Molecular Genetic Analysis of Shoot Apical Meristem Development in Arabidopsis thaliana

[00:8085 . 53]巴顿地球上的主要生产者，植物和藻类，捕捉阳光并利用它来制造地球上所有其他生物赖以生存的生物量。植物的大部分生长发生在树枝的顶端，那里是未分化的分裂细胞区域，称为分生组织。芽的分生组织产生新叶、茎和花。凯瑟琳·巴顿博士的实验室研究茎分生组织的工作原理。她的实验室以小杂草拟南芥为模型系统，研究指导分生组织功能的基因和蛋白质。本课题主要研究拟南芥的SHOOT MERISTEMLESS （STM）基因的调控。当STM蛋白缺乏时，植物不能产生分生组织，相反，当STM蛋白过量供应时，植物产生大量覆盖叶片的分生组织，导致植物高度变形。从这些观察结果可以得出，STM基因必须被小心地调控。为了防止STM在种子叶中的表达，需要BOBBER基因；在bobber突变体中，种子叶不恰当地表达STM。Bobber突变体在胚胎发生过程中也会抑制生长。为了了解BOBBER调控STM的机制，我们将对BOBBER基因进行分子克隆和鉴定。将仔细分析Bobber突变胚，以确定它们在子叶和茎尖分生组织发育方面的缺陷程度。还将确定BOBBER在抑制叶片STM中的作用，并定义BOBBER作用的顺式作用序列。这些实验，以及其他实验，正在引导我们提高对基本植物生物学的理解，这些信息最终将改善我们管理作物、林地和其他自然资源的方式。

0080853BartonThe Earth's primary producers, plants and algae, capture sunlight and use it to make the biomass that all other organisms on the planet use to survive. Much of plant growth occurs at the tips of branches, where regions of undifferentiated, dividing cells, called meristems, are located. The shoot meristems produce new leaves, stems and flowers. Dr. Kathryn Barton's lab studies how shoot meristems work. Using the small weed Arabidopsis as a model system, her lab studies the genes and proteins that direct meristem function. The work in this proposal focuses on regulation of the SHOOT MERISTEMLESS (STM) gene product of Arabidopsis. When the STM protein is lacking, the plant is not able to make a meristem, and conversely, when the STM protein is supplied in excess, the plant produces a mass of meristems that covers the leaves and results in a highly deformed plant. From these observations it follows that the STM gene must be carefully regulated. The BOBBER gene is required to prevent the expression of STM in the seed leaves; in bobber mutants, the seed leaves inappropriately express STM. bobber mutants also arrest growth during embryogenesis. To understand the mechanism of STM regulation by BOBBER, the BOBBER gene will be molecularly cloned and characterized. bobber mutant embryos will be carefully analyzed to determine the extent to which they are defective in the development of cotyledons and shoot apical meristem. The role of BOBBER in repressing STM in leaves will also be determined and the cis-acting sequences through which BOBBER acts will be defined. These, and other experiments, are leading to improvements in our understanding of basic plant biology, information that will ultimately improve the way in which we manage our crops, woodlands and other natural resources.