Biosynthesis of Xyloglucan by Plant Golgi Membranes

木葡聚糖是植物细胞壁基质多糖， 由高尔基体膜中的酶合成。 木葡聚糖在细胞壁结构和细胞生长中起着重要作用。 功能 此外，它还可能具有调节功能， 控制植物生长和发育的过程。 这是一个 复杂的多糖，但与某些多糖相比， 简单. 该提案描述了一项研究计划， 为了阐明木葡聚糖合成酶的活性和 他们制造的产品。 该项目的总体目标是 改进木葡聚糖生物合成系统，用作 植物细胞壁多糖生物合成和 植物高尔基体的结构和功能组织 设备. 这两个研究课题密切相关， 这项研究的完成将大大提高我们的 理解两者。 从悬浮液中分离的高尔基体膜- 培养的枫树pseudoplatanus（西卡莫尔枫树）细胞正在被 亚分级和这些部分纯化的膜级分 被用作木葡聚糖酶的来源。 组合 糖基组成分析，甲基化连锁分析， 和放射性气体比例计数被用来确定 掺入的放射性标记残基和连接的鉴别 他们之间 与木葡聚糖有关的糖基转移酶 合成被纯化， 植物高尔基体的定位和区室作图是可能的。 成功完成这项研究将导致更大的 了解植物细胞壁合成的过程 作为工厂设备的结构和功能。 植物生物学中有许多基本问题没有得到解答。 细胞壁的生物发生对植物生长有什么影响， 发展就是这样一个问题。 这项研究提供了一个 在这方面取得进展的机会。 木葡聚糖是一种 植物细胞壁结构和 功能上。 它们允许细胞壁保持一定程度的 并与生长素刺激的伸长有关 在成长过程中。 本研究是一项深入研究， 这些重要的细胞壁糖的生物合成，并提供了一个 更好地了解高尔基体， 负责其合成的酶。

Xyloglucans are plant cell wall matrix polysaccharides that are synthesized by enzymes in the membranes of the Golgi apparatus. Xyloglucan plays a central role in both cell wall structure and function. In addition, it may have a regulatory function in the process of controlling plant growth and development. It is a complex polysaccharide, yet compared to some it is relatively simple. This proposal describes a program of research designed to clarify the activities of xyloglucan synthase enzymes and the products they make. The overall objective of this project is to refine the xyloglucan biosynthesis system for use as a model for the study of both plant cell wall polysaccharide biosynthesis and the structure and functional organization of the plant Golgi apparatus. These two research topics are closely related and completion of this research will significantly increase our understanding of both. Golgi membranes isolated from suspension- cultured Acer pseudoplatanus (sycamore maple) cells are being subfractionated and these partially purified membrane fractions are being used as a source of xyloglucan synthases. Combinations of glycosyl composition analysis, methylation linkage analysis, and radiogas proportional counting are being used to determine identities of incorporated radiolabeled residues and the linkages between them. The glycosyl transferases involved with xyloglucan synthesis is being purified so that eventual subcellular localization and compartment mapping of plant Golgi are possible. Successful completion of this study will result in a greater understanding of the process of plant cell wall synthesis as well as the structure and function of the plant apparatus. There are many unanswered fundamental questions in plant biology. What influence cell wall biogenesis has on plant growth and development is one such question. This research offers an opportunity for progress in this area. Xyloglucans are an important component of plant cell walls both structurally and functionally. They allow the cell wall to maintain a degree of flexibility and are implicated in auxin-stimulated elongation during growth. This research is an in-depth study of the biosynthesis of these important cell wall sugars and provides a better understanding of the Golgi apparatus which produces the enzymes responsible for their synthesis.