Cojocaru Ruxandra, Mannix Oonagh, Capron Marie, Miller C Giles, Jouneau Pierre-Henri, Gallet Benoit, Falconet Denis, Pacureanu Alexandra, Stukins Stephen
ESRF-The European Synchrotron, 71 Avenue des Martyrs, Grenoble, France.
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany.
Sci Adv. 2022 Feb 11;8(6):eabd0892. doi: 10.1126/sciadv.abd0892. Epub 2022 Feb 9.
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.
花粉粒的外层，即外壁，在陆地植物生命的存活中起着关键作用。然而，不同植物类群的外壁结构仍然是个谜。在此，对现代和化石针叶树双气囊花粉进行了研究，以探究花粉壁的详细三维结构和特性。利用X射线纳米断层扫描和体积电子显微镜提供高分辨率图像，揭示出一种固体纳米泡沫结构。原子力显微镜测量被用于将花粉壁与其他天然和合成泡沫进行比较，并证明这种花粉类型的花粉壁机械性能在化石标本中能保留数百万年。这种坚固生物材料的微观结构在材料科学中有潜在应用，也有助于我们理解针叶树和其他植物在地质时期的进化成功。
