Comparative Genomics Approach to Pathway Discovery and Engineering in Tomato Trichomes

本行动资助NSF国家植物基因组计划2018年度生物学博士后研究奖学金。该奖学金支持奖学金获得者在主办实验室的研究和培训计划，该奖学金获得者还提出了扩大生物学参与的计划。Craig Schenck博士的研究和培训计划的题目是“番茄毛状体路径发现和工程的比较组学方法”该奖学金的主办机构是密歇根州立大学赞助科学家是Robert Last博士。代谢物是植物形态和功能的驱动因子，其产生具有时空性。这些代谢物在一个复杂的酶反应网络中由有机积木组装而成，使植物能够在不同的环境中茁壮成长。许多专门的代谢物参与生态相互作用，但也为人类提供多种代谢物的营养和药用重要性。植物特化代谢的多样性和分类限制为发现新的生物化学反应和研究宏观和微观的进化提供了条件。对具有生物活性的植物代谢产物的基本认识将对改善作物的营养和生产性能产生广泛的影响。具体来说，在重要的农艺物种中增加具有生物活性的植物代谢物提供了一种增强作物防御和生产力的手段。该项目将提供对酶和代谢途径如何进化的基本理解，其原理可以应用于农业，并扩展到理解其他生物系统的进化。培训目标包括功能基因组学、分析化学和生物信息学。更广泛的影响活动包括指导和培训研究生和本科生，组织外展活动以提高公众对植物科学的认识。植物产生无数的谱系特异性代谢物（如生物碱、萜烯等），这些代谢物是由氨基酸等必需的初级代谢物合成的。许多专门的代谢物参与生态相互作用，但也为人类提供多种代谢物的营养和药用重要性。特化代谢的进化往往比受进化限制的初级代谢发生得更快。这种植物特化代谢的最新进化已经在绿色植物谱系中发现了数十万种结构多样的代谢物。植物特化代谢的多样性和分类限制为发现新的生物化学反应提供了条件，并在宏观、代谢途径和微观、酶水平上研究进化。糖酯（酰基糖）是一种特殊的代谢物，仅存在于茄科的许多物种中，它由糖核组成，糖核上装饰着不同的酰基链，具有植物防御和商业特性。连接在酰基糖上的酰基链在数量、长度和分支模式上各不相同，这导致了茄科植物中酰基糖类型和丰度的自然变化。支链氨基酸是C4-C5酰基链的直接前体，但合成更长的酰基链需要延伸。然而，负责链延伸的生化机制仍然未知。该项目将利用包含茄科的丰富数据来确定导致酰基糖多样性的生化机制和进化过程。本项目旨在利用比较基因组学、转录组学、代谢组学、生物化学和传统遗传学等手段，对番茄及其近缘野生近缘植物的酰基链延伸途径进行鉴定和生化表征，通过对鉴定酶的体内功能进行体外生化验证，并对本烟中茄类植物的酰基链延伸途径进行工程设计，以重建该途径，促进生物活性酰基糖的产生。通过该项目获得的所有数据将提交到公开的网站和存储库，手稿将在开放获取期刊上发表。关键词：生物化学，特殊代谢，防御化合物，酰基糖，链延伸该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2018. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Dr. Craig Schenck is "Comparative Omics Approach to Pathway Discovery and Engineering in Tomato Trichomes" The host institution for the fellowship is Michigan State University and the sponsoring scientist is Dr. Robert Last.Metabolites produced in spatial and temporal manner, are the drivers to plant form and function. These metabolites are assembled from organic building blocks in a complex web of enzymatic reactions and allow plants to thrive in diverse environments. Many specialized metabolites are involved in ecological interactions, but also provide humans with diverse metabolites of nutritional and medicinal importance. The diversity and taxonomic restriction of plant specialized metabolism allows for discovery of novel biochemical reactions, and investigation of evolution on a macro and micro level. Fundamental understanding of the production of biologically active plant specialized metabolites will have broad impacts on improving nutrition and performance of crops. Specifically, increasing biologically active plant metabolites in agronomically important species provides a means to enhance crop defenses and productivity. This project will provide a fundamental understanding of how enzymes and metabolic pathways evolve, the principles of which can be applied to agriculture and extended to understand evolution in other biological systems. Training objectives include functional genomics, analytical chemistry, and bioinformatics. Broader impact activities include mentoring and training graduate and undergraduate students and organizing outreach events to raise public awareness of the plant sciences. Plants produce a myriad of lineage-specific specialized metabolites (e.g. alkaloids, terpenes, etc.), which are synthesized from essential primary metabolites like amino acids. Many specialized metabolites are involved in ecological interactions, but also provide humans with diverse metabolites of nutritional and medicinal importance. Evolution of specialized metabolism tends to occur more quickly than evolutionarily constrained primary metabolism. This recent evolution in plant specialized metabolism has given rise to hundreds of thousands of structurally diverse metabolites found in the green plant lineage. The diversity and taxonomic restriction of plant specialized metabolism allows for discovery of novel biochemical reactions, and investigation of evolution on a macro, metabolic pathway, and micro, enzyme, level. Sugar esters (acylsugars) are a group of specialized metabolites restricted to many species within the nightshade family (Solanaceae) that consist of a sugar core decorated with diverse acyl chains and have plant defense and commercial properties. The acyl chains attached to acylsugars vary in number, length, and branching pattern, which gives rise to natural variation in acylsugar types and abundance within Solanaceae. Branched-chain amino acids are the direct precursors of C4-C5 acyl chains, but synthesis of longer acyl chains requires elongation. However, the biochemical mechanisms responsible for chain elongation remain unknown. This project will leverage the wealth of data encompassing the Solanaceae to identify biochemical mechanisms and evolutionary processes leading to the diversity of acylsugars. Using comparative genomics, transcriptomics, metabolomics, biochemistry and traditional genetics, this project aims to identify and biochemically characterize the acyl chain elongation pathway in tomato and closely-related wild relatives, validate in vitro biochemistry by testing the in vivo function of the identified enzymes, and engineer the Solanum acyl chain elongation pathway in Nicotiana benthamiana to reconstitute the pathway and enhance production of biologically active acylsugars. All data obtained through this project will be submitted to publicly available websites and repositories and manuscripts will be published in open access journals.Keywords: biochemistry, specialized metabolism, defense compounds, acylsugar, chain elongationThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.