Abstract Detail

Molecular Ecology

Todesco, Marco [1], Bercovich, Natalia [1], Kim, Amy [1], Imerovski, Ivana [1], Gregory, Owens [2], Dorado Ruiz, Oscar [1], Holalu, Srinidhi [3], Madilao, Lufiani [4], Jahani, Mojtaba [1], Légaré, Jean-Sébastien [5], Blackman, Benjamin [6], Rieseberg, Loren [7].

Hidden in plain sight: genetic basis and dual adaptive role of ultraviolet floral patterns in sunflowers.

Flower colour is one the most striking examples of adaptive diversity in plants. As remarkable as the variation that we can observe is, even more of it lays just outside our perception; many flowers accumulate ultraviolet pigments, which are invisible to us but can be seen by most pollinators.
This is particularly striking in sunflowers; while the inflorescences of all wild sunflowers appear uniformly yellow to the human eye, we observed extensive variation for the size of floral UV patterns, both between and within species. Using a combination of population genomics and molecular biology approaches, we showed that in the common sunflower, Helianthus annuus, this diversity is largely controlled by cis-regulatory variation at a single gene, HaMYB111, encoding a transcription factors that regulates accumulation of UV-absorbing flavonol glycosides.
Consistent with the well-established role of colour patterns in pollinator attraction, variation in UV patterns has a major impact on visitation rates from pollinators. However, we found that variation for floral UV patterns is also associated with environmental variables, especially relative humidity, across the range of wild H. annuus; flowers with larger UV patterns are found in drier environments, and show increased resistance to desiccation. This suggest that patterns of diversity for UV floral pigmentation are shaped by the interactions between abiotic factors (i.e. humidity and temperature) and biotic ones (i.e. pollinators), highlighting the complex nature of adaptive variation.

Related Links:
Publication

1 - University of British Columbia, Department of Botany, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
2 - University of Victoria, Department of Biology, Cunningham Building 202, BC, V8P 5C2, Canada
3 - University of California Berkeley, Department of Plant and Microbial Biology, Koshland Hall 111, Berkeley, CA, 94720, USA
4 - University of British Columbia, Michael Smith Laboratory and Wine Research Centre, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
5 - University of British Columbia, Department of Botany, 6270 University Boulevar, vancouver, BC, V6T 1Z4, Canada
6 - University Of California, Berkeley, Plant And Microbial Biology, 111 Koshland Hall #3102, Berkeley, CA, 94720, United States
7 - University Of British Columbia, Department Of Botany, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada

Keywords:
adaptation
Evolutionary biology
Pollinators
UV pigments
Abiotic stress
Functional genomics
MYB transcription factors
sunflower
Compositae
Wild relatives
Arabidopsis thaliana
Flower colour
GWAS
GEA.

Presentation Type: Oral Paper
Number: ME3003
Abstract ID:116
Candidate for Awards:None