Collaborative research: RUI: a phylogenomic study of a hyper-diverse flowering plant lineage, subfamily lamioideae (lamiaceae)

This three-year, $393,461 project grant from the National Science Foundation's Biological Sciences program (CFDA 47.074) supports a collaborative research effort to build a robust phylogenetic framework of the hyper-diverse flowering plant subfamily Lamioideae (Lamiaceae). The awardee, Missouri Western State University, will utilize next-generation sequencing approaches including targeted enrichment, transcriptomics, and broad taxonomic sampling to circumscribe major clades within Lamioideae and determine relationships. This will enable exploration of patterns linking diversification events to shifts in biogeography, genome dynamics, and trait evolution. The project also aims to estimate timing of key evolutionary events and diversification rates. It provides extensive education and training opportunities at multiple levels, including for 12 undergraduate students from Missouri Western State University. Outcomes will improve understanding of comparative biology, product discovery, and conservation efforts for endangered species within this near cosmopolitan plant subfamily.

Abstract

Understanding the evolutionary processes that lead to speciation remains a fundamental challenge in biology. As the sixth largest flowering plant family, the mint family (lamiaceae) is exceptionally important ecologically, ethnobotanically, and floristically. Within the mint family, the second largest subfamily, the lamioid mints (lamioideae), serves as an excellent model for exploring global patterns of plant diversification and evolutionary radiation, or a rapid increase in the number of species in a clade. This research will use high throughput DNA sequencing technologies to build a robust understanding of evolutionary relationships in the lamioid mints. The findings from this project will be of broad value to systematists, evolutionary biologists, and ecologists by helping close gaps in our fundamental understanding of how plants diversify, including the evolution of early flowering plants and colonization of newly formed habitats, such as volcanic islands. Information gathered from this project will also improve our knowledge of the comparative biology of lamioid mints, guide new product discovery, and aid in the development of conservation measures for endangered species. This project incorporates extensive opportunities for education and career training at multiple levels, including high school teachers, undergraduate students, a postdoctoral researcher, and an early-career female faculty. The project team will offer public seminars about lamioid mints, highlighting their research findings and broader implications. An important component of this project is to train and mentor undergraduate students, and twelve undergraduate students from missouri western state university will become actively involved in various aspects of this project. The lamioid mints, which have been categorized into 13 tribes, have a near cosmopolitan distribution, with most taxa found in the old world and only two lineages having colonized the new world and hawaiian islands. Despite this widespread distribution and diversity, a solid phylogenomic framework of the lamioid mints, from which patterns of diversification and links to shifts in distribution, ecology, and genome dynamics can be explored, is still lacking. This project will utilize next-generation sequencing approaches involving targeted enrichment, transcriptomics, and broad taxonomic sampling from field and herbaria across the US to build a robust phylogenetic platform of the lamioid mints. The following major goals will be accomplished: 1) circumscribe the major clades of lamioideae and their interrelationships and make necessary taxonomic changes, including determining the placement of the two tribes comprising new world members, stachydeae and synandreae, and the basal tribes, gomphostemmateae and pogostemoneae; 2) estimate the timing of key evolutionary events and rates of diversification; 3) link diversifications in lamioideae, particularly within stachydeae and synandreae, with shifts in biogeography, whole genome and gene duplication, and character trait evolution to identify possible key innovations and apparent repeated evolution of morphological characters. 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.