trnW）被转录并被精确加工成成熟的 tRNA。另外两个基因之一（trnP）被转录，但无法有效加工，另一个（trnR）与原始质体tRNA_<Arg>基因具有100%同一性，在水稻线粒体中不转录。这些结果表明，9 个 pt 衍生的 tRNA 中的 7 个可用于植物线粒体中蛋白质的生物合成，并支持植物线粒体基因组的稳定性。