The construction of plasmids suitable for searching important rice genes.

为了克隆未知但在农业上有用的基因，我们构建了一个适合转移dna介导的插入突变的质粒。它有一个35S启动子和一个在植物细胞中活跃的氯霉素乙酰转移酶基因，以及一个在细菌细胞中活跃的复制起点和一个氨苄西林抗性基因。我们试图用粒子枪将这个7.6 kb长的质粒转化到水稻培养细胞中，但我们无法获得转化子。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大得多，也复杂得多。然而，已鉴定的基因数量有限。我们推测线粒体DNA编码了更多的活性基因，并在水稻线粒体DNA中搜索了尚未确定的重要基因。首先，我们构建了水稻线粒体基因组的转录图谱。然后我们确定了RNA转录但基因未被识别的区域的核苷酸序列。我们用这种方法找到了nad9， NADH脱氢酶亚基9的基因。

In order to clone unknown but agriculturally useful genes, we have constructed a plasmid suitable for transferred-DNA-mediated insertional mutagenesis. It has a 35S promoter and a chloramphenicol acetyl transferase gene which are active in plant cells, and a replication origin and a ampicillin resistant gene which are active in bacterial cells. We tried to transform this 7.6 kb long plasmid into rice culture cells by a particle gun, but we could not obtain transformants. The mitochondrial genomes of higher plants are much larger and more complex than those of other eukaryotic organisms. However, number of identified genes are limited. We speculated that mitochondrial DNA codes more active genes and searched unidentified important genes in rice mitochondrial DNA.First, we constructed a transcription map of the mitochondrial genome from rice. Then we determined nucleotide sequence the area in where the RNA is transcribed but genes are not identified. We found nad9, the gene for NADH dehydrogenase subunit 9, by this method.