Defining the Plant Cell Wall Xyloglucan Biosynthetic Complex Localized in Golgi

智力上的优点。木葡聚糖是一种半纤维素，是许多植物初级细胞壁的主要组成部分，具有重要的结构和生理功能。除纤维素外，木葡聚糖是最具特性的细胞壁多糖，在鉴定和鉴定参与其合成的酶方面已取得了相当大的进展。最近，6种高尔基体定位的转移酶被证明与木葡聚糖的形成有关。然而，这些酶在高尔基体膜中的功能组织和调控目前尚不清楚。该项目的初步研究发现，三种酶之间有明显的等级关系，并证明了所有六种酶都以成对的方式相互作用。该项目的科学目标是确定这种多酶复合体在模式物种拟南芥植物细胞合成木聚糖过程中的结构组织和功能调节。研究结果将有助于为定位于该植物和其他植物高尔基复合体中的多糖生物合成机械的功能组织建立机制基础。该项目的成果将促进对植物进行工程改造，以生产具有改良性质的半纤维素，这将加强开发和保护免受环境压力的影响，并将增加工业对植物多糖的使用兴趣。这项研究将与密歇根州立大学和加州大学河滨分校合作完成。合作将为本科生和研究生创造广阔的机会和出色的环境，通过生物化学、细胞和分子生物学的综合项目进行培训。本科生将通过爱荷华州立大学暑期本科生研究项目和女性科学与工程项目招收。每年将为一名实习生提供为期六周的暑期研究体验。该项目还将包括与爱荷华州立大学分校合作，通过参加年度研讨会和创建互联网网页，向当地生物质种植者、土地管理人员和普通公众传达有关植物生物量组成、形成和修改的科学信息。

Intellectual merit. Xyloglucan, a hemicellulose, is a major component of the primary cell wall of many plants and provides important structural and physiological functions. With the exception of cellulose, xyloglucan is the best characterized cell wall polysaccharide, and considerable progress has been made to identify and characterize the enzymes involved in its synthesis. Recently, six Golgi-localized transferase enzymes were shown to be involved in xyloglucan formation. However, the functional organization and regulation of these enzymes in the Golgi membrane is currently unknown. Preliminary research for this project found distinct hierarchal roles among three of the enzymes and demonstrated that all six interact in pair-wise fashion with each other. The scientific goal of this project is to define the structural organization and functional regulation of this multi-enzyme complex during the synthesis of xyloglucan in the plant cell in the model species, Arabidopsis thaliana. Research results will help to establish the mechanistic basis for the functional organization of the polysaccharide biosynthetic machinery localized in the Golgi complex of this and other plant species.Broader Impacts. The outcome of the project will facilitate the engineering of plants to produce hemicelluloses with modified properties that will enhance development and protection against environmental stress, and will increase industrial interest in the use of plant polysaccharides. This research will be accomplished in collaboration with Michigan State University and University of California at Riverside. The collaboration will create broad opportunities and an outstanding environment for undergraduate and graduate students to be trained through a combined program of biochemistry, cell, and molecular biology. Undergraduate students will be recruited through the Iowa State University Summer Undergraduate Research Programs and the Program for Women in Science and Engineering. A six-week summer research experience will be provided for one intern each year. The project will also include a collaboration with the Iowa State University Extension to convey scientific information on plant biomass composition, formation, and modification to local biomass growers, land managers and the general public through participation in annual workshops and the creation of an internet webpage.