Cellulose synthesis and regulation in plants.

植物细胞壁是一个复杂的动态结构，在植物生长发育过程中起着重要作用。如果不是在细胞壁的背景下，就不可能考虑一个植物细胞或组成植物的细胞纲要。因此，为了更好地了解植物的发育和生长，需要了解控制细胞壁组装和完整性的机制。虽然细胞壁由许多不同的糖聚合物组成，但主要的承重聚合物是纤维素。尽管它的丰富和多年的研究，我们对纤维素是如何制造和整合到生长壁的知识仍然非常有限。我的研究计划的主要目的是解决纤维素是如何合成的，以及这个过程是如何调节的。为了确定纤维素生物合成的机制，我们利用了两个模型系统：一种细菌，葡萄糖醋酸杆菌xylinus，和一种植物，拟南芥。细菌系统的优势在于，纤维素合酶的活性可以很容易地在体外测量，这是迄今为止在植物中很难做到的。而拟南芥适合基因分析，这使我们能够从基因上解剖植物中纤维素的生物合成。这两个系统将用于实现三个短期目标：(1)确定纤维素合酶蛋白的结构-功能关系，(2)分析纤维素合酶复合体结构，(3)识别潜在的纤维素合酶调节因子。结合基因分析，我们将使用现代细胞生物学和生化技术来实验达到这些目标。对纤维素生物合成的深入了解将为理解长链聚合物是如何在自然界中产生的提供基础。此外，这些知识可以应用于创建或修改天然聚合物。纤维素的特性，如影响木材品质的微纤维角、聚合度（葡萄糖单位数）、结晶度等，都具有经济意义。

The cell wall of plants is a complex and dynamic structure with many important roles in plant growth and development. It is impossible to consider a plant cell or the compendium of cells that make up a plant, if not in the context of their cell walls. Gaining a better understanding of how plants develop and grow therefore requires a knowledge of the mechanisms that control both cell wall assembly and integrity. Although the cell wall is made up of many different sugar polymers, the primary load-bearing polymer is cellulose. Despite its abundance and a number years of study, our knowledge of how cellulose is made and integrated into the growing wall is still very limited. The principle aims of my research program are to address how cellulose is synthesized and how this process is regulated. To determine the mechanisms of cellulose biosynthesis we are utilizing two model systems: a bacterium, Gluconoacetobacter xylinus, and a plant, Arabidopsis. The bacterial system has the advantage that cellulose synthase activity can be easily measured in vitro, something that has, so far, been difficult in plants. While Arabidopsis is amenable to genetic analysis, which allows us to genetically dissect cellulose biosynthesis in a plant. These two systems will be used to achieve three short-term objectives: (1) determine the structure-function relationships of cellulose synthase proteins, (2) analyze cellulose synthase complex structure and (3) identify potential cellulose synthase regulators. In combination with genetic analysis we will use modern cell biological and biochemical techniques to experimentally reach these goals. A deeper understanding of cellulose biosynthesis will provide the basis for understanding how long chain polymers are made in nature. In addition, this knowledge can be applied to creating or modifying natural polymers. Features of cellulose such as microfibril angle, which affects wood quality, the degree of polymerization (number of glucose units), and it’s crystallinity are all of economic interest.