What makes pollen walls the most durable biological material?

Sporopollenin is the most durable biological material in nature and is a major component of the outer wall of pollen.

Scientists at the Natural History Museum (UK) and the ESRF are investigating the structure of the pollen wall this past weekend, on ID16A, to find out why this material is so resistant.

This experiment would not have taken place if chance, luck, but mostly curiosity had not played a major role in this story. ESRF post-doctoral researcher Ruxandra Cojocaru was talking to colleagues at the facility, looking for an appropriate material for a sedimentation study. Many discussions later, she ended up finding what she needed at the Natural History Museum in London, where curator and pollen specialist Stephen Stukins works.

Several exchanges later, and with an approved proposal for a different project than the original, they are now on ID16A to study the structure of pollen at nanolevel. “Throughout time, there have been species that have disappeared, yet the major plant groups have been relatively resistant to extinction. This may be due to the resistant sporopollenin material that was adapted for plant survival on land, especially exposure to UV radiation”, explains Stukins. With fellow NHM microfossil curator Giles Miller, he has brought fossil samples of Bathonian age, from the Jurassic era, that are part of the museum collection. “What we want to see is the structure of pollen, and more precisely of the sporopollenin outer wall. This is an almost inert biological polymer and we think it is key to the properties of pollen”, says Stukins.

>Read more on the European Synchrotron website

Image: the sample in its set-up at the European Synchrotron.
Credit: Montserrat Capellas Espuny