Gene, Enzyme and Physiological Characterization of Maize Shrunken-2 and Brittle-2 Alleles

谷物，包括玉米或玉米，是世界人类和动物人口的主要卡路里来源，最近被用作石油燃料的替代品。不断上涨的汽油和食品价格每天都在提醒人们谷物的重要性。因此，谷物种子产量和提高产量的机制至关重要。该项目将使用遗传、分子和生化方法来进一步表征一种似乎可以将玉米产量提高两到三倍的遗传变异。该变异是一种淀粉生物合成酶，即二磷酸腺苷葡萄糖焦磷酸化酶(AGPase)。AGPase由两个不同的亚基组成。该项目的一个目标是将最近分离的小亚基所含的变异与之前分离的大亚基变异进行遗传结合，以进一步提高玉米产量。将进行生理实验，以确定小亚基变异导致的增产幅度是否受制于植物的生长条件。这就是大亚基的情况。在更基本的水平上，这两个亚基在催化中的相对作用尚不清楚。分子方法将被用来将该酶的特异性从ATP转换为UTP。如果成功，每个亚基的确切作用就可以被阐明。这些研究的更广泛影响是多方面的。首先，这项工作产生的变异已经并将继续对谷物产量产生重大影响。第二，外展工作将继续教育公众有关转基因植物背后的科学及其对社会的好处。高中生和普通人是特别的目标。该项目还包括为佛罗里达大学的学前教育和培训计划中心做出贡献，该计划促进了K-12学校和密歇根大学教职员工之间的联系。将为参加该计划的K-12教师举办讲座。

Cereals, including corn or maize, are the major source of calories for the world human and animal population and, of late, are used as an alternative to petroleum-based fuels. Rising gasoline and food prices are everyday reminders of the importance of cereals. Accordingly, cereal seed yield and mechanisms to increase it are of paramount importance. This project will use genetic, molecular and biochemical approaches to further characterize a genetic variant that appears to enhance corn yield two to three fold. The variant is in a starch biosynthetic enzyme, adenosine diphosphate glucose pyrophosphorylase (AGPase). AGPase is a composed of two different subunits. A goal of the project is to genetically combine the recently-isolated variant harbored by the small subunit with a previously-isolated large subunit variant to further enhance corn yield. Physiological experiments will be performed to determine whether the extent of yield increase caused by the small subunit variant is subject to growth conditions of the plant. This is the case with the large subunit. At a more basic level, the relative roles of the two subunits in catalysis are not clear. Molecular approaches will be used to convert the specificity of the enzyme from ATP to UTP. If successful, the exact roles of each subunit can be elucidated. The broader impacts of these studies are multifaceted. First, the variants arising from this work have had and will continue to have significant impact on cereal yield. Second, Outreach efforts will continue in educating the public about the science behind transgenic plants and their benefit to society. High school students and the lay public are targeted specifically. The project also includes efforts to contribute to the University of Florida's Center for Precollegiate Education and Training Program, which promotes linkage between K-12 schools and members of the UF faculty. Lectures will be presented to K-12 teachers that participate in the program.