Nonslip role for petal cells

Conical cells on the petals of most flowering plants appear to play a much more grounding role for pollinating bees than scientists have previously assumed. Bee landing on snapdragonImage: Don Manning and Beverley GloverUniversity of CambridgeAccording to a study to be published in the June 9 issue of Current Biology, these cone-shaped cells on the surface of petals appear to provide insect pollinators with secure footing while perched on the plant. "Most people assumed that [conical cells] p

Written byJef Akst

| 2 min read

Save for Later

Conical cells on the petals of most flowering plants appear to play a much more grounding role for pollinating bees than scientists have previously assumed.

Bee landing on snapdragon
Image: Don Manning and Beverley Glover
University of Cambridge

According to a study to be published in the June 9 issue of Current Biology, these cone-shaped cells on the surface of petals appear to provide insect pollinators with secure footing while perched on the plant. "Most people assumed that [conical cells] played a role primarily in visual communication," said linkurl:David Baum,;http://www.botany.wisc.edu/baum/dbaum.htm plant evolutionary biologist at the University of Wisconsin-Madison, who did not participate in the research. It was never entirely clear what conical cells were for; one hypothesis held that by modifying the spectral properties of the petal, the cells enabled the plant to appear brighter to pollinators. In this study, "they show the conical cells help provide more friction which allows bees to get better footing." "I think this is an interesting and unique study," said linkurl:Geraldine Wright,;http://www.ncl.ac.uk/ion/staff/profile/jeri.wright neuroethologist at Newcastle University, also not a co-author. "This is essentially a biophysical parameter that may have been overlooked before now." By comparing two white snapdragon mutants -- a normal, conical-celled plant and a visually-identical, flat-celled form -- plant scientist linkurl:Beverley Glover;http://www.plant-biology.com/Beverley-Glover.php of the University of Cambridge and colleagues determined that bumblebees were able to detect these minute differences in petal surface structure (along the order of 10 micrometers). Indeed, when the textured flowers were stocked with 30% sucrose and the smooth flowers with a bitter quinine solution, the bees quickly learned to drink only from the plants with textured petals, reaching an accuracy of over 80% in just 20 visits. To test if bees prefer the conical-celled petals when all the flowers were stocked with 30% sucrose, the researchers used two colored lines of snapdragons -- the bright magenta, wild-type with conical cells on the epidermis of the petals and a paler pink, mutant line with flat-celled petal surfaces. Interestingly, while the bees showed no preference for the conical-celled surfaces when the flowers were horizontal, they chose to land on the textured wild-type flower significantly more often when the flowers were presented vertically, suggesting that they only prefer the conical cells when it is difficult to land on the flower. When the flower is vertical, Glover said, it's not very energetically efficient for bees to feed on the flat-celled flowers. "Their legs are scrambling as they do it, and their wings keep beating...like a mountain climber trying to find a hold on a vertical mountain side." Furthermore, because flat cells reflect more white light, the color of petals lacking conical cells appears diluted. "We think the color difference is something that bees might be able to learn as a cue," Glover said. "This is a great example of doing the hands-on manipulative experimentation to evaluate the adaptive value of an interesting trait," Baum agreed. The next step "is a phylogenetically structured survey to see if lineages that have lost conical cells tend to be those that switched to hovering animal pollinators."
**__Related stories:__***linkurl:A bee's life;http://www.the-scientist.com/article/display/55032/
[October 2008]*linkurl: Making sense of floral scents;http://www.the-scientist.com/blog/display/54980/
[28th August 2008]*linkurl: Flower power in motion;http://www.the-scientist.com/blog/display/54634/
[8th May 2008]

Meet the Author

Jef Akst

Jef (an unusual nickname for Jennifer) got her master’s degree from Indiana University in April 2009 studying the mating behavior of seahorses. After four years of diving off the Gulf Coast of Tampa and performing behavioral experiments at the Tennessee Aquarium in Chattanooga, she left research to pursue a career in science writing. As The Scientist's managing editor, Jef edited features and oversaw the production of the TS Digest and quarterly print magazine. In 2022, her feature on uterus transplantation earned first place in the trade category of the Awards for Excellence in Health Care Journalism. She is a member of the National Association of Science Writers.

View Full Profile

Nonslip role for petal cells

The Scientist ARCHIVES

Become a Member of

Meet the Author

Jef Akst

Related Research Resources

Why Do We Feel Butterflies in the Stomach?

Research Resources

Podcasts

Webinars

Videos

Infographics

eBooks

Long-Read RNA Sequencing Reveals a Regulatory Role for Splicing in Immunotherapy Responses

Research Roundtable: The Evolving World of Spatial Biology

Exploring the State of the Art in Gene Editing Techniques

Simplifying Early Alzheimer’s Disease Diagnosis with Blood Testing

Products

Product News

LabVantage Solutions Awarded $22.3 Million U.S Customs and Border Protection Contract to Deliver Next-Generation Forensic LIMS

Evosep Unveils Open Innovation Initiative to Expand Standardization in Proteomics

SPT Labtech and Alithea Genomics Collaborate to Automate Ultra Sensitive Single-Cell Transcriptomic Workflows

OGT expands MRD detection capabilities with new SureSeq Myeloid MRD Plus NGS Panel