NSF Postdoctoral Fellowship in Biology FY 2021: Uncovering the regulatory mechanisms for a genetic switch between anthocyanin and carotenoid pigmentation in monkeyflowers

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2021. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Lauren Stanley is “Uncovering the regulatory mechanisms for a genetic switch between anthocyanin and carotenoid pigmentation in monkeyflowers.” The host institution for the fellowship is Michigan State University and the sponsoring scientist is Dr. David Lowry.

A major goal of plant biology is to understand the genetic mechanisms regulating the production of important pigments, including anthocyanins (red, purple, or blue) and carotenoids (yellow, orange, or red). This work will use the monkeyflower species Mimulus whitneyi, which has co-occurring plants with either purple or yellow flowers, to identify the regulatory gene responsible for this color difference.

The research will also uncover the genetic network controlled by this regulator and assess whether it has repeated use in the evolution of flower color transitions across multiple species. This integrative approach will advance our understanding of plant pigmentation, which is crucial to photosynthesis, stress tolerance, defense against herbivores and pathogens, and reproduction.

Anthocyanins and carotenoids also play a key role in human health, and thus understanding the genetic mechanisms underlying their regulation has a direct application for the nutritional improvement of crop plants via genetic engineering. This research will provide the Fellow with training in bioinformatics, population genomics, and epigenomics methods to build a comprehensive research program.

To broaden the impact of this work, the Fellow will contribute to STEM education for students in Flint and Detroit, Michigan through the development of a Mimulus-based education module for underserved middle and high school classrooms. The module will focus on floral pigmentation, pollinator vision, and plant fitness. Materials generated for this module will made publicly available on the CREATE Open Science webpage.

This research aims to identify the regulatory mechanisms underlying the coordinated evolution of two key plant pigmentation pathways. Specifically, the project will focus on the genetic basis for a floral purple-to-yellow (anthocyanin-to-carotenoid) color transition using the polymorphic monkeyflower species Mimulus whitneyi. Aim 1 of the research will identify and validate a master regulatory gene underlying the purple/yellow flower color polymorphism in M. whitneyi by generating a high-quality reference genome, performing whole-genome pooled sequencing of purple and yellow morphs, and genotyping across eleven natural populations.

Aim 2 will generate a model for the regulation and co-regulation of the anthocyanin and carotenoid biosynthesis pathways by characterizing gene networks and regulatory elements in purple and yellow morphs using RNA-seq, gene network analysis, and ATAC-seq. Aim 3 will illuminate the evolutionary history of color transitions in the Mimulus genus by investigating the genetic basis for convergent purple/yellow flower color polymorphisms in natural populations of three additional monkeyflower species.

All sequencing data will be made publicly available through NCBI and Phytozome, with bioinformatics pipelines and custom scripts available through GitHub. Voucher specimens will be deposited at the Michigan State University Herbarium, where they will be digitized and documented in the iDigBio and Symbiota databases.

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.