Mitochondria are highly pleomorphic, undergoing rounds of fission and fusion. Mitochondria are essential for energy conversion, with fusion favouring higher energy demand. Unlike fission, the molecular components involved in mitochondrial fusion in plants are unknown. Here, we show a role for the GTPase Miro2 in mitochondria interaction with the ER and its impacts on mitochondria fusion and motility. Mutations in AtMiro2’s GTPase domain indicate that the active variant results in larger, fewer mitochondria which are attached more readily to the ER when compared with the inactive variant. These results are contrary to those in metazoans where Miro predominantly controls mitochondrial motility, with additional GTPases affecting fusion. Synthetically controlling mitochondrial fusion rates could fundamentally change plant physiology by altering the energy status of the cell. Furthermore, altering tethering to the ER could have profound effects on subcellular communication through altering the exchange required for pathogen defence.

线粒体具有高度多形性，经历多轮裂变和融合。线粒体对于能量转换至关重要，聚变有利于更高的能量需求。与裂变不同，植物线粒体融合中涉及的分子成分尚不清楚。在这里，我们展示了 GTPase Miro2 在线粒体与 ER 相互作用中的作用及其对线粒体融合和运动的影响。 AtMiro2 GTPase 结构域的突变表明，活性变体会产生更大、更少的线粒体，与非活性变体相比，这些线粒体更容易附着到 ER 上。这些结果与后生动物中的结果相反，在后生动物中，Miro 主要控制线粒体运动，并有其他 GTP 酶影响融合。综合控制线粒体融合率可以通过改变细胞的能量状态从根本上改变植物生理学。此外，改变内质网的束缚可能通过改变病原体防御所需的交换而对亚细胞通讯产生深远的影响。