Functional Analysis of Plant Carotenoid Dioxygenases

植物类胡萝卜素双加氧酶的功能分析

• 批准号: 0749266
• 负责人: Harry Klee
• 金额: $ 50万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0749266&HistoricalAwards=false
• 关键词: Functional; Analysis; Plant; Carotenoid; Dioxygenases

This project addresses the functions of a class of enzymes known as carotenoid cleaving dioxygenases (CCDs). These enzymes metabolize carotenoids, creating a vast array of economically important molecules. Some of the products of these enzymes, called apocarotenoids, also have biological activity in plants and animals. Important apocarotenoids include retinoids in animals, abscisic acid in plants, the major colorant and flavor compound in saffron, and major scent volatiles in roses. The investigators have focused on four CCD enzymes (CCD1, CCD4, CCD7 and CCD8). Two of the enzymes, CCD1 and CCD4 appear to function in synthesis of flavor and scent volatiles. They also have as yet undefined roles in carotenoid turnover. Loss of either of these two gene products significantly increases the carotenoid content of seeds. The project will address the functions of these two enzymes as it relates to carotenoid content with the potential to enhance the nutritional composition of some foods. Techniques for characterizing the biochemical activity of CCD1 were developed during the prior funding period. These techniques will now be applied to biochemical characterization of CCD4. CCD7 and CCD8 act coordinately to synthesize an as yet unidentified novel plant hormone that regulates the ability of the plant to make branches. A major goal of the investigators, together with collaborators, is to identify the biologically active compound synthesized by the CCD7/CCD8. In addition to isolation of the hormone from plant tissue, the biochemical properties and substrate preferences of CCD7 and CCD8 will be determined. A related goal is to characterize the natural variance within maize populations of CCD7 and CCD8. Broader Impacts: The project is expected to provide fundamental insights into the functions of the CCD enzymes. Understanding the roles of these enzymes in vivo has great potential to improve both flavor and nutrition of foods, especially in the developing world. The project also has the potential to identify an entirely new class of plant hormones that regulate plant architecture. This research is a platform to educate undergraduate and graduate students, including minority students from Fort Valley State University, an 1890 Land-Grant University.

这个项目解决了一类酶的功能，称为类胡萝卜素裂解双加氧酶（CCD）。这些酶代谢类胡萝卜素，产生大量经济上重要的分子。这些酶的一些产物，称为脱辅基类胡萝卜素，在植物和动物中也具有生物活性。重要的脱辅基类胡萝卜素包括动物中的类视黄酸、植物中的脱落酸、玫瑰中的主要着色剂和风味化合物以及玫瑰中的主要香味挥发物。研究人员集中在四种CCD酶（CCD 1，CCD 4，CCD 7和CCD 8）上。其中两种酶，CCD 1和CCD 4似乎在风味和气味挥发物的合成中起作用。它们在类胡萝卜素周转中也有尚未确定的作用。这两种基因产物中任何一种的缺失都会显著增加种子中类胡萝卜素的含量。该项目将解决这两种酶的功能，因为它与类胡萝卜素含量有关，有可能提高某些食物的营养成分。用于表征CCD 1的生化活性的技术是在前一个资助期内开发的。这些技术现在将被应用于CCD 4的生化表征。CCD 7和CCD 8协同作用，合成一种尚未鉴定的新型植物激素，调节植物产生分支的能力。研究人员与合作者的主要目标是鉴定由CCD 7/CCD 8合成的生物活性化合物。除了从植物组织中分离激素外，还将确定CCD 7和CCD 8的生化性质和底物偏好。一个相关的目标是表征玉米群体内的CCD 7和CCD 8的自然变异。更广泛的影响：该项目预计将提供对CCD酶功能的基本见解。了解这些酶在体内的作用对改善食品的风味和营养有很大的潜力，特别是在发展中国家。该项目也有可能确定一种全新的植物激素，调节植物结构。这项研究是一个平台，以教育本科生和研究生，包括少数民族学生从堡谷州立大学，1890年的赠地大学。