X-ray computed tomography, or micro-CT, has crossed the boundary of geology to establish itself in plant biology laboratories. Researchers have managed to generate three-dimensional models of pollen grains with sub-micron resolution, allowing observation of exine ornamentation and internal cavities without the need for physical sections or metallization. This breakthrough opens a direct window into the microscopic architecture of plants.
Workflow: from synchrotron scanning to polygonal mesh 🔬
The process begins with fixing and mounting the pollen in a glass capillary. A synchrotron or laboratory micro-CT with a high-energy X-ray source is used. Between 900 and 1800 rotational projections are acquired. Reconstruction software (such as Octopus or NRecon) generates a voxelized volume. Then, using segmentation algorithms based on density thresholds, the grain structure is isolated. Finally, tools like Avizo or Dragonfly convert the volume into a polygonal mesh exportable to Blender or Unity. The technical key lies in avoiding ring artifacts and correcting phase dispersion, as pollen has a very low absorption coefficient.
Pollen as a 3D climate witness 🌍
Beyond aesthetic beauty, these models allow quantifying the exact volume of air chambers (sacci) in conifers, a direct indicator of atmospheric pressure at the time of grain formation. Paleobotanists already use this data to reconstruct the altitude of Miocene ecosystems. In allergology, tomography allows distinguishing morphologically identical species under the optical microscope, improving predictive maps of allergenic pollens. 3D visualization not only beautifies science but makes it quantifiable.
How can micro-CT of pollen grains reveal patterns of evolutionary adaptation in plant species that were previously invisible to traditional microscopy?
(PS: fluid physics for simulating the ocean is like the sea: unpredictable and you always run out of RAM)