Ishikawa Kazuya, Kobayashi Makoto, Kusano Miyako, Numata Keiji, Kodama Yutaka
Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi, Japan.
Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
Plant Cell Rep. 2023 Mar;42(3):599-607. doi: 10.1007/s00299-023-02982-2. Epub 2023 Jan 27.
By using the organelle glue technique, we artificially manipulated organelle interactions and controlled the plant metabolome at the pathway level. Plant cell metabolic activity changes with fluctuating environmental conditions, in part via adjustments in the arrangement and interaction of organelles. This hints at the potential for designing plants with desirable metabolic activities for food and pharmaceutical industries by artificially controlling the interaction of organelles through genetic modification. We previously developed a method called the organelle glue technique, in which chloroplast-chloroplast adhesion is induced in plant cells using the multimerization properties of split fluorescent proteins. Here, we generated transgenic Arabidopsis (Arabidopsis thaliana) plants in which chloroplasts adhere to each other and performed metabolome analysis to examine the metabolic changes in these lines. In plant cells expressing a construct encoding the red fluorescent protein mCherry targeted to the chloroplast outer envelope by fusion with a signal sequence (cTP-mCherry), chloroplasts adhered to each other and formed chloroplast aggregations. Mitochondria and peroxisomes were embedded in the aggregates, suggesting that normal interactions between chloroplasts and these organelles were also affected. Metabolome analysis of the cTP-mCherry-expressing Arabidopsis shoots revealed significantly higher levels of glycine, serine, and glycerate compared to control plants. Notably, these are photorespiratory metabolites that are normally transported between chloroplasts, mitochondria, and peroxisomes. Together, our data indicate that chloroplast-chloroplast adhesion alters organellar interactions with mitochondria and peroxisomes and disrupts photorespiratory metabolite transport. These results highlight the possibility of controlling plant metabolism at the pathway level by manipulating organelle interactions.
通过使用细胞器黏合技术，我们人工操控了细胞器间的相互作用，并在途径水平上控制了植物代谢组。植物细胞的代谢活性会随环境条件的波动而变化，部分是通过细胞器排列和相互作用的调整来实现的。这暗示了通过基因改造人工控制细胞器间的相互作用，从而为食品和制药行业设计出具有理想代谢活性的植物的可能性。我们之前开发了一种名为细胞器黏合技术的方法，该方法利用分裂荧光蛋白的多聚化特性在植物细胞中诱导叶绿体-叶绿体黏附。在这里，我们培育了叶绿体相互黏附的转基因拟南芥植株，并进行了代谢组分析以检测这些植株系中的代谢变化。在表达通过与信号序列（cTP-mCherry）融合靶向叶绿体外膜的红色荧光蛋白mCherry编码构建体的植物细胞中，叶绿体相互黏附并形成叶绿体聚集体。线粒体和过氧化物酶体嵌入聚集体中，这表明叶绿体与这些细胞器之间的正常相互作用也受到了影响。对表达cTP-mCherry的拟南芥地上部分的代谢组分析显示，与对照植物相比，甘氨酸、丝氨酸和甘油酸的含量显著更高。值得注意的是，这些都是通常在叶绿体、线粒体和过氧化物酶体之间运输的光呼吸代谢物。总之，我们的数据表明叶绿体-叶绿体黏附改变了细胞器与线粒体和过氧化物酶体之间的相互作用，并破坏了光呼吸代谢物的运输。这些结果突出了通过操纵细胞器间的相互作用在途径水平上控制植物代谢的可能性。
