Pollen Origami Key to Plant Sex

Though it might be small solace to springtime sneezers, a new study shows grains of pollen to be biomechanical marvels. Their weblike outer shell folds like origami as grains leave a flower, sealing holes and preventing sperm inside from drying. As pollen arrives at another flower, the shell relaxes and unfolds, allowing fertilization to take […]

pollen

Though it might be small solace to springtime sneezers, a new study shows grains of pollen to be biomechanical marvels.

Their weblike outer shell folds like origami as grains leave a flower, sealing holes and preventing sperm inside from drying. As pollen arrives at another flower, the shell relaxes and unfolds, allowing fertilization to take place.

pollen2The folding process, driven by forces generated by water loss, is called harmomegathy. It's known to scientists, but the underlying principles are expanded and quantified in a paper published April 19 in the Proceedings of the National Academy of Sciences.

Researchers led by Rockefeller University physicist Eleni Katifori used an electron microscope to photograph different types of pollen, then made computer models that revealed the mathematical patterns guiding their transformations.

Pollen comes in hundreds of sizes and shapes, and the design principles "can serve as a source of tested solutions for the development of smart surfaces that can adapt to their environment," wrote the researchers.

One possible use for smart surfaces is in drug delivery. Perhaps scientists will someday use pollen design to inspire a better antihistamine pill.

Images: 1) Scanning electron microscope image of Lilium longiflorum pollen folding/PNAS.
2) SEM image and folding pattern of Euphorbia millii pollen/PNAS.

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Citation: "Foldable structures and the natural design of pollen grains.” By Eleni Katifori, Silas Alben, Enrique Cerda, David R. Nelson, and Jacques Dumais. Proceedings of the National Academy of Sciences, Vol. 107. No. 16, April 20, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.