Development of Transformation System for Plant Mitochondria

线粒体是真核细胞进行有氧代谢的能量传递场所。能量传递是通过线粒体膜上的几种蛋白复合物进行的。这些复合体的遗传信息储存在细胞核和线粒体基因组中。因此，为了提高线粒体活性，不仅要转化核基因组，还要转化线粒体基因组，构建质粒DNA转化水稻线粒体DNA，利用定点突变技术将线粒体编码的cob基因突变为抗霉素基因。将突变的cob基因与atp1的启动子区和atp6的3'非翻译区一起克隆到pBSKS+质粒中。水稻线粒体中的质粒样DNA B4也被连接到质粒上，以加速质粒DNA在水稻线粒体中的复制。用粒子枪将该线粒体转化用质粒DNA导入水稻愈伤组织。然而，迄今尚未获得转化细胞。改良质粒的构建正在进行中。

Mitochondria are the sites of energy transduction in eukaryotic cells which carry out aerobic metabolism. Energy transduction is conducted by several kinds of peotein complexes in the mitochondrial membrane. Genetic information of these complexes are stored in the nuclear and mitochondrial genomes. Thus, mitochondrial as well as nuclear genome should be transformed in order to improve mitochondrial activity.Plasmid DNA was constructed to transform rice mitochondrial DNA.Mitichondrial coded cob gene was mutated to antimycin resistant form by the site directed mutagenesis. The mutated cob gene, together with promoter region of atpl and 3' non-translated region of atp6 were cloned into pBSKS+ plasmid. Plasmid like DNA,B4, in rice mitochondria was also connected to the plasmid in order to accelerate the replication of the plasmid DNA in rice mitochondria. This plasmid DNA for mitochondria transformation was introduced into rice calli by a particle gun. However, transformed cells were not obtained so far. Construction of the improved plasmid is in progress.