Research
How does ecology influence genome size and trait evolution?
There has been much interest in understanding how various ecological pressures, such as abiotic stress, can ultimately affect the evolution of transposable elements, genome size, and influence trait and plant fitness. We are currently interested in delving deeped into this question, using the family Solanaceae as a model. Our lab is starting to explore this question in various key groups of the genus Solanum, using a multidisciplinary approach.
Interested in working on this topic? Contact the lab (read here first).
Population genomics of a wild crop relative of tomatoes, S. chilense
Working on families that are rich in crop species have led me to become interested in understanding how we could use their wild relatives to help address questions relevant to food security and improving the resilience of their domesticated relatives. I've had the opportunity to start exploring these questions by examining the diversity of disease resistance genes in S. chilense, a wild crop relatives of the tomato found from 0 to 3000 m in altitude in southern Peru and Northern Chile, and examining the importance of allelic diversity vs. presence-absence variation across populations growing in different environments.
I am currently pursuing work on this species, by examining if we can use herbaria to look at the evolution through time of interested in examining the evolution of loci related to both abiotic and biotic stress resistance, and answer questions about conservation genomics of this species, which holds key agrigenomic resources for the improvement of tomato crops.
I will be expanding in this research area, focusing on more wild species in the genus Solanum that span diverse ecological gradients. Interested in working on this topic? Contact the lab (read here first).
Macroevolution and biogeography
What are the mechanism and processes behind the diversification of plants over large time scales? I am interested in both understanding what are the factors that explain the distribution of species across various regions and what historical processes might have influenced these distributions, as well as understand what are the factors that might have driven evolutionary innovation in traits. Such studies ultimately has pratical implications for conservation biology, ecology and understanding the consequences of environmental change on biodiversity.
Select publications:
Gagnon, E., Moonlight, P.W., Knapp, S., Lehmann, C.E.R., Särkinen, T. (2023) Functional and ecological diversification of underground organs in Solanum. Frontiers in Genetics, RT: Solanaceae VIII: Biodiversity, Climate change and Breeding. 14. Doi: 10.3389/fgene.2023.1231413
Gagnon, E., Ringelberg, J.J., Lewis, G.P., Bruneau, A., Hughes, C.E. (2019) Global Succulent Biome phylogenetic conservatism across the pantropical Caesalpinia Group (Leguminosae). New Phytologist, 222: 1994–2008.
** Publication accompanied by a commentary: Donoghue, M.J. (2019) Adaptation meets dispersal: legumes in the land of succulents. New Phytologist, 222: 1667-1669.
Phylogenomics, systematics and species delimitation
How many species of angiosperms are there on Earth, and how are they related? I am interested in using phylogenomic analyses to understand the evolutionary history and diversity of plants, to shed light light on their evolutionary trajectories and adaptive strategies, but also to improve species delimination and botanical classification. Such insights not only deepen our knowledge of plant evolution but also have practical implications for agriculture, conservation, and ecosystem management.
Various projects over the year have focused on various clades of the economically and ecologically important plant families Leguminosae/Fabaceae and Solanaceae.
Select publications:
Rees, M., Neaves, L.E., Lewis, G.P., de Lima, H.C. and Gagnon, E. (2023) Phylogenomic and morphological data reveal hidden patterns of diversity in the national tree of Brazil, Paubrasilia echinata. American Journal of Botany. 110(11): e16241.
Gagnon, E., Hilgenhof, R.*, Orejuela, A., Sablok, G., Aubriot, X., Giacomin, L., Gouvêa, Y., Bohs, L., Dodsworth, S., Maurin, O., Forest, F., Poczai, P., Knapp, S., Särkinen, T. (2022) Phylogenomic data reveals hard polytomies in the large genus Solanum (Solanaceae). American Journal of Botany, 109(4): 580-601.
Gagnon, E., G.P. Lewis, C.E. Hughes, L.P.de Queiroz & A. Bruneau (2016). A new generic system for the pantropical Caesalpinia group (Leguminosae). Phytokeys 71: 1-160.
Gagnon, E., Hughes, C.E., Lewis, G.P., Bruneau A. (2015) A new cryptic species in a new cryptic genus in the Caesalpinia group (Leguminosae) from the seasonally dry inter-Andean valleys of South America. Taxon, 64(3): 468–490.
** Porsild-Consaul Award 2015 – best article on systematics written by a graduate student in Canada.