Molecular and Biochemical Determinants of Floral Scent Production in Antirrhinum majus

金鱼草花香产生的分子和生化决定因素

• 批准号: 9904910
• 负责人: Natalia Doudareva
• 金额: $ 28.5万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9904910&HistoricalAwards=false
• 关键词: Molecular; Biochemical; Determinants; Floral; Scent

Volatile compounds play an important role in plants as insect attractants,repellents and signal molecules. Floral scent is a key modulating factorin plant-insect interactions and plays a central role in successful pollination, and thus in fruit development of many crop species. Despitethe economic importance of floral scent for plant reproduction, little isknown about the molecular mechanisms involved in the production of floral volatiles. The objectives of this proposal are to use molecular, genetic,and biochemical approaches to understand how production of volatiles couldbe manipulated in plants using floral scent as a model system. Althoughproduction of scent volatile compounds appears to be very widespread in theplant kingdom, the information about their biosynthesis and regulation islimited and based to date on the analysis of a single model system -Clarkia. Bee-pollinated Antirrhinum majus (snapdragon) will be used as amodel system for this study due to its important advantages over theClarkia system such as a well developed genetic map, transposon genecloning system, available transformation protocol, and rhythmic emission.Floral scent is often a complex mixture of low molecular weight compounds,which are mainly distributed within three groups: fatty acid derivatives,benzenoids and isoprenoids. Esters of such compounds are among the most common in many plant species where they contribute significantly to thetotal floral scent output. However, the biochemical pathways, enzymes andgenes controlling the biosynthesis of volatile esters in plants have received little attention. The focus of the proposed research is on themolecular mechanisms of the synthesis of the volatile ester methylbenzoate,an important insect attractant and a major component of snapdragon floral scent. This research specifically addresses the questions of how plantsregulate the production of volatile esters and how pollination andcircadian rhythm affect scent emission at the molecular level. Theavailability of a cloned S-adenosyl-L-methionine:benzoic acid carboxylmethyltransferase (BAMT), the final enzyme in the biosynthesis ofmethylbenzoate, recently isolated in the PI's lab, provides a uniqueopportunity to make a detailed study of the regulation of floral scentproduction. The mode of expression of BAMT gene will be characterized indifferent tissues during flower development to determine the molecularmechanisms (transcriptional, translational or post-translational) involvedin the regulation of methylbenzoate emission. Special attention will bepaid to comparative analyses of Antirrhinum varieties that emitmethylbenzoate with non-emitting plants. To determine the specific molecular and biochemicalmechanisms that are responsible for the postpollination changes in floral scent production inplants, the levels of BAMT mRNA, BAMT protein, BAMT activity, emission, andthe possible accumulation of methylbenzoate inside the cells will bedetermined at different times after pollination. Overall, this researchwill lead to significant contributions to understanding of the fundamental processes underlying the formation offloral scent. While this proposal is designed primarily to addressfundamental questions about molecular mechanisms controlling production of volatiles in plants, the results obtained may ultimately find applicationin agriculture and horticulture. An understanding of the enzymology andregulation of metabolic pathways (including developmental changes and subcellular compartmentation), obtained in these studies, will provide theknowledge for engineering plants with improved scent quality to increasethe attraction of pollinators to flowers and thereby increase the yield of important agricultural crops.

挥发性化合物在植物中起着重要作用，作为昆虫吸引剂，驱虫剂和信号分子。 花香味是植物 - 植物启用的关键调节，并且在成功的授粉中起着核心作用，因此在许多作物物种的水果发展中起着核心作用。 鄙视花香在植物繁殖中的经济重要性，关于花卉挥发物的产生的分子机制知之甚少。 该提案的目标是使用分子，遗传和生化方法来了解如何使用花香作为模型系统在植物中操纵挥发物的产量。尽管气味挥发性化合物的生产似乎在植物王国中很普遍，但有关其生物合成和调节的信息是有限的，并且基于对单个模型系统-clarkia的分析。 蜜蜂授粉的抗抗毒物（Snapdragon）将用作本研究的Amodel系统，因为它的重要优势比诸如theclarkia系统的重要优势，例如良好的遗传图，转孔基因座系统，可用的转化方案，可用的转化方案和节律性发射。经常出现较低的酸度酸度，这是三分之一的分配：在三分之一的分配中，这是三分之一的组合：这是三分之一的组合：这是三分之一的组合：衍生物，苯和异丙也是如此。 这种化合物的酯在许多植物物种中最常见，在这些植物物种中，它们对thetotal花卉味道的贡献显着贡献。然而，控制植物中挥发性酯的生物合成的生化途径，酶和基因很少受到关注。 拟议的研究的重点是挥发性酯甲基苯甲酸酯的合成的分子机制，甲基苯甲酸酯是一种重要的昆虫吸引力，也是Snapdragon花香的主要成分。 这项研究专门解决了植物如何调节挥发性酯的产生以及授粉和节奏如何影响分子水平上的气味发射的问题。 克隆的S-腺苷-l-甲宁氨酸：苯甲酸羧甲基转移酶（BAMT），最近在PI的LAB中隔离的甲基苯甲酸酯的生物合成的最终酶，提供了一个独特的propportunity，以详细的研究进行了详细的研究。 BAMT基因的表达方式将在花朵发育过程中表征无动于衷的组织，以确定甲基苯甲酸酯发射的调节的分子机制（转录，翻译或翻译后）。特别关注的是，对与非发射植物发射甲基苯甲酸酯的抗逆性品种的比较分析。 为了确定负责推迟植物花香产生的变化变化的特定分子和生化机制，BAMT mRNA，BAMT蛋白，BAMT蛋白，BAMT活性，发射以及甲基苯甲酸酯在授粉后不同时间内的甲基苯甲酸酯的可能积累。 总体而言，这项研究将为理解对绿色气味的形成基础的基本过程做出重大贡献。虽然该提案主要旨在解决有关控制植物挥发物的分子机制的基础问题，但获得的结果最终可能会在农业和园艺中找到应用。 在这些研究中获得的代谢途径的酶学和代谢途径的酶学（包括发育变化和亚细胞隔室）的理解将为工程植物提供知识，具有提高气味质量的工程植物，从而增加了授粉剂对花朵的吸引力，从而增加了重要的农业作物的产量。