Molecular Genetic Analysis of Spatial-Specific Phytochrome Responses in Arabidopsis Thaliana

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。植物的不同器官，组织和细胞可以对环境线索表现出不同的反应（例如，在去黄化期间，光刺激子叶生长，而光抑制下胚轴生长）。器官和组织特定池的光吸收光敏色素启动不同的信号级联，影响离散的生理反应的假设正在测试这些调查。在这个项目中，一种新的靶向分子方法被用来代谢光敏色素发色团，从而特异性地消耗植物不同细胞和组织中的光敏色素。这种方法是理解细胞和组织中光敏色素功能的先决条件（即，空间特异性）水平，并允许控制植物中光敏色素缺乏的严重性和定位，这是使用经典突变体分离或RNAi技术随后进行表型分析无法实现的。为了鉴定光敏色素信号转导的新的空间特异性方面和光形态建成的不同方面的分子基础，将追求以下目标：（1）与拟南芥中去黄化的不同方面相关的新的空间特异性光敏色素响应的表征;（2）鉴定负责靶向光敏色素中空间特异性光敏色素响应的分子机制-发色团缺陷系;和（3）在靶向光敏色素-发色团缺陷系中开花的空间特异性光调节的表征。分子遗传学和基因组学方法正在被用来实现这些目标。从这些研究的结果，预计将有助于显着我们的理解复杂的光敏色素依赖的信号通路，在高等植物中通过识别特定的细胞机制和候选基因参与调控的独特方面的光介导的植物生长和发育。更广泛的影响：这项研究的重点是提高胆蛋白调节光形态发生的分子机制的基本理解。从这些研究的结果，预计将产生新的见解细胞和组织特异性池的光敏色素，细胞间的工作，以协调控制植物生长和发育的独特方面，响应于光的分子基础，并可能导致改善农业实践，最大限度地提高光依赖性生长的农学上重要的植物。除了研究生和博士后学者的培训，这些调查的更广泛的影响包括研究经验，旨在发展批判性思维和分析能力的本科科学专业和学生从代表性不足的群体，包括学生在查尔斯德鲁科学丰富计划在密歇根州立大学和参与者在密歇根州立大学植物基因组学夏季研究经验的本科生计划。还为博士后助理制定了指导和专业发展计划，以促进对参与的博士后科学家的全面培训。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Distinct organs, tissues and cells of plants can display different responses to environmental cues (e.g., during de-etiolation cotyledon growth is stimulated by light, whereas hypocotyl growth is inhibited by light). The hypothesis that organ- and tissue-specific pools of light-absorbing phytochromes initiate distinct signaling cascades that effect discrete, physiological responses is being tested in these investigations. In this project, a novel targeted molecular approach is being used to inactivate metabolically the phytochrome chromophore and thereby specifically deplete phytochromes in distinct cells and tissues of plants. Such an approach is a prerequisite for understanding phytochrome functions at the cellular and tissue (i.e., spatial specific) level and allows control over the severity and localization of phytochrome deficiency in plants that is not achievable using classical mutant isolation or RNAi technology followed by phenotypic analyses. To identify novel spatial-specific aspects of phytochrome signaling and the molecular bases of distinct aspects of photomorphogenesis, the following objectives will be pursued: (1) the characterization of novel spatial-specific phytochrome responses associated with distinct aspects of de-etiolation in Arabidopsis thaliana; (2) the identification of molecular mechanisms responsible for spatial-specific phytochrome responses in targeted phytochrome-chromophore deficient lines; and (3) the characterization of spatial-specific photoregulation of flowering in targeted phytochrome-chromophore deficient lines. Molecular genetic and genomic approaches are being utilized to accomplish these objectives. The results from these studies are expected to contribute significantly to our understanding of the complex phytochrome-dependent signaling pathways that operate in higher plants through the identification of specific cellular mechanisms and candidate genes involved in the regulation of distinctive aspects of light-mediated growth and development in plants. Broader Impacts: This research focuses on improving fundamental understanding of molecular mechanisms of biliprotein-regulated photomorphogenesis. Results from these studies are expected to yield novel insight into the molecular bases of cell- and tissue-specific pools of phytochromes that work intercellularly to coordinately control distinctive aspects of plant growth and development in response to light and may lead to improved agricultural practices for maximizing light-dependent growth of agronomically important plants. In addition to the training of graduate students and postdoctoral scholars, broader impacts of these investigations include research experiences designed to develop the capacity to think critically and analytically of undergraduate science majors and students from underrepresented groups, including students in the Charles Drew Science Enrichment Program at Michigan State University and participants in the MSU Plant Genomics Summer Research Experience for Undergraduates Program. A mentoring and professional development plan for postdoctoral associates also has been developed to promote the comprehensive training of participating postdoctoral scientists.