Development of Transformation System for Plant Mitochondria

线粒体是真核细胞中进行有氧代谢的能量传递部位。能量转导是通过线粒体膜上的几种人蛋白复合体进行的。这些复合体的遗传信息存储在核和线粒体基因组中。因此，为了提高线粒体的活性，必须同时对线粒体基因组和核基因组进行转化。构建了转化水稻线粒体DNA的质粒DNA，通过定点突变将线粒体编码的cob基因突变为抗霉素抗性的形式。将突变的cob基因与atp1启动子和atp6的3‘非翻译区一起克隆到pBSKS载体中。为了加速水稻线粒体中的复制，还将水稻线粒体中的B4等质粒连接到该质粒上。用粒子枪将线粒体转化质粒DNA导入水稻愈伤组织。然而，到目前为止还没有获得转化细胞。改进后的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.