ELF3 Regulation of Circadian Rhythm and Flowering in Arabidipsis

Meek-Wagner9808208早花3号(ELF3)基因是从拟南芥中克隆的，与现有数据库中的基因没有任何相似性。到目前为止的结果表明，ELF3是昼夜节律振荡器的新的关键调节因子，也是花序和花分生组织特征基因的调节因子。ELF3基因产物通过作为控制生物钟活动的光感知途径的一个组成部分来调节光周期的假设将得到验证。ELF3在控制花起始和花分生组织发育的遗传途径中的作用也将被研究。其具体目的是：1)表征ELF3转录和翻译的空间和时间调节2)创建和表征-发育和昼夜反应-各种通过使用内源ELF3调节序列过表达或异位表达ELF3的转基因株系，以及构成的、组织特异性的、可诱导启动子系统3)确定与ELF3基因功能相关的遗传途径，该基因功能调节拟南芥的花起始和分生组织特性。4)鉴定与ELF3相互作用的基因产物，以促进适当的昼夜反应和开花，并鉴定受ELF3功能调控的基因，可能是下游基因或昼夜节律自动调节的基因。本研究的长期目标是了解植物对日长变化的发育反应的分子机制。像花启动这样的反应很可能是由光感受途径控制的，这些光感受途径也影响植物的昼夜节律功能。将采用分子遗传学方法来了解拟南芥开花的光周期控制，重点是ELF3基因，该基因是在本实验室分离和鉴定的。以往的研究结果表明，ELF3可能代表了高等植物的昼夜节律振荡器的光感觉输入通路和发育反应之间的联系。在模式植物中建立光形态建成和开花的遗传和分子基础的框架将使更好地在商业上重要的植物中设计所需的修饰成为可能。

Meeks-Wagner9808208The Early Flowering 3(ELF3) gene has been cloned from Arabidopsis thaliana and has been found to lack any similarity to genes in the available databases. Results to date suggest that ELF3 functions as a novel key regulator of the circadian oscillator, as well as a regulator of inflorescence and floral meristem identity genes. The hypothesis that the ELF3 gene product regulates photoperiodism by functioning as a component of a photosensory pathway that controls the activity of circadian clocks will be tested. The role of ELF3 in regulating the genetic pathways that control floral initiation and flower meristem development will also be investigated. The specific aims are: 1) To characterize the spatial and temporal regulation of ELF3 transcription and translation 2) To create and characterize -developmentally and for circadian responses- various transgenic lines that overexpress or ectopically express ELF3 by using the endogenous ELF3 regulatory sequences, and constitutive, tissue specific, inducible promoter systems 3) To define the genetic pathways related to ELF3 gene function that regulate floral initiation and meristem identity in Arabidopsis 4) To identify gene products that interact with ELF3 to facilitate proper circadian response and flowering and to identify genes regulated by ELF3 function which may be downstream genes or genes that are autoregulated components of the circadian clock.The long-term goal of this research is to understand the molecular mechanisms that regulate plant developmental responses to changes in daylength. Responses such as floral initiation are likely to be controlled by photosensory pathways that also impinge upon the function of the circadian clocks of plants. A molecular genetic approach to understanding the photoperiodic control of flowering in Arabidopsis will be taken, focused upon the ELF3 gene, isolated and characterized in this laboratory. Previous results suggest the possibility that ELF3 represents a link between photosensory input pathways to the circadian oscillator and developmental responses in higher plants. The development of a framework for the genetic and molecular basis of photomorphogensis and floral initiation in the model plant will make it possible to better engineer desirable modifications in commerically important plants.