In depth characterization of organelle tubulation phenomenon using plastid stromules

点击翻译按钮获取中文摘要

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.