The evolution of Montiaceae: integrating phylogeny, life history, and physiology to understand a global ecological radiation

Yale University, New Haven CT

Investigators

Abstract

Many groups of organisms contain closely related species that are specialized to live in very distinct and challenging environments. Understanding how these adaptations have evolved over time is critical to understanding the evolutionary history of life on Earth. It also improves predictions of future outcomes of ongoing global change. Some plant groups include multiple transitions between extreme desert and mountain habitats. These transitions have been correlated with shifts in individual lifespan and the timing of growth and reproductive events. The Montiaceae is a plant family of ~250 species of annual and perennial herbs with centers of diversity in Australia and Western North and South America. They are ecologically and morphologically diverse, with multiple transitions between high mountain, Mediterranean, and desert environments. Most investigated species also possess a special form of photosynthesis that, when engaged, allows them to be more efficient in their growth. This project will build a complete family tree for this group of plants. The resulting history will be used to reconstruct how this plant family repeatedly adapted to different extreme environments. Investigation will particularly focus on how changes in photosynthetic physiology are integrated with other shifts in lifespan and reproduction. The project will provide exceptional training from the undergraduate to the post-doctoral levels. Training activities will include a virtual hybrid seminar series and a post-baccalaureate scholars program. The project strengthens a highly collaborative international partnership with participants in the United States, Argentina, Chile, and Peru. The researchers will also run a training workshop in specimen georeferencing and herbarium data management at Universidad Nacional Mayor de San Marcos Herbarium, the largest herbarium in Peru, further enabling global access to these important collections. The researchers will further develop the Montiaceae as a model clade for plant evolutionary biology. This project will focus on the evolutionary assembly of annual and perennial life history syndromes, how photosynthetic physiology may be better integrated into these syndromes and extend a newly proposed model of character evolution (stress-induced evolutionary innovation, “SIEI”) to plants. This work will include extensive field collections and greenhouse studies of drought response, gene expression analyses, and photosynthetic physiology. They will generate a completely sampled phylogeny for Montiaceae, focusing efforts on the taxonomically difficult Cistanthe-Calyptridium-Montiopsis clade and initiating work on a full taxonomic revision of Cistanthe sensu stricto. In the process, they will develop a new bioinformatics pipeline that will optimize the merging of novel and historical genomics-scale datasets for subsequent phylogenetic analysis. 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.