Research
Columbine flower development & evolution
Kramer Lab, Harvard University
My Ph.D. work focused on the unique 3-D petal nectar spur of Aquilegia (columbine), which varies dramatically in shape and size among columbine species with different pollination syndromes. The spurs of bee-pollinated species are short and curved (purple flower on the left), while those of hummingbird-pollinated species are long and straight (red flower on the right). With the support of an NSF Graduate Research Fellowship, I used a comparative developmental approach combined with QTL mapping and RNA-seq to illuminate the morphological and genetic underpinnings of this phenomenon. I defended my dissertation entitled “Exploring the development and diversification of the unique Aquilegia nectar spur” in February 2022.
You can watch my defense seminar here.
Publications & Presentations:
Edwards, M. B. et al. "Complex developmental and transcriptional dynamics underlie pollinator‐driven evolutionary transitions in nectar spur morphology in Aquilegia (columbine)." American journal of botany 109.9 (2022): 1360-1381. https://doi.org/10.1002/ajb2.16046
You can watch the Science IRL episode about it here.
Edwards, M. B. et al. “Genetic architecture of floral traits in bee- and hummingbird-pollinated sister species of Aquilegia (columbine).” Evolution (2021). http://doi.org/10.1111/evo.14313
This is my first first-author paper! You can watch the Science IRL episode about it here.
Edwards, M. B. et al. “A developmental & transcriptional framework for pollinator-driven evolutionary transitions in petal spur morphology in Aquilegia (columbine).” Oral presentation, Botany Conference 2021. Recipient of the Esau Award for best student presentation in development.
Ballerini, E.S., Min, Y., Edwards, M. B…Hodges, S.A. "POPOVICH, encoding a C2H2 zinc-finger transcription factor, plays a central role in the development of a key innovation, floral nectar spurs, in Aquilegia." Proceedings of the National Academy of Sciences of the United States of America 117.36 (2020): 22552-22560.
Edwards, M. B. et al. “Genetic architecture of nectar spur traits in bee- and hummingbird-pollinated sister species of Aquilegia (columbine).” Oral presentation, Botany Conference 2020.
Edwards, M. B. et al. “Exploring the developmental and genetic basis of complex petal morphologies in bee- and hummingbird-pollinated Aquilegia (columbine).” Oral presentation, Botany Conference 2019.
Nitrogen signaling systems biology
Coruzzi Lab, NYU
As an assistant research scientist, I helped characterize genes involved in the plant nitrogen signaling network. After transiently expressing candidate transcription factors (TFs) in Arabidopsis protoplasts and exposing the cells to nitrogen, I prepared RNA-seq and ChIP-seq libraries so we could identify TF regulatory and binding targets. Many of these targets are crucial to plant nitrogen processing, and the data generated by my experiments helped the lab to elucidate a “hit-and-run” model for TF rapid nitrogen response.
Publications:
Varala, K., Marshall-Colón, A., Cirrone, J., Brooks, M.D., Pasquino, A.V., Léran, S., Mittal, S. Rock, T.M., Edwards, M.B…Coruzzi, G.M. “Temporal transcriptional logic of dynamic regulatory networks underlying nitrogen signaling and use in plants.” Proceedings of the National Academy of Sciences of the United States of America 115.25 (2018): 6494-6499
Doidy, J., Li, Y., Neymotin, B., Edwards, M.B...Coruzzi, G.M. “’Hit-and-Run’ transcription: de novo transcription initiated by a transient bZIP1 ‘hit’persists after the ‘run.’” BMC Genomics (2016) 17:92
Li, Y., Mukherjee, I., Thum, K., Tanurdzic, M., Katari, M., Obertello, M., Edwards, M.B.…Coruzzi, G.M. "The histone methyltransferase SDG8 mediates the epigenetic modification of light and carbon responsive genes in plants." Genome Biology 16.1 (2015): 79.
Para, A., Li, Y., Marshall-Colon, A., Varala, K., Francoeur, N.J., Moran, T.M., Edwards, M.B.…Coruzzi, G.M. "Hit-and-run transcriptional control by bZIP1 mediates rapid nutrient signaling in Arabidopsis." Proceedings of the National Academy of Sciences of the United States of America 111.28 (2014): 10371-10376.
Angraecoid orchid molecular systematics
Plunkett Lab, New York Botanical Garden
This project was a collaboration between the Cullman Program for Molecular Systematics at NYBG, the Missouri Botanical Garden, and the University of Youndé in Cameroon. As the project research assistant I was responsible for database management, DNA extractions from orchid tissue sent to us by our collaborators, PCRs of informative loci, and sequence data analysis for a subset of species. My work demonstrated the monophyly of the Angraecoid orchid genus Ancistrorhynchus and that it could be divided into two sections, which supported recent taxonomic revisions based on floral morphology. While at NYBG, I also had the chance to assist with several other molecular systematics projects, including work on Bignoniaceae.
Publications & Presentations:
Verlynde, S., D’Haese, C.A., Plunkett, G.M., Simo-Droissart, M., Edwards, M.B…Stévart, T. "Molecular phylogeny of the genus Bolusiella (Orchidaceae, Angraecinae)." Plant Systematics and Evolution 304.2 (2018): 269-279.
Callmander, M.W., Phillipson, P.B., Plunkett, G.M., Edwards, M.B., and Buerki, S. “Generic delimitations, biogeography and evolution in the tribe Coleeae (Bignoniaceae), endemic to Madagascar and the smaller islands of the western Indian Ocean.” Molecular Phylogenetics & Evolution 96 (2016): 178-186.
Edwards, M.B. et al. “Taxonomic revision and molecular phylogeny of Ancistrorhynchus (Orchidaceae), an Angraecoid genus from continental Africa.” Oral presentation, Botany Conference 2013.
Shoot apical meristem transcriptomics in horsetails
Scanlon Lab, Cornell University
My undergraduate research focused on the unique shoot apical meristem (SAM) of Equisetum arvense (horsetail), which is characterized by a large triangular apical cell (AC). A fundamental question in plant developmental biology is whether this AC is solely responsible for meristematic activity, or if the rest of the SAM contributes as well. Supervised by then-PhD student Margaret Frank, we sought to answer these questions by using a comparative transcriptomics approach across tissue types in the SAM as well as between species. We found that the AC is transcriptionally distinct, indicating that the AC has a separate function from the rest of the meristem. Not only that, Equisetum SAM transcriptional profiles are largely non-overlapping with those of Selaginella (a lycophyte with an AC-type SAM), supporting the hypothesis that their shared meristem morphology is convergent in origin.
Publications:
Frank, M.H., Edwards, M.B…Scanlon, M.J. "Dissecting the molecular signatures of apical cell‐type shoot meristems from two ancient land plant lineages." New Phytologist 207.3 (2015): 893-904.
