BRC-BIO: Using the genus Aquilegia to develop a multidisciplinary approach to study the evolution and ecology of nectar variation

University Enterprises, Incorporated, Sacramento CA

Investigators

Abstract

Most flowering plants rely on animal pollinators to reproduce. Given the importance of attracting pollinators in order to complete their life cycle, many plants have evolved to produce floral nectar, composed of sugars and other nutrients that serves as a reward for pollinators. Different animal pollinators (e.g., bees, birds, or moths) have different metabolic needs, and previous work has shown that plants adapted to different pollinators vary in the amount and the biochemical composition of the nectar that they produce. However, little is known about the genes that control this variation in nectar production. This work combines biochemical profiling of nectar components produced by closely related plants that have adapted to different pollinators with genetic analyses in order to identify the genes that control variation in nectar volume and biochemistry. As around 35% of agricultural crops rely on animal pollinators, identifying genes that control important aspects of nectar variation could help improve nectar quality and pollination efficiency to increase crop production. In addition, this work provides numerous opportunities to train both undergraduate and master’s students to conduct hands on research in fields such as genomics, metabolomics, and bioinformatics in preparation to pursue advanced degrees or obtain careers in STEM fields. Plant-pollinator interactions are a driving force of floral diversification with animal pollinators, exerting strong selection on floral trait evolution that can contribute to reproductive isolation and speciation. Prior focus on floral adaptation to animal pollinators has largely focused on morphological traits such as color and shape. However, floral nectar plays an important role in pollinator adaptation, and is regulated by both genetic and environmental processes. Much remains to be discovered about the genetic and environmental factors influencing nectar trait variation and very few studies have incorporated metabolomic data when examining nectar adaptation to different animal pollinators. This research will: 1) describe nectar characteristics of four Aquilegia species adapted to different animal pollinators (e.g., bee, hummingbird, hawk moth) using a combination of developmental assays, transcriptomics, and metabolomics; 2) use high-resolution genetic mapping to identify loci controlling variation in nectar characteristics, including metabolites, between closely related taxa adapted to different animal pollinators, A. formosa (hummingbird) and A. pubescens (hawk moth); and 3) explore how environmental factors such as temperature and humidity affect nectar production and composition in two Aquilegia species using a combination of studies in wild populations and under controlled conditions. Together, these investigations will be the most comprehensive set of analyses yet implemented to explore the genetic and environmental factors influencing the evolution of nectar metabolomic variation in a plant system known for its floral adaptations to different animal pollinators. 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.