The possibility of nitrogen fixation by genetic improving the rice chioroplast

为了观察活细胞内质体的形态，采用粒子轰击法将GFP与水稻叶绿体核糖体蛋白L12-1传递肽的融合基因（cpTP-GFP）导入水稻表皮细胞。共聚焦激光扫描显微镜显示GFP荧光定位在质体中。cpTP-GFP信号与叶绿素自身荧光信号具有特异性匹配。此外，还有一些细胞的质体具有不同长度的突起，但没有叶绿素，即“基质”。在少数细胞中，间质几乎连接了一个细胞内所有的质体，形成一个泛细胞质网络。基质连接的一个看似合理的功能是交换质体成分，如蛋白质。这将统一或协调细胞中的所有质体，并通过减少对细胞核的需求，有助于细胞的生产力。为了确定基质介导的质体融合是否发生，我们用一种质体靶向荧光蛋白（Kaede）标记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。即使在光转化两天后，也没有观察到过渡到表明质体融合的均匀颜色（黄色）。

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.