Their sunny and vibrant summery vibe brightens up our lives.
Sunflowers may not be just beautiful to see, but they have an interesting hidden feature that could help us understand how we can adapt to climate changes.
That’s because an ultraviolet (UV) bullseye pattern — which is invisible to humans — not only helps their flowers attract pollinators but also enables the plant to respond to stresses such as drought or extreme temperatures.
Experts from the University of British Columbia (UBC) found that the same molecules that produce these UV patterns in sunflowers are also involved in helping the plant to regulate water loss.
They could be a key to understanding how plants adapt to climate change.
Discovery: Sunflowers can be more than pretty. They also display a UV bullseye pattern, which is a sign that plants may adapt to climate change. A study was done.
That’s because an ultraviolet bullseye pattern (pictured middle) — which is invisible to humans — not only helps their flowers attract pollinators but also enables the plant to respond to stresses such as drought or extreme temperatures
“Unexpectedly we found that sunflowers that grow in dry climates have larger UV bullseyes and that these flowers retain more water,” said Dr. Marco Todesco (a researcher at UBC’s botany department and biodiversity research center).
This suggests that plants can adapt to the drier conditions by using larger UV bullseyes.
In 2016, Dr. Todesco and two of his associates grew nearly 2,000 wild sunflowers from the university’s two species.
Researchers analysed the genomes of wild sunflowers in North America and measured their UV patterns. They found very distinct UV bullseyes.
The bullseye could be a thin or complete ring in some cases, but it can also cover the entire flower in other cases.
Bees visited larger bullseyes more often than other species, supporting earlier research.
HaMYB111 was the gene responsible for the majority of floral patterns that were unique to each individual, according to researchers.
This gene regulates the production of UV-absorbing flavonol chemicals, which help plants survive in extreme environments like drought and high temperatures.
Higher levels of this compound in larger floral patterns could reduce the amount that a sunshine evaporates from it. This can help to prevent excessive water loss.
According to the authors, in humid and hot climates, smaller UV-ray patterns could promote this evaporation. This would keep the plant cool, while avoiding excessive heat.
Researchers analysed the genomes of wild sunflowers in North America and measured their UV patterns. They found very distinct UV bullseye sizes.
Bees visited larger bullseyes more often than other species, supporting earlier research on the plant species.
Bees visited larger bullseyes more often than others, which supports previous research on other species of plants (stock image).
“Floral ultraviolet patterns may play at least two roles in adaptation,” Dr Loren Rieseberg said. She is a professor in Botany’s department and the Biodiversity Research Centre.
‘That’s not something you would necessarily expect a flower colour to do, and it exemplifies the complexity and efficiency of adaptation — solving two problems with a single trait.’
Sunflowers are cultivated for various purposes, including sunflower oil production, a roughly US$20billion (£14billion) industry in 2020.
Dr Todesco believes that this research will help to increase the knowledge on how to attract and maintain pollinators.
He added: “This research also helps us understand the adaptability of sunflowers to various temperatures and areas, which may be crucial in a warming environment.”
Additionally, the researchers want to know how HaMYB111 controls the size of ultraviolet bullseyes and how flavonol compound affect water loss.