Hernould M, Suharsono S, Litvak S, Araya A, Mouras A
Université de Bordeaux II, Laboratoire de Biologie Cellulaire, Talence, France.
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2370-4. doi: 10.1073/pnas.90.6.2370.
Cytoplasmic male sterility in plants is associated with mitochondrial dysfunction. We have proposed that a nuclear-encoded chimeric peptide formed by mitochondrial sequences when imported into the mitochondria may impair organelle function and induce male sterility in plants. A model developed to test this hypothesis is reported here. Assuming that the editing process in higher plant mitochondria reflects a requirement for producing active proteins, we have used edited and unedited coding sequences of wheat ATP synthase subunit 9 (atp9) fused to the coding sequence of a yeast coxIV transit peptide. Transgenic plants containing unedited atp9 exhibited either fertile, semifertile, or male-sterile phenotypes; controls containing edited atp9 or only the selectable marker gave fertile plants. Pollen fertility ranged from 31% to 75% in fertile plants, 10% to 20% in semifertile plants, and < 2% in male-sterile plants. Genetic and molecular data showed that the chimeric plasmid containing the transgene is inherited as a Mendelian trait. The transgenic protein is imported into the mitochondria. The production and frequency of semifertile or male-sterile transgenic plants conform to the proposed hypothesis.
植物中的细胞质雄性不育与线粒体功能障碍有关。我们提出，由线粒体序列形成的核编码嵌合肽在导入线粒体时可能会损害细胞器功能并诱导植物雄性不育。本文报道了一个为检验这一假设而建立的模型。假设高等植物线粒体中的编辑过程反映了产生活性蛋白的需求，我们使用了与酵母细胞色素c氧化酶亚基IV转运肽编码序列融合的小麦ATP合酶亚基9（atp9）的编辑和未编辑编码序列。含有未编辑atp9的转基因植物表现出可育、半不育或雄性不育表型；含有编辑过的atp9或仅含有选择标记的对照植株是可育的。可育植株的花粉育性为31%至75%，半不育植株为10%至20%，雄性不育植株小于2%。遗传和分子数据表明，含有转基因的嵌合质粒作为孟德尔性状遗传。转基因蛋白被导入线粒体。半不育或雄性不育转基因植物的产生和频率符合所提出的假设。
