A study on behavior of the plastids during the sexual reproduction of higher plants.

高等植物有性生殖过程中质体行为的研究。

• 批准号: 01540577
• 负责人: HASHIMOTO Haruki
• 金额: $ 1.28万
• 依托单位: Department of Biology, College of Arts and Sciences, The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01540577/
• 关键词: Plastid; Chloroplast; Mitochondria; Egg plant; Embryo sac; Egg apparatus; Nucleoid; Electron microscopy; 重複受精

Changes in morphology and the number of plastids and mitochondria in unfertilized egg cells of Solanum melongena before and after pollination were described, using techniques of electron microscopy of serial sections and three-dimensional reconstruction.The egg cell in a mature embryo sac examined contained 30 plastids and 137 mitochondria. Half the plastids were surrounding the egg nucleus which was located at the chalazal end of the cell. In contrast, only 15% of the mitochondria were perinuclear.After pollination but before reaching of the pollen tube to the egg apparatus, marked changes were observed on the number, configuration and distribution of both plastids and mitochondria in the egg cell. The number of the plastids decreased to 14 or at most 19. The volume of the plastids on average increased and five of them were branched and elongated in configuration. Nucleoids of the plastids in the egg cell were difficult to detect in the section by electron microscopy either before or after pollination. The change was more drastic with the mitochondria. The number of the mitochondria decreased to 17 or at most 22. Seven of them were 'giant mitochondria' of extremely elongated, branched and entangled configuration. In these mitochondria nucleoids were conspicuously observed.The observations suggest that reduction of the number of the plastids and mitochondria occurs in the egg cell just before fertilization. It is most likely that this may be caused by organelle fusion.

利用电镜连续切片和三维重建技术，观察了茄子授粉前后未受精卵细胞中质体和线粒体的形态和数量变化，成熟胚囊中的卵细胞含有30个质体和137个线粒体。卵核位于细胞合点端，有一半质体围绕卵核。授粉后，在花粉管到达卵器之前，卵细胞中质体和线粒体的数量、形态和分布都发生了明显的变化。质体数目减少到14个或最多19个。质体的体积平均增加，其中五个是分支和伸长的配置。无论授粉前还是授粉后，在电镜下都很难观察到卵细胞中质体的类核。线粒体的变化更为剧烈。线粒体数目减少到17个或最多22个。其中七个是“巨大的线粒体”，具有极其细长、分支和纠缠的结构。这些观察结果表明，在受精前，卵细胞中质体和线粒体的数量减少。这很可能是由细胞器融合引起的。