Analysis of heterotrimeric G protein signaling in maize development

异源三聚体G蛋白信号传导控制广泛的发育和生理过程，包括细胞增殖和生长。过去十年的工作表明，植物中的G蛋白信号传导并不遵循动物系统中建立的经典范式。我最近鉴定和表征了玉米COMPACT PLANT 2（CT 2）基因，该基因编码异源三聚体蛋白的G-α亚基，为现在分析异源三聚体G蛋白信号传导的潜在分子机制提供了一个独特的切入点，这些机制仍然知之甚少。ct 2突变体表型的复杂性支持新出现的观点，即异源三聚体G蛋白信号转导参与许多不同的过程，并可能作为整合不同调控途径的枢纽。我的进一步结果表明，在植物和动物中，异源三聚体G蛋白在细胞中扮演着多种非经典的角色。从大量的准备工作开始，我将在这里解剖异源三聚体G蛋白信号在植物中如何整合细胞外信号感知与细胞内信号转导和细胞骨架动力学来控制细胞增殖和生长。我将首先分析G蛋白信号的网络结构，并特别询问BR信号是否以及如果是的话如何与异源三聚体G-α亚基交叉以控制植物高度，这是作物中主要的产量相关性状。在第二部分，我将探讨非典型的异源三聚体G蛋白在玉米中的功能，特别是在植物细胞骨架的调节。为了补充这两个部分，我将使用玉米遗传学的力量，以确定EMS诱导和天然存在的G-α介导的信号增强子和抑制子。最后，我将遵循功能基因组学方法，系统地识别和表征所有六个玉米G-γ亚基的突变体。这些互补的方法相结合，将使我能够系统地评估异源三聚体G蛋白信号在植物中的植物结构的组织方面。预期的数据不仅将为这一尚未深入研究的信号通路提供基本见解，还将提供有关作物改良的知识。因此，该项目也为我在科学领域的长期职业生涯和重新融入德国大学系统奠定了坚实的基础。

Heterotrimeric G protein signaling controls a wide range of developmental and physiological processes, including cell proliferation and growth. Work of the last decade has shown that G protein signaling in plants does not follow the classical paradigm established in animal systems. My recent identification and characterization of the maize COMPACT PLANT2 (CT2) gene, which encodes the G-alpha subunit of the heterotrimeric protein, provides a unique entry point to now analyze the underlying molecular mechanisms of heterotrimeric G protein signaling, which are still poorly understood. The complexity of the ct2 mutant phenotype supports the emerging view, that heterotrimeric G protein signaling is involved in many different processes and likely serves as a hub to integrate different regulatory pathways. Further results of mine suggest that in plants as in animals, heterotrimeric G Proteins serve multiple non-canonical roles in the cell. Starting from substantial preparatory work, I will dissect here how heterotrimeric G protein signaling in plants integrates extracellular signal perception with intracellular signal transduction and cytoskeleton dynamics to control cell proliferation and growth. I will start by analyzing the network structure of the G protein signaling and ask in particular whether and if so how BR signaling intersects with the heterotrimeric G-alpha subunit to control plant height, which is a major yield related trait in crops. In a second part, I will explore non-canonical heterotrimeric G protein function in maize, especially during the regulation of the plant cytoskeleton. To complement both parts, I will use the power of maize genetics to identify EMS induced and naturally occurring enhancer and suppressors of G-alpha mediated signaling. Finally, I will follow a functional genomics approach and systematically identify and characterize mutants in all six maize G-gamma subunits. The combination of these complementary approaches will allow me to systematically assess heterotrimeric G protein signaling in plants with respect to the organization of plant architecture. The expected data will not only provide fundamental insights into this not much explored signaling pathway but also deliver knowledge about crop improvement. With this, the project also represents a solid base for a long-term career in science and my reintegration into the German university system.