Cold Signaling and the Regulation of CBF Genes in Arabidopsis

低温是影响植物生长发育和生存的最常见的环境因子之一。了解植物对低温的响应不仅有助于阐明生物低温感知的基本机制，而且对农业具有重要意义，因为低温胁迫极大地限制了作物的生产。本研究的长期目标是了解植物冷感知和信号转导的机制。这个项目的重点是低温如何改变对植物耐寒性重要的基因的表达。先前的研究表明，植物基因的冷诱导是由转录级联控制的，其中寒冷首先触发编码CBF转录因子家族的基因的转录，进而激活大量下游冷响应基因的表达。目前人们对CBF基因是如何被寒冷诱导的了解甚少。初步工作已经确定了几种拟南芥突变体在CBF基因的冷诱导中受损。该项目将描述和克隆由这些突变体定义的遗传位点之一。利用全基因组芯片对该突变体进行基因表达谱分析。该项目将导致低温反应的关键调控基因的分离。这项工作将极大地促进我们对低温线索的生物感知的理解，并提高我们制定合理策略的能力，以设计抗寒和抗冻作物。为了扩大研究的影响，该项目将参与一个暑期实习计划，培训高中科学教师，并将参与其他几个外展计划，为学生提供植物突变体和发光成像专业知识，以进行分子遗传实验室练习；它将积极招募本科生，让他们参与发现过程。

Low temperature is one of the most common environmental factors influencing the growth, development and survival of plants. Understanding plant responses to low temperature not only helps illuminate fundamental mechanisms of biological low temperature sensing, but also is of critical importance for agriculture because chilling and freezing stresses greatly limit crop production. The long-term goal of this research is to understand the mechanisms of cold sensing and signal transduction in plants. This project focuses on how cold temperatures switch on the expression of genes that are important for plant cold tolerance. Previous work has shown that cold-induction of plant genes is controlled by a transcriptional cascade where cold first triggers the transcription of genes encoding the CBF family of transcriptional factors that in turn activate the expression of a large number of downstream cold-responsive genes. How the CBF genes are induced by cold is currently poorly understood. Preliminary work has identified several Arabidopsis mutants that are impaired in the cold induction of CBF genes. The project will characterize and clone one of the genetic loci defined by these mutants. Gene expression profiling using whole genome microarrays will be carried out on this mutant. The project will lead to the isolation of a critical regulatory gene for low temperature responses. The work will significantly advance our understanding of biological sensing of low temperature cues and enhance our ability to develop rational strategies for engineering chilling and freezing tolerant crops. To broaden the impacts of the research, the project will participate in a summer intern program to train high school science teachers, and will be involved in several other outreach programs by providing plant mutants and luminescence imaging expertise to molecular genetic lab exercises for students; and it will actively recruit and involve undergraduate students in the discovery process.