Genetic Analysis of Blue Light Perception and Signal Transduction Mechanisms in Plants

本提案的长期目标是确定 细胞和分子水平如何被植物感知蓝光 并转化为生长反应。 该项目将 研究蓝光的生理和遗传基础 反应在高等植物中使用拟南芥作为模型系统。 我们将集中讨论下胚轴的抑制反应 由连续的蓝光引起的伸长。 具体目标是 分离出许多突变株， 蓝光，并使用这些突变体来表征 信号传导途径，也许是蓝光受体 本身 将对突变体植物进行生理分析。 进行，以确定哪些阶段的反应是 受到突变的影响。 各种蓝色和 红光响应共享信号转导事件。 植物 含有两个或多个光反应突变的基因， 构建并用于研究光依赖性 信号转导网络 蓝光反应突变体 使用互补分析进行遗传表征， 确定信号中涉及的最小步数 转导 最后，这些突变将被映射到它们的 利用T-DNA进行染色体定位和基因分离 插入突变体或通过染色体步移，以鉴定 蓝光信号转导所需的蛋白质。 光不仅为植物提供光合作用所需的能量， 而且还调节植物发育的几乎所有阶段， 独立于光合作用。 对于幼苗来说， 建立自己需要协调行动的许多 发展路径。 光，通过几个 光感受器系统，引发了许多发展变化 对于幼苗来说，从生长在 黑暗的土壤，阳光的照耀。 远红（Far Red） 光受体，光敏色素，已经被最深入地研究， 而蓝色和紫外线受体的性质是 几乎无人知晓 这项建议旨在查明和调查 植物感知和响应蓝光的机制 以及植物如何适应不同的光照条件。 的 蓝光响应系统的研究可能导致 重要的新见解，对生理和分子 苗期光形态建成的调控机制 * //

The long-term objectives of this proposal are to determine at the cellular and molecular level how blue light is perceived by plants and transduced into growth responses. This project will investigate the physiological and genetic basis for blue light responses in higher plants using Arabidopsis as a model system. The response we will concentrate on is the inhibition of hypocotyl elongation caused by continuous blue light. Specific goals are to isolate a number of mutant strains that show altered responses to blue light and to use these mutants to characterize portions of the signal transduction pathway, perhaps the blue light receptor itself. Physiological analysis of the mutant plants will be conducted in order to identify what phases of the response are affected by the mutations. Interactions between various blue and red light responses share signal transduction events. Plants containing two or more light-response mutations will be genetically constructed and used in the investigation of the light-dependent signal transduction networks. The blue light-response mutants will be genetically characterized using complementation analysis to determine the minimum number of steps involved in signal transduction. Finally the mutations will be mapped to their chromosome locations followed by gene isolation, using T-DNA insertion mutants or by chromosome walking, in order to identify the proteins required for blue light signal transduction. Light not only supplies plants with the energy for photosynthesis, but also regulates nearly all stages of plant development, independent of photosynthesis. For a seedling to properly establish itself requires the coordinated action of numerous developmental pathways. Light, through the action of several photoreceptor systems, triggers many of the developmental changes essential for seedlings to make the transition from growing in the darkness of the soil to the light of the sun. The red/far red light receptor, phytochrome, has been the most intensively studied, whereas the nature of the blue and ultraviolet receptors is virtually unknown. This proposal seeks to identify and investigate the mechanisms by which plants perceive and respond to blue light and, thus, how plants adapt to different light conditions. The investigation of blue light response systems is likely to lead to important new insights into the physiological and molecular mechanisms controlling photomorphogenesis during seedling establishment.***//