Impact of intracellular organelle positioing on metabolic performance and stress tolerance of Arabidopsis plants

植物中枢代谢特别灵活，反映了植物为适应发育和环境变化而定期调整自身内部生理机能的需要。虽然代谢模型已经产生了对植物代谢网络的理解，但对调节和分配通量的策略的理解还不够好，无法解释植物可观察到的代谢多功能性。在翻译后水平，小分子相互作用、翻译后蛋白质修饰和动态物理蛋白质关联是当前代谢通量调节概念的基础。然而，代谢控制最古老的概念之一是将植物代谢划分为不同的细胞器。细胞器本身是可移动的，它们相对于另一个细胞器的位置是受调节的，并对外界条件作出反应。在这里，我们的目的是验证细胞器定位和代谢纳米结构域的产生结构细胞代谢景观，支持效率，并提供一个新的调控层的假设。结合三个实验室的互补专业知识，我们使用一种合成方法来操纵和监测拟南芥细胞内线粒体和叶绿体的定位。我们将改变最近发现的连接叶绿体和线粒体的糖酵解代谢的稳定性。我们将进一步利用遗传编码的SpyCatcher系统诱导控制细胞器关联。为了抵消相互作用，我们将把线粒体和叶绿体固定在不同的细胞膜系统上。为了探索细胞器定位对细胞代谢和植物性能的意义，我们将采用先进的代谢物谱、通量分析、遗传编码生物传感器以及表型分析，在不同的光合和光呼吸代谢状态下进行研究。我们将进一步将蛋白质生物传感器固定在细胞器和其他膜的表面，以评估细胞器的定位和结合如何影响代谢梯度和纳米环境。建立植物细胞器动态结构组织对调节代谢性能的意义。

Plant central metabolism is particularly flexible and reflects the need of plants to regularly modify their own internal physiology in response to developmental and environmental changes. While metabolic modelling has generated an understanding of the plant metabolic network, the strategies to regulate and allocate fluxes are not understood sufficiently well to account for the observable metabolic versatility of plants. At the posttranslational level, small molecule interaction, posttranslational protein modifications, and dynamic physical protein associations underpin current concepts of the regulation of metabolic fluxes. One of the oldest concepts of metabolic control, however, is compartmentation of plant metabolism into different organelles. The organelles themselves are mobile and their positioning relative to another is regulated and responsive to external conditions. Here, we aim to test the hypothesis that organelle positioning, and the generation of metabolic nano-domains structure the cellular metabolic landscape, support efficiency, and provide a novel layer of regulation. Combining the complementary expertise of three labs, we use a synthetic approach to manipulate and monitor the positioning of mitochondria and chloroplasts within Arabidopsis cells. We will alter the stability of a recently discovered glycolytic metabolon that physically links chloroplasts and mitochondria. We will further control organelle associations inducibly using the genetically encoded SpyCatcher system. To counteract interaction, we will anchor mitochondria and chloroplasts to different cellular membrane systems. To explore the significance of organelle positioning on cellular metabolism and plant performance we will employ advanced metabolite profiling, flux analyses and genetically encoded biosensors as well as phenotypic analyses, under different states of photosynthetic and photorespiratory metabolism. We will further immobilize protein biosensors on the surface of the organelles and other membranes to assess how organelle positioning and association shape metabolic gradients and nano-environments. The significance of dynamic structural organisation of plant cell organelles to adjust metabolic performance will be established.