Molecular Mechanism of EMF1-Mediated Floral Repression in Arabidopsis

胚胎花（EMF）基因EMF1和EMF2是营养发育和生殖发育所必需的。14个功能丧失突变体被分离出来，大多数在我们的实验室被鉴定。突变体在萌发时开花，EMF活动的调节产生了早期开花的可育植物和花序结构改变的植物。克隆EMF基因发现，EMF1编码一个可能的转录调节因子，而EMF2编码一个Polycomb Group （PcG）蛋白同源物。基因表达研究表明，EMF蛋白对花和种子程序施加全局抑制，从而允许发芽后的营养发育。本研究旨在探讨emf1介导的花抑制的分子机制。本研究的长期目标是阐明植物发育的表观遗传机制。目的是进一步表征EMF1和几种与EMF1相互作用的蛋白质的功能，并确定EMF1的靶基因。免疫学或标记蛋白检测将用于研究EMF1可能的转录后调控，并开发用于EMF1蛋白检测和分离的工具。EMF1负责蛋白与EMF1相互作用蛋白相互作用的区域将被表征。一种诱导系统将用于激活EMF1突变体中的EMF1，并识别EMF1的早期靶标。发现一种能使花器官身份或其他早期靶基因失活的蛋白质复合物，将有助于深入了解营养发育过程中花的抑制机制。了解emf1介导的开花抑制的分子机制将有助于设计在特定时间开花的作物，从而增加其种植的地理范围。一名博士后和一名研究生将参与拟议的研究。博士后在具备完成大部分实验的必要技能的同时，还将在研究过程中学习新的概念和技术。研究生将接受各种分子和免疫学技术的培训。他们都将参与实验的设计，并通过口头和书面报告阐明实验结果。通常，不同背景的本科生都会参与我们的研究项目。代表性不足的学生可以通过全校范围的暑期研究机会计划和本科生研究机会计划获得我们的研究项目。

0236399SungThe EMBRYONIC FLOWER (EMF) genes, EMF1 and EMF2, are required for vegetative development and involved in reproductive development. Fourteen loss-of-function mutants were isolated and most were characterized in our laboratory. The mutants flower upon germination and modulation of EMF activities generated fertile plants that flower early and plants that show altered inflorescence architecture. Cloning the EMF genes revealed that EMF1 encodes a putative transcriptional regulator and EMF2 a Polycomb Group (PcG) protein homolog. Gene expression studies suggest that EMF proteins exert global repression of the flower and seed program, thereby allowing vegetative development upon germination. The proposed research aims to investigate the molecular mechanism of EMF1-mediated floral repression. The long-term goal of the proposed research is to elucidate the epigenetic mechanism underlying plant development.The objectives are to further characterize the function of EMF1 and several proteins that interact with EMF1, and identify the target genes of EMF1. Immunological or tagged-protein detection will be employed to study possible posttranscriptional regulation of EMF1 and develop tools for EMF1 protein detection and isolation. The regions of EMF1 responsible for protein-protein interaction with the EMF1-interacting proteins will be characterized. An inducible system will be used to activate EMF1 in emf1 mutants and identify early targets of EMF1. Finding a protein complex that inactivates the floral organ identity or other early target genes will provide insights into the mechanism of floral repression during vegetative development. Understanding of the molecular mechanism of EMF1-mediated floral repression would enable the design of crops that flower at specific time, thereby increasing the geographical range of their cultivation. A postdoctoral fellow and a graduate student will be involved in the proposed research. While the postdoctoral fellow has the necessary skills to carry out most of the experiments proposed, he will also learn new concepts and techniques during the course of the proposed research. The graduate student will be trained in a variety of molecular and immunological techniques. Both will be involved in the design of the experiments and articulation of experimental findings through oral and written presentations. Typically, undergraduate students of diverse backgrounds are involved in our research projects. Underrepresented students have access to our research projects through the campus-wide Summer Research Opportunity Programs and Undergraduate Research Opportunity Programs.