The possibility of nitrogen fixation by genetic improving the rice chioroplast

利用基因枪法将绿色荧光蛋白(GFP)与水稻叶绿体核糖体蛋白L12-1转运肽(CPTP-GFP)融合基因导入水稻表皮细胞中，以观察活细胞中叶绿体的形态。激光共聚焦扫描显微镜显示GFP荧光定位于质体内，CPTP-GFP信号与叶绿素自发荧光信号特别匹配。此外，还有一些细胞含有不同长度的不同长度的突起，不含叶绿素，即“球茎”。在少数细胞中，种球连接了几乎所有的细胞质，呈现出泛细胞质网络。球茎连接的一个看似合理的功能是交换蛋白质等叶绿体成分。这将统一或协调一个细胞中的所有质体，通过减少对细胞核的需求，有助于提高细胞的生产率。为了确定是否发生了由球茎介导的质体融合，我们用质体靶向荧光蛋白(KEED)标记了洋葱表皮细胞中的质体，然后将细胞内一些质体的荧光从绿色改变为红色。即使在光转换两天后，也没有观察到表明叶绿体融合的均匀颜色(黄色)的转变。

In order to visualize the shapes of plastids in a living cell, a fusion gene of GFP with the transit peptide of rice chloroplast ribosomal protein L12-1 (cpTP-GFP) was introduced into rice epidermal cells by the particle bombardment method. Confocal laser scanning microscopy showed that the GFP fluorescence was localized in the plastids.The cpTP-GFP signals were matched specially with the signals of chlorophyll autofluorescence. In addition, there were some cells that had plastids with various lengths of protuberances without chlorophyll, i.e., "stromules". In a few cells, stromules connected almost all the plastids in a cell, appearing as a pan-cytoplasmic network. One plausible function of stromule connections is to exchange plastid components such as proteins. This would unify or coordinate all of the plastids in a cell and, by lessening the demands on the nucleus, contribute to the productivity of the cell.To determine whether fusion of plastids mediated by stromules occurs, we labeled plastids in onion epidermal cells with a plastid-targeted fluorescent protein (Kaede) and then altered the fluorescence of some of the plastids within a cell from green to red. No transition to a uniform color (yellow) indicating the fusion of plastids was observed, even two days after the photo-conversion.