Cold Acclimation in Arabidopsis thaliana

植物已经进化出适应和生存各种环境胁迫的机制。了解这些机制如何运作是我们了解生物适应知识的基础，并可能为提高重要作物和园艺植物物种的环境胁迫耐受性提供新方法。该奖项的主要兴趣在于了解冷驯化的分子基础，即植物在低非冰冻温度下增加抗冻性的过程。我们的大部分工作是研究小型开花植物拟南芥。研究表明，拟南芥具有冷驯化能力，在冷驯化过程中基因表达发生变化。现在的主要目标是确定cor（冷调节）基因是否在抗冻性或低温存活的其他方面起关键作用。为了解决这些问题，Thomashow博士和他的同事们分离了五个拟南芥基因的cDNA和/或基因组克隆。初步表征表明，这些基因中的某些可能编码冷冻保护多肽。许多被提议的实验都是为了验证这一假设。此外，实验提出，将增加我们的知识，在基因表达的变化的幅度和性质，发生在冷适应。综上所述，这些研究不仅增加了我们对植物如何适应低温的理解，而且还可能导致鉴定出可用于操纵植物的冷冻和/或低温耐受性的基因。＊＊＊

9307348 Thomashow Plants have evolved mechanisms that enable them to acclimate to, and survive, a variety of environmental stresses. Understanding how these mechanisms operate is fundamental to our knowledge of biological adaptation and may suggest novel approaches to improve the environmental stress tolerance of important crop and horticultural plant species. The primary interest of this award is in understanding the molecular basis of cold acclimation, the process whereby plants increase in freezing tolerance in response to low nonfreezing temperatures. Most of our work is with the small flowering plant Arabidopsis. It has been shown that Arabidopsis is capable of cold acclimating and that changes in gene expression occur during the cold acclimation process. A major goal now is to determine whether the cor (cold-regulated) genes have critical roles in freezing tolerance or some other aspect of low temperature survival. To address these issues, Dr. Thomashow and his colleagues have isolated cDNA and/or genomic clones for five Arabidopsis cor genes. The initial characterization suggests that certain of these genes may encode cryoprotective polypeptides. Many of the proposed experiments are directed at testing this hypothesis. In addition, experiments are proposed that will increase our knowledge of the magnitude and nature of the changes in gene expression that occur during cold acclimation. Taken together, these studies should not only add to our understanding of how plants acclimate to low temperature, but may also result in the identification of genes that can be used to manipulate the freezing and/or chilling tolerance of plants. ***