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: 0446040
• 负责人: Harry Klee
• 金额: --
• 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: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0446040&HistoricalAwards=false
• 关键词: Functional; Analysis; Plant; Carotenoid; Dioxygenases

This proposal addresses the functions of a class of enzymes known as carotenoid cleaving dioxygenases (CCDs). These enzymes metabolize carotenoids, creating a vast array of molecules that are economically important in the food industry as colorants and contribute to flavor. The products of these enzymes, generally known as 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 the major scent volatiles in roses. Four CCD enzymes (CCD1, CCD4, CCD7 and CCD8) of unknown function have been the focus of research. Studies to date have shown that 9,10 (9',10') cleavage of diverse carotenoid substrates by CCD1 is a major source of volatiles and flavor constituents in tomato and petunia. CCD1 also plays a major role in regulating accumulation of nutritionally important carotenoids such as beta-carotene in cereal grains. Mutations in CCD7 and CCD8 cause major alterations in plant growth, particularly in the ability of the plant to make branches. Therefore, It has been concluded that CCD7 and CCD8 act together in the synthesis of a novel, and as yet unidentified, apocarotenoid hormone. The continuing work will have three key objectives: 1) An integrated, multitiered strategy aimed at identifying the biologically active compound synthesized by the CCD7/CCD8. 2) Comparative analysis of CCD7 and CCD8 function in divergent plant species. 3) Functional analysis of CCD4 with goals of defining its substrate specificity and its role in leaf development.Broader Impacts: The work has already generated material that will be fundamentally important to human nutrition, taste and aroma. A collaboration aimed at increasing carotenoid content in cereal grains that has the potential to impact the developing world has also been initiated. This research will be used as a platform to educate undergraduate and graduate students, including minority students from Fort Valley State University, an 1890 Land-Grant University.

这一提议涉及一类被称为类胡萝卜素裂解双加氧酶（CCD）的酶的功能。 这些酶代谢类胡萝卜素，产生大量的分子，这些分子在食品工业中作为着色剂具有重要的经济意义，并有助于风味。 这些酶的产物，通常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色素、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。 其中四种功能未知的CCD酶（CCD 1、CCD 4、CCD 7和CCD 8）一直是研究的热点。 迄今为止的研究表明，CCD 1对不同类胡萝卜素底物的9，10（9 '，10'）裂解是番茄和矮牵牛中挥发物和风味成分的主要来源。 CCD 1还在调节谷物中营养重要的类胡萝卜素如β-胡萝卜素的积累中起主要作用。 CCD 7和CCD 8的突变导致植物生长的重大改变，特别是植物产生分支的能力。 因此，可以得出结论，CCD 7和CCD 8在一种新的、尚未鉴定的脱辅基类胡萝卜素激素的合成中共同起作用。 持续的工作将有三个关键目标：1）一个综合的，多层次的战略，旨在确定由CCD 7/CCD 8合成的生物活性化合物。2)不同植物中CCD 7和CCD 8功能的比较分析3)CCD 4的功能分析，目的是确定其底物特异性及其在叶片发育中的作用。更广泛的影响：这项工作已经产生了对人类营养、味觉和香气至关重要的物质。 还发起了一项旨在增加谷物中类胡萝卜素含量的合作，这有可能对发展中世界产生影响。 这项研究将被用作一个平台，教育本科生和研究生，包括少数民族学生从福特谷州立大学，1890年的赠地大学。