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干细胞种群维持和控制中的作用。由于干细胞在人类发育中至关重要，并在疾病治疗中具有潜在的用途，因此了解它们的工作原理是一个重要的公共卫生目标。为实验选择的生物是开花植物拟南芥，干细胞群体是茎顶端分生组织，它在胚胎中形成，是植物所有地上部分的来源，包括茎、叶和花。之所以选择这种植物，是因为它的干细胞特别容易进行实验--不仅有关于它们的基因活动模式以及它们相互交流机制的大量背景信息，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，而不需要任何侵入性的方法。拟议中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。众所周知，第一组细胞是位于分生组织顶部的中心区细胞，它分泌一种小蛋白，激活它们下面的细胞(肋骨分生组织细胞)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是由小信号蛋白决定的。拟议中的实验检验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。将使用的方法包括对涉及的细胞和蛋白质进行实时成像，分离涉及的基因和蛋白质，以及对与信号和受体一起工作的额外蛋白质进行遗传筛选，以控制干细胞的行为。公共卫生相关性：对植物干细胞群体的基本了解将揭示发育和干细胞行为的基本原则，因此最终将使组织工程成为可能，并将基因匹配的自我细胞用作治疗疾病和退化疾病所需细胞类型和身体器官的来源。植物发育本身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种植足够和营养丰富的食物的关键。

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.