In depth characterization of organelle tubulation phenomenon using plastid stromules

对荧光蛋白标记的细胞室进行的生命细胞成像显示，细胞器显示出灵活的形态，这种形态可以在几秒钟内发生巨大变化。线粒体、过氧酶体和质体的一个共同的形态主题是形成管膜延伸。尽管它们的形成似乎受到严格的调控，但我们目前对它们对细胞活力的作用的了解非常有限，几乎不知道任何关于这些小管参与的细胞过程的知识。随着这些结构的功能可以通过识别它们所参与的过程来阐明的想法，我在我的博士学位期间筛选了叶绿体，寻找与叶绿体相关的刺激。我发现葡萄糖和蔗糖是球茎形成的特异性诱导剂，这表明球茎与碳水化合物代谢有关。我的目标是利用拟南芥突变体和非代谢糖类似物进一步研究球茎与碳水化合物代谢之间的联系。此外，我将测试转录配置文件容易获得的条件，以确定它们与频闪的相关性。通过这一点，我将阐述球茎形成的遗传背景，EMS突变筛查将补充遗传方法。下一步，我将把研究范围扩大到线粒体和过氧化物体，并将评估灯笼草相关刺激对这两个器官的影响。这个项目最终将有助于阐明灯笼草形成的遗传背景，也将有助于将灯笼草置于植物细胞的生理和代谢背景中。通过将研究范围扩大到线粒体和过氧化体，我的工作有可能告诉我们真核细胞在不断受到各种环境压力的挑战时，维持最佳亚细胞环境的机制。

Life cell imaging of fluorescent protein labeled cell compartments revealed that organelles show a flexible morphology, which can change dramatically within seconds. A morphologic theme common to mitochondria, peroxisomes and plastids is the formation of tubular membrane extensions. Although their formation appears to be tightly regulated our current knowledge about their role for cell viability is very limited and hardly anything is known about cellular processes these tubules are involved.Following the idea that the function of these structures can be elucidated by the identification of processes they are involved in, I screened during my PHD, focusing on plastids, for plastid tubule (stromule) relevant stimuli. I found glucose and sucrose to be specific inducers of stromule formation, suggesting a connection of stromules to carbohydrate metabolism.I aim to further investigate the suggested connection of stromules and carbohydrate metabolism by the use of Arabidopsis thaliana mutants and non-metabolizable sugar analogues. Furthermore I will test conditions for which transcription profiles are readily available for their stromule relevance. By this and I will address the genetic background of stromule formation and an EMS mutagenesis screen will complement the genetic approach. In a next step I will expand the scope to mitochondria and peroxisomes and will evaluate the effect of stromule relevant stimuli on these two organelles.This project ultimately will help not only to clarify the genetic background of stromule formation, but will also help to place stromules in the physiological and metabolic context of the plant cell. By expanding the scope to mitochondria and peroxisomes my proposed work has the potential of informing us about the mechanisms employed by eukaryotic cells for maintaining an optimal subcellular milieu despite being challenged constantly by numerous environmental stresses.