Role of the CLAVATA1 Receptor Kinase in Plant Stem Cell Regulation

描述（由申请人提供）：拟议研究的长期目标是了解细胞间通讯在维持和控制干细胞群中的作用。由于干细胞在人类发育中具有核心重要性，并且在疾病治疗中具有潜在用途，因此了解它们如何工作是一个重要的公共卫生目标。选择用于实验的生物体是开花植物拟南芥，干细胞群是茎顶端分生组织，其在胚胎中形成并且是植物的所有地上部分（包括茎、叶和花）的来源。之所以选择这种植物，是因为它的干细胞特别适合实验-不仅有大量的背景信息，关于它们的基因活动模式，以及它们相互交流的机制，而且植物干细胞位于植物表面，这使得它们能够在活着的时候被观察到，并且没有任何侵入性的方法。所提出的实验旨在揭示一组植物干细胞与另一组植物干细胞交流的机制。已知第一组，即分生组织顶部的中心区细胞，分泌一种小蛋白，激活它们下面的细胞（肋分生组织细胞）中的受体蛋白。初步结果表明，受体蛋白的稳定性和细胞定位由小信号蛋白决定。拟议的实验研究了小信号蛋白调节其自身受体在附近细胞中的水平和位置的确切机制。所使用的方法包括对所涉及的细胞和蛋白质进行实时成像，分离所涉及的基因和蛋白质，以及对与信号和受体一起沿着工作以控制干细胞行为的其他蛋白质进行遗传筛选。公共卫生相关性：对植物中干细胞群体的基本理解将揭示发育和干细胞行为的基本原理，因此最终将使组织工程成为可能，并将遗传匹配的自身细胞用作治疗疾病和退行性疾病所需的细胞类型和身体器官的来源。植物本身的发育也具有直接的健康意义，因为植物是人类80%以上食物的来源。对植物生长和发育的深刻理解是我们未来为世界生产充足和营养食物的关键。

DESCRIPTION (provided by applicant): The long-term objective of the proposed research is to understand the role of cell-cell communication in the maintenance and control of stem cell populations. As stem cells are of central importance in human development, and are of potential use in disease treatments, understanding how they work is an important public health goal. The organism chosen for the experiments is the flowering plant Arabidopsis thaliana, and the stem cell population the shoot apical meristem, which forms in embryos and is the source of all of the above-ground parts of the plant, including stem, leaves, and flowers. This plant has been chosen because its stem cells are particularly amenable to experiment - not only is there a great deal of background information on their patterns of gene activity, and on the mechanisms by which they communicate with each other, but also plant stem cells are at the plant surface, which allows them to be observed while alive and functioning without any invasive methods. The experiments proposed are designed to reveal the mechanism by which one set of plant stem cells communicates with another. It is known that the first set, the central zone cells at the top of the meristem, secrete a small protein that activates a receptor protein in the cells under them (the rib meristem cells). Preliminary results have revealed that the stability and cellular location of the receptor protein are determined by the small signaling protein. The proposed experiments examine the exact mechanisms by which the small signaling protein regulates the level and location of its own receptor in nearby cells. The methods to be used include live imaging of the cells and proteins involved, isolation of the genes and proteins involved, and also genetic screens for additional proteins that work along with the signal and receptor to control stem cell behavior. PUBLIC HEALTH RELEVANCE: A fundamental understanding of stem cell populations in plants will reveal basic principles of development and stem cell behavior, and will therefore eventually enable tissue engineering, and the use of genetically matched self-cells as a source of needed cell types and bodily organs to cure diseases and degenerative conditions. Plant development itself is also of direct health significance, as plants are the source of more than 80% of human food. A profound understanding of plant growth and development is a key to our ability to grow sufficient and nutritious food for the world in the future.