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

这项拟议研究的中心目标是研究远亲食肉植物之间的猎物消化是如何进化和调控的。肉食性植物从非土壤来源，即昆虫中获得营养的非凡能力，在开花植物中独立出现了大约十次。食肉习性包括对猎物的吸引、捕获和消化，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改变用途以获取必要的营养。这项研究的优势在于跨学科的方法，在这种方法中，将对多种物种进行比较，以解决这个问题。这项研究对植物生理学有很大的潜力，包括对植物激素的营养和功能的研究。此外，这一建议的结果也对理解植物防御具有广泛的影响，并可能导致发现用于植物病害管理和替代技术应用的新蛋白质。该项目将对来自不同背景和代表性不足的研究生和本科生进行培训，研究结果将纳入本科生和研究生课程。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，旨在教授与使用有魅力的肉食性植物的生物进化相关的概念。该研究将研究共同选择在常见植物防御蛋白的功能多样化和调节中发挥的作用，特别是用于独立进化的肉食性植物的猎物消化的病程相关(PR)蛋白。利用比较基因组学的方法，结合靶向治疗的转录组学方法，该项目的目标是：(1)确定哪些消化功能基因在远缘关系的垂丝草属和海鞘属物种的陷阱中表达，以及这些基因是否与植物防御中使用的PR基因同源；(2)研究捕食、伤害信号和植物激素级联诱导的具有TRAP特异性表达的PR基因的差异表达和调控；以及(3)通过检测基因的出生-死亡、促进功能分化的选择压力的变化、基因组结构背景和基因家族扩大的机制来阐明PR基因的进化机制。这项研究得益于新的基因组组合，建立在初步的RNA-SEQ数据基础上，并为研究肉食性植物的适应性基因组结构奠定了基础。该项目产生的数据还将为未来致力于系统学、特征进化、发育和基因组进化的项目提供便利。对营养获取的基因的研究不仅将增加对植物食肉动物的进化理解，而且将有可能改变目前对基因家族的进化动态和基因表达驱动表型新颖性的机制的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.