Arabidopsis 2010: Functional Genomics of Arabidopsis Starch Granule Metabolism

拟南芥淀粉代谢基因网络的分子和生理功能将被确定。尽管构成淀粉的葡萄糖聚合物的化学结构简单，但其复杂的分子结构对淀粉的功能至关重要。拟南芥基因组序列允许鉴定所有参与淀粉生物合成或动员的基因，并确定每个基因产物单独和在代谢网络中的功能。新陈代谢的这一方面是所有植物生命的一个显著特征，光合作用的代谢收益被储存起来，并在以后没有光作为能量来源时使用。因此，了解淀粉的组装和拆卸是一个全面的化学系统，是对拟南芥基因组序列信息如何转化为植物生命形式的完整功能描述所必需的。在这个项目中，“确定功能”意味着每种蛋白质在淀粉聚合物的组装或拆卸中的作用将在特定分子相互作用的水平上被理解。该项目重点关注葡萄糖基单位供体产生后可能参与淀粉代谢的28个基因。该基因集包括淀粉合成酶、分支酶、去分支酶、a-淀粉酶、b-淀粉酶、歧化酶和淀粉磷酸化酶。在每一种情况下，基因组序列都预示着多种同种异构体。该项目的两个组织假设是，大多数同工异构体在创建或拆除淀粉的分子结构中具有特定的，不重叠的作用，并且网络的许多组成部分通过直接的功能相互作用而不是通过一系列独立的酶步骤起作用。研究结果将通过科学出版物、定期网络发帖（www.starchmetnet.com）和科学会议进行分享。将开发并提供给科学界的资源包括突变系、同工异构体特异性抗体和纯化重组酶。该项目将对mRNA分析、生物化学和生物信息学等领域各级科学家的培训产生更广泛的影响。该项目将努力通过与传统上为这些学生提供服务的大学建立伙伴关系，让代表性不足的群体成员在本科一级参与这项活动。淀粉提供了人类饮食中的大部分热量，也是能源生产和工业原料的可再生资源。全面了解这种储能系统将提供更大的能力来开发可再生植物资源，以满足我们不断变化的社会和环境不断增长的需求。

The molecular and physiological functions of the Arabidopsis starch metabolism gene network will be determined. The glucose polymers that make up starch, despite their simple chemical structures, display a complex molecular architecture that is essential for starch function. The Arabidopsis genome sequence allows identification of all the genes involved in starch biosynthesis or mobilization, and determination of the function of each gene product individually and within the metabolic network. This aspect of metabolism is a distinguishing feature of all plant life, by which the metabolic gains of photosynthesis are stored and used later when light is not available as the energy source. Understanding starch assembly and disassembly as a comprehensive chemical system, therefore, is required for a complete functional description of how the sequence information in the Arabidopsis genome is translated into the plant life form. In this project, "determination of function" implies that the role of each protein in the assembly or disassembly of starch polymers will be understood at the level of specific molecular interactions. The project focuses on 28 genes that are likely to be involved in starch metabolism after the production of the glucosyl unit donor. The gene set includes starch synthases, branching enzymes, debranching enzymes, a-amylases, b-amylases, disproportionating enzymes, and starch phosphorylases. In each instance the genome sequence predicts multiple isoforms. The two organizing hypotheses of the project are that most isoforms have specific, non-overlapping roles in creating or dismantling the molecular architecture of starch, and that many components of the network act via direct functional interactions rather than in a series of independent enzymatic steps. Results will be shared through scientific publication, regular web postings (www.starchmetnet.com), and via scientific conferences. Resources that will be developed and made available to the scientific community include mutant lines, isoform-specific antibodies, and purified recombinant enzymes. The project will have broader impacts in the training of scientists at all levels in areas such as mRNA profiling, biochemistry, and bioinformatics. The project will strive to involve members of under-represented groups in this activity at the undergraduate level, through established partnerships with universities that traditionally serve such students. Starch provides the majority of calories in the human diet, and is also a renewable resource for energy production and industrial raw materials. Comprehensive understanding of this energy storage system will provide a greater ability to exploit renewable plant resources to meet the continually increasing demands of our changing society and environment.