A biological nanofoam: The wall of coniferous bisaccate pollen.

Ruxandra Cojocaru (1) , Oonagh Mannix (1, 2) , Marie Capron (1) , C Giles Miller (3) , Pierre-Henri Jouneau (4) , Benoit Gallet (5) , D. Falconet (6) , Alexandra Pacureanu (1) , Stephen Stukins (3)

1 ESRF - European Synchrotron Radiation Facility [Grenoble]
2 Helmholtz-Zentrum Berlin für Weiche Materie und Funktionale Materialien
3 NHM - The Natural History Museum [London]
4 MEM - Modélisation et Exploration des Matériaux
5 IBS - UMR 5075 - Institut de biologie structurale
6 LIPID

The outer layer of the pollen grain, the exine, plays a key role in the survival of terrestrial plant life. However, the exine structure in different groups of plants remains enigmatic. Here, modern and fossil coniferous bisaccate pollen were examined to investigate the detailed three-dimensional structure and properties of the pollen wall. X-ray nanotomography and volume electron microscopy are used to provide high-resolution imagery, revealing a solid nanofoam structure. Atomic force microscopy measurements were used to compare the pollen wall with other natural and synthetic foams and to demonstrate that the mechanical properties of the wall in this type of pollen are retained for millions of years in fossil specimens. The microscopic structure of this robust biological material has potential applications in materials sciences and also contributes to our understanding of the evolutionary success of conifers and other plants over geological time.

Domaines: Botanique

Ruxandra Cojocaru, Oonagh Mannix, Marie Capron, C Giles Miller, Pierre-Henri Jouneau, et al.. A biological nanofoam: The wall of coniferous bisaccate pollen.. Science Advances , 2022, 8 (6), pp.eabd0892. ⟨10.1126/sciadv.abd0892⟩. ⟨hal-03612090⟩