Researchers at Cambridge’s Sainsbury Laboratory reveal that hibiscus flowers use a ‘paint by numbers’ strategy in petal formation to attract pollinators. This discovery could shed light on the evolutionary mechanisms behind the diverse floral patterns in nature.
A new study from the University of Cambridge’s Sainsbury Laboratory has revealed that flowers, including the common hibiscus, use sophisticated pre-patterned designs in petal formation to attract pollinators such as bees. These intricate designs, resembling a ‘paint by numbers’ system, could provide new insights into the evolution and biodiversity of plant life.
Edwige Moyroud and her team examined three varieties of hibiscus flowers — H. richardsonii, H. trionum and a transgenic line of H. trionum — with varying bullseye patterns. These patterns, consisting of dark purple centers surrounded by white, were found to develop very early in the petal’s life, long before any visible colors appeared.
“At the earliest stage we could dissect, the petals have around 700 cells and are still greenish in color, with no visible purple pigment and no difference in cell shape or size,” lead author Lucie Riglet said in a news release. “When the petal further develops to 4000 cells, it still does not have any visible pigment, but we identified a specific region where the cells were larger than their surrounding neighbors. This is the pre-pattern.”
Their research revealed that bees prefer flowers with larger bullseyes, flying 25% faster between such flowers. This increased efficiency benefits both bees and plants, enhancing pollination success. The study, published in the journal Science Advances, indicates that these pre-patterning strategies could have deep evolutionary roots, influencing the diversity of floral patterns across different species.
“If a trait can be produced by different methods, it gives evolution more options to modify it and create diversity, similar to an artist with a large palette or a builder with an extensive set of tools. By studying how bullseye patterns change, what we are really trying to understand is how nature generates biodiversity,” Moyroud, a group leader at the Sainsbury Laboratory who investigates pattern formation in petals. said in the news release.
The researchers think these pre-patterning strategies allow plants to precisely control and modify the shape and size of petal patterns, offering potential advantages in the race to attract pollinators. They plan to identify the signals responsible for these early designs and explore if similar mechanisms are used in other plant organs like leaves.
This research doesn’t just advance our understanding of plant biology; it also underscores the intricate connections between plants and their environments. The study highlights how precise natural designs can play a crucial role in the survival and evolution of species.
For instance, H. richardsonii, with the smallest bullseye of the hibiscus plants studied, is critically endangered in its native New Zealand. H. trionum, although also found in New Zealand, is more widespread globally and considered a weedy naturalized plant in places like North America.
The findings could pave the way for further investigations into whether larger bullseyes enhance pollinator attraction and boost reproductive success in various plant species. For now, this research serves as a fascinating reminder of nature’s complexity and adaptability.