Benzoic Acid Biosynthesis in Plants

植物中苯甲酸的生物合成

• 批准号: 0919987
• 负责人: Natalia Doudareva
• 金额: $ 104.26万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0919987&HistoricalAwards=false
• 关键词: Benzoic; Acid; Biosynthesis; Plants

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-15). Intellectual Merit: Numerous plant compounds, including natural plant growth regulators, defensive compounds, pathogen-induced phytoalexins, pollinator attractants and flavor compounds, contain benzoyl moieties derived from benzoic acid and play crucial roles in plant survival and reproductive success in natural ecosystems. Despite the simple structure of benzoic acid, widespread distribution and importance for the plant life cycle, the biochemical pathways leading to its formation remain largely unknown. The goal of the proposed research is to discover unknown biochemical pathways leading to benzoic acid biosynthesis, biochemically characterize the enzymes involved and determine their localization in the cell. A unique integrative approach including genetics, metabolomics, functional genomics and metabolic flux analysis will be employed to dissect the pathways to benzoic acid biosynthesis in plants. Petunia flowers, emitting large amounts of benzenoid compounds, represent an ideal model system for the elucidation of the metabolic pathways leading to benzoic acid formation and will be used in this research. The natural emission of methylbenzoate as well as a variety of other volatile benzoic acid derivatives from petunia flowers enables a rapid, quantitative analysis of flux through the benzenoid network. Candidate genes involved in benzoic acid biosynthesis will be silenced using RNAi methodology. The use of a petal-specific promoter will ensure that benzoic acid synthesis will be affected in petals only, thus minimizing unwanted effects on plant viability, growth, and reproduction. Transgenics with altered benzoic acid metabolism will be subjected to metabolic profiling, isotopic labeling experiments and computer-assisted pathway modeling to assess the carbon flow within benzoic acid network and detect flux redistribution during metabolic perturbation. Enzymes encoded by genes whose silencing leads to changes in benzoic acid metabolism will be biochemically characterized. Subcellular localization of these enzymes will be determined experimentally to evaluate the potential role of compartmentalization in regulating flux to benzoic acid. This research will result in the fundamental discovery of genes and enzymes involved in benzoic acid biosynthesis and fill important gaps in our knowledge of benzoic acid metabolism. Obtained results will provide a comprehensive understanding of structural and regulatory properties of the benzoic acid network and lay a foundation for future rational metabolic engineering of plants to improve flavor and aroma quality, boost plant defenses against environmental adversities, increase pollinator attraction and heighten amounts of biologically active compounds. Broader Impacts: This project has a strong multidisciplinary training component for the next generation of plant biochemists. The undergraduate and graduate students, as well as post-doctoral scientists (including women and minorities) will gain experience in plant enzymology, molecular biology, in vivo isotopic labeling, genetics, and integrative modeling. In addition to training students in the laboratory, the PI will organize a Graduate Research Seminar on biochemistry and metabolic engineering of plant secondary metabolism that will bring graduate students and postdocs from the US together with others from around the world and will precede the Gordon Research Conference on Plant Metabolic Engineering in 2011. This seminar will provide young scientists with a deeper understanding of plant metabolism and more actively involve them in science and education, as well as help them build professional relationships with future colleagues from abroad, particularly helpful since plant biochemistry is quite strong in certain foreign countries (e.g., Germany, Japan). Results and approaches used in this research will also be integrated into undergraduate and graduate education at Purdue University by developing course modules focused on plant specialized metabolism. The PI will provide mentorship to trainees for success in their future scientific endeavors.

该奖项是根据2009年《美国回收与再投资法》（公法111-15）资助的。智力优点：许多植物化合物，包括天然植物生长调节剂，防御性化合物，病原体诱导的植物甲状腺素，授粉媒介吸引剂和风味化合物，含有苯并酸衍生的苯甲酰基部分，在植物生存中起着至关重要的作用，在天然生态系统中起着至关重要的作用。尽管苯甲酸的简单结构，对植物生命周期的广泛分布和重要性的简单结构，但导致其形成的生化途径仍在很大程度上未知。拟议的研究的目的是发现导致苯甲酸生物合成的未知生化途径，生化在生化上表征所涉及的酶并确定其在细胞中的定位。将采用一种独特的综合方法，包括遗传学，代谢组学，功能基因组学和代谢通量分析，以剖析植物中苯甲酸生物合成的途径。矮牵牛的花朵发出了大量的苯苯二酚化合物，代表了阐明导致苯甲酸形成的代谢途径的理想模型系统，并将用于这项研究。甲基苯甲酸酯的自然发射以及来自矮牵牛花的各种挥发性苯甲酸衍生物可以通过苯苯二甲酸网络对通量进行快速定量的分析。使用RNAi方法将参与苯甲酸生物合成的候选基因将被沉默。花瓣特异性启动子的使用将确保仅在花瓣中影响苯甲酸的合成，从而最大程度地减少对植物生存能力，生长和繁殖的不良影响。苯甲酸代谢改变的转基因将经过代谢分析，同位素标记实验和计算机辅助途径建模，以评估苯甲酸网络中的碳流量并检测代谢扰动期间的通量再分配。由基因编码的酶会导致苯甲酸代谢变化的基因的变化。这些酶的亚细胞定位将在实验中确定，以评估分隔在调节通量向苯甲酸中的潜在作用。这项研究将导致与苯甲酸生物合成有关的基因和酶的基本发现，并填补我们对苯甲酸代谢的了解。获得的结果将为苯甲酸网络的结构和调节性质提供全面的了解，并为未来的植物代谢工程奠定了基础，以提高风味和香气质量，促进植物防御环境逆境，增加授粉媒介吸引力并增加生物活性化合物的量。更广泛的影响：该项目为下一代植物生物化学家提供了强大的多学科培训组成部分。本科生和研究生以及博士后科学家（包括妇女和少数民族）将获得植物酶学，分子生物学，体内同位素标记，遗传学和综合建模的经验。除了培训实验室的培训学生外，PI还将组织一项研究生研究研讨会关于植物次要代谢的植物次要代谢的生物化学和代谢工程学研讨会，该研讨会将使美国的研究生和研究生与世界各地的其他人一起，并将在2011年的戈尔登植物代谢工程会议上提供更多的植物学教育，并将其与植物学的教育相关联。当他们帮助他们与来自国外的未来同事建立专业关系时，特别是有帮助的，因为在某些国外（例如，德国，日本）的植物生物化学非常牢固。这项研究中使用的结果和方法还将通过开发针对植物专业代谢的课程模块来纳入普渡大学的本科和研究生教育。 PI将为受训者提供指导，以在未来的科学努力中取得成功。