Mitochondria play a significant role in plant cytoplasmic male sterility (CMS). In our previous study, mitochondrial complex I genes, nad4, nad5, and nad7 showed polymorphisms between the transgenic CMS line M2BS and its wild type M2B. The sterility mechanism of the M2BS at cytological, physiological, biochemical, and molecular level is not clear. Cytological observation showed that the anthers were light yellow, fissured, invalid in KI-I2, and full of irregularly typical abortion pollen grains in M2BS. Transmission electron microscopic (TEM) observation revealed no nucleus and degraded mitochondria with obscure cristae in anther cells of M2BS. The results of staining for H2O2 presented a large number of electron dense precipitates (edp) in intercellular space of anther cells of M2BS at anthesis. Moreover, the anther respiration rate and complex I activity of M2BS were significantly lower than those of wild type M2B during pollen development. Furthermore, RNA editing results showed only nad7 presented partially edited at 534th nucleotides. The expression of nad5 and nad7 revealed significant differences between M2B and M2BS. Our data demonstrated that mitochondrial structural degradation and complex I deficiency might be associated with transgenic CMS of rice.

中文翻译：

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线粒体结构的降解和复合物 I 的缺乏与水稻转基因 CMS 相关


线粒体在植物细胞质雄性不育（CMS）中发挥着重要作用。在我们之前的研究中，线粒体复合物 I 基因 nad4、nad5 和 nad7 在转基因 CMS 系 M2BS 与其野生型 M2B 之间表现出多态性。 M2BS在细胞学、生理学、生化和分子水平上的不育机制尚不清楚。细胞学观察表明，KI-I2花药淡黄色，有裂隙，无效，M2BS充满不规则的典型败育花粉粒。透射电子显微镜（TEM）观察发现M2BS花药细胞无核，线粒体退化，嵴模糊。 H2O2染色结果显示，M2BS开花期花药细胞胞间隙内有大量电子致密沉淀(edp)。此外，在花粉发育过程中，M2BS的花药呼吸速率和复合物I活性显着低于野生型M2B。此外，RNA编辑结果显示仅nad7在第534个核苷酸处出现部分编辑。 nad5和nad7的表达揭示了M2B和M2BS之间的显着差异。我们的数据表明，线粒体结构退化和复合物 I 缺乏可能与转基因水稻的 CMS 相关。