Lauer M, Knudsen C, Newton K J, Gabay-Laughnan S, Laughnan J R
Division of Biological Sciences, University of Missouri, Columbia 65211.
New Biol. 1990 Feb;2(2):179-86.
The nonchromosomal stripe (NCS) mutations of maize are a set of maternally inherited mutations that result in reduced plant growth and lowered reproductive capacity. NCS6 mutants are characterized by stunted growth, yellow stripes on leaves, and sectors of aborted kernels on ears. The heteroplasmic NCS6 striped plants carry both partially deleted and normal versions of the mitochondrial cytochrome oxidase subunit 2 (cox2) gene and have low levels of cox2 transcripts when compared with nonstriped control plants. Other tested mitochondrial genes and their transcripts appear to be unaltered in NCS6 plants. The level of COXII protein is also specifically reduced in the striped plants relative to that of control plants. In the NCS6 mutant mitochondrial genome, a portion of the first exon of the cox2 gene is deleted along with the 5' flanking region. The formation of the defective cox2 gene appears to have involved a recombination event between 31-bp repeats.
玉米的非染色体条纹（NCS）突变是一组母系遗传突变，会导致植株生长减缓以及繁殖能力降低。NCS6突变体的特征是生长发育不良、叶片出现黄色条纹以及果穗上有败育籽粒区域。异质的NCS6条纹植株同时携带部分缺失和正常版本的线粒体细胞色素氧化酶亚基2（cox2）基因，与无条纹的对照植株相比，其cox2转录本水平较低。其他经过检测的线粒体基因及其转录本在NCS6植株中似乎未发生改变。相对于对照植株，条纹植株中COXII蛋白的水平也有特异性降低。在NCS6突变体的线粒体基因组中，cox2基因第一个外显子的一部分连同5'侧翼区域一起被删除。有缺陷的cox2基因的形成似乎涉及31个碱基对重复序列之间的重组事件。
