Genomic Architecture Underlying Biochemical Diversity and Molecular Convergence within the Carnivorous Plants

这项研究的中心目标是研究近亲食肉植物对猎物的消化是如何进化和调节的。食肉植物从非土壤来源（即昆虫）获取养分的非凡能力，在开花植物中独立出现了大约10次。食肉动物的习性包括吸引、捕获和消化猎物，本项目侧重于后一种特征，同时专门测试常见的植物防御蛋白是否被反复重新利用以获取必需的营养物质。该研究的优势在于跨学科的方法，其中将比较多个物种来解决这个问题。该研究对植物生理学，包括植物激素的营养和功能的研究具有重要的潜力。此外，这一建议的结果也对理解植物防御具有广泛的意义，并可能导致发现用于植物疾病管理和替代技术应用的新蛋白质。该项目将能够培训来自不同背景和代表性不足的研究生和本科生，研究结果将纳入本科和研究生课程。通过已建立的合作，该项目将支持面向K-12学生和成人的公共项目，旨在利用有魅力的食肉植物教授与生物进化相关的概念。该研究将研究共同选择在独立进化的食肉植物中用于猎物消化的常见植物防御蛋白，特别是致病相关（PR）蛋白的功能多样化和调控中的作用程度。利用比较基因组学方法和转录组学方法结合靶向治疗，该项目旨在：(1)确定哪些消化功能基因在亲缘关系较远的Drosera和Pinguicula物种的陷阱中表达，以及这些位点是否与植物防御中使用的PR基因同源；(2)研究猎物、伤口信号和植物激素级联反应诱导的陷阱特异性表达中PR基因的差异表达和调控；(3)通过检查基因的出生-死亡阐明PR基因的进化机制。促进功能分化的选择压力变化、基因组结构背景和基因家族扩展机制。该研究得益于新的基因组组装，建立在初步RNA-seq数据的基础上，并为研究食肉植物的适应性基因组结构奠定了基础。该项目产生的数据也将促进未来致力于系统学、性状进化、发育和基因组进化的项目。对营养获取基因的研究不仅将增加对植物食肉性进化的理解，而且将有可能改变目前对基因家族进化动力学和基因表达驱动表型新颖性机制的理解。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。

The central goal of the proposed research is to examine how prey digestion among distantly-related carnivorous plants has evolved and is regulated. The remarkable capability of carnivorous plants to obtain nutrients from non-soil sources, namely insects, has independently arisen perhaps ten separate times in the flowering plants. The carnivorous habit involves attraction, capture, and digestion of prey, and this project focuses on the latter characteristic while specifically testing whether common plant defense proteins have been repeatedly repurposed for acquisition of essential nutrients. Strength in the research lies in the interdisciplinary approach in which multiple species will be compared to address this question. The research has significant potential to inform plant physiology, including studies of nutrition and functions of plant hormones. Additionally, outcomes of this proposal also have broad implications for understanding plant defense, and may result in the discovery of novel proteins for use in plant disease management and alternative technological applications. The project will enable training of graduate and undergraduate students from diverse and underrepresented backgrounds, and findings will be incorporated into undergraduate and graduate-level courses. Through established collaborations, the project will support public programs for K-12 students and adults aimed at teaching concepts related to biological evolution using charismatic carnivorous plants.The research will examine the extent co-option has played in the functional diversification and regulation of common plant defense proteins, specifically pathogenesis-related (PR) proteins, used in prey digestion among independently-evolved carnivorous plants. Using methods in comparative genomics, and a transcriptomics approach coupled with targeted treatments, the project aims to: (1) determine which digestive-functional genes are expressed within the traps of distantly-related Drosera and Pinguicula species, and if these loci are homologous to PR genes used in plant defense, (2) investigate differential expression and regulation of PR genes with trap-specific expression induced by prey, wound-signaling, and phytohormone cascades, and (3) elucidate the mechanisms by which PR genes have evolved by examining gene birth-death, changes in selection pressures promoting functional divergence, genome structural context, and mechanisms for gene family expansion. The research benefits from new genome assemblies, builds upon preliminary RNA-seq data, and lays the foundation for studies of adaptive genomic architecture across the carnivorous plants. Data resulting from the project will also facilitate future projects devoted to systematics, trait evolution, development, and genome evolution. A study of the genes underlying nutrient acquisition will not only add to an evolutionary understanding of plant carnivory, but will have the potential to transform present understanding of the mechanisms by which the evolutionary dynamics of gene families and gene expression drive phenotypic novelty.This 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.