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。了解植物对低温的反应不仅有助于阐明生物低温感应的基本机制，而且由于低温和冰冻胁迫极大地限制了作物的产量，因此对农业具有至关重要的意义。本研究的长期目标是了解植物的冷感和信号转导机制。这个项目的重点是寒冷温度如何影响对植物耐冷性至关重要的基因的表达。以前的工作表明，植物基因的冷诱导是由转录级联反应控制的，其中冷首先触发编码CBF转录因子家族的基因的转录，进而激活大量下游冷反应基因的表达。目前对寒冷是如何诱导CBF基因的知之甚少。初步工作已经确定了几个在CBF基因冷诱导过程中受损的拟南芥突变体。该项目将表征和克隆由这些突变体定义的一个遗传基因座。将使用全基因组微阵列对该突变体进行基因表达谱分析。该项目将导致分离出一种低温反应的关键调控基因。这项工作将极大地促进我们对低温信号的生物传感的理解，并增强我们开发合理的策略来设计低温和耐寒作物的能力。为了扩大研究的影响，该项目将参与一个暑期实习生项目，培训高中科学教师，并将参与其他几个外展项目，为学生提供植物突变和发光成像专业知识，为学生进行分子遗传学实验室练习；该项目将积极招募本科生，并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.