In depth characterization of organelle tubulation phenomenon using plastid stromules

荧光蛋白标记的细胞区室的生命细胞成像显示，细胞器表现出灵活的形态，可以在几秒钟内发生巨大变化。线粒体、过氧化物酶体和质体共同的形态学主题是管状膜延伸的形成。尽管它们的形成似乎受到严格的调控，但我们目前对它们在细胞活力中所起作用的了解非常有限，而且对这些小管所涉及的细胞过程几乎一无所知。根据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，我在博士期间筛选了质体，重点是质体小管（stromule）相关刺激。我发现葡萄糖和蔗糖是基质形成的特异性诱导剂，这表明基质与碳水化合物代谢有关。我的目标是通过拟南芥突变体和非代谢糖类似物进一步研究基质和碳水化合物代谢之间的联系。此外，我将测试转录谱容易获得的条件。通过这一点，我将讨论基质形成的遗传背景，EMS诱变筛选将补充遗传方法。在下一步中，我将扩大范围到线粒体和过氧化物酶体，并将评估基质相关刺激对这两个细胞器的影响。该项目最终将不仅有助于阐明间质形成的遗传背景，还将有助于将间质置于植物细胞的生理和代谢环境中。通过将范围扩大到线粒体和过氧化物酶体，我提出的工作有可能告诉我们真核细胞在不断受到众多环境压力挑战的情况下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.