A MAP kinase cascade downstream of ERECTA and ERECTA-like receptors in regulating plant development

智力优点：除了细胞分化，阶段特异性和局部细胞分裂对于正常组织、器官和生物体的形成也是至关重要的。在生长和发育过程中高度协调的细胞分化和增殖事件说明了细胞间通讯的重要性，细胞间通讯是通过细胞表面受体/传感器和细胞内信号传导组分进行的。在拟南芥中，ERECTA（ER），一种受体样激酶，及其同源物（ERL 1和ERL 2）在这些过程中发挥重要作用。它们的突变改变了植物的结构和繁殖。与er或er/erl 1/erl 2突变体植物类似，MPK 3和MPK 6，两种拟南芥丝裂原活化蛋白激酶（MAPK）或其上游MAPKK（MKK 4/MKK 5）的功能丧失也导致类似的表型。遗传分析表明，获得功能的MAPKK转基因可以拯救功能丧失的er或er/erl 1/erl 2突变体，这表明MPK 3/MPK 6在ER/ERL 1/ERL 2受体下游发挥功能。本项目的目标是了解MPK 3/MPK 6在局部细胞分裂调节中的分子机制。此外，将鉴定MKK 4/MKK 5-MPK 3/MPK 6模块上游的MAPKK激酶。将采用一种组合方法来实现这些目标。明确ER/ERL 1/ERL 2受体样激酶下游的特异性MAPK级联反应对我们理解细胞间通讯是很重要的。ER/ERL 1/ERL 2通路中MPK 3/MPK 6下游新组分的鉴定将揭示其在局部细胞分裂中作用的分子机制。该研究还将揭示MPK 3和MPK 6的功能多样性和信号特异性。该项目产生的工具将有广泛的应用，并将与其他团体分享。 更广泛的影响：该项目将采用综合方法来了解MAPK级联及其上游受体样激酶在协调植物发育中的作用，这将为学生和博士后研究员提供良好的培训环境。使用综合方法研究生物现象的培训对后基因组生物学的发展至关重要。除了科学方法，学生/博士后还将接受道德和职业发展方面的培训。学生（包括研究生和本科生）和博士后从代表性不足的群体将积极参与机构计划，接触到少数民族招募。参与该项目的博士后将遵循由实验室研究培训，学生指导经验和专业发展培训支持的职业发展计划。了解植物生长和发育的信号转导途径和重要调控因子的识别可以积极影响食品/饲料/生物燃料生产，这对维持不断增长的世界人口至关重要。

Intellectual merit: Besides cell differentiation, stage-specific and localized cell division is also critical to the formation of normal tissues, organs, and organisms. The highly coordinated cell differentiation and proliferation events during growth and development illustrate the importance of cell-cell communication, which is carried out by cell surface receptors/sensors and intracellular signaling components. In Arabidopsis, ERECTA (ER), a receptor-like kinase, and its homologs (ERL1 and ERL2) play important roles in these processes. Their mutation alters both the architecture and the reproduction of the plant. Similar to er or er/erl1/erl2 mutant plants, loss-of-function of MPK3 and MPK6, two Arabidopsis mitogen-activated protein kinases (MAPKs), or their upstream MAPKKs (MKK4/MKK5) also resulted in similar phenotypes. Genetic analysis demonstrated that the gain-of-function MAPKK transgene can rescue the loss-of-function er or er/erl1/erl2 mutants, suggesting that MPK3/MPK6 function downstream of ER/ERL1/ERL2 receptors. The goal of this project is to understand the molecular mechanism underlying the function of MPK3/MPK6 in the regulation of localized cell division. In addition, the MAPKK kinase(s) upstream of the MKK4/MKK5-MPK3/MPK6 module will be identified. A combinatory approach will be employed to reach these goals. Defining a specific MAPK cascade downstream of the well-characterized ER/ERL1/ERL2 receptor-like kinases is important to our understanding of cell-cell communication. The identification of new components downstream of MPK3/MPK6 in the ER/ERL1/ERL2 pathway will reveal the molecular mechanism underlying their role in the localized cell division. The research will also reveal the functional diversity and signaling specificity of MPK3 and MPK6. The tools generated in this project will have broad applications and will be shared with other groups. Broader impacts: This project will use an integrative approach to understand the roles of a MAPK cascade and its upstream receptor-like kinases in coordinating plant development, which will serve as an excellent training environment for students and postdoctoral fellows. Training in use of integrative approaches to the study of biological phenomena is critical to the advancement of post-genome biology. In addition to scientific methodology, students/post-docs will also receive training in ethics and career development. Students (both graduate and undergraduate) and post-docs from under-represented groups will be actively recruited by participating in institutional programs that reach out to minorities. Post-docs involved in the project will follow a career development plan supported by the research training in the lab, student mentoring experiences, and professional development training. Understanding the signal transduction pathways and the identification of important regulators of plant growth and development could positively impact food/feed/biofuel production, which is important to sustain the increasing world population.