#tracheophyta

Dr. Christine Strullu-Derrien and colleagues used the Canadian Light Source’s  Soft X-ray Spectromicroscopy beamline at the University of Saskatchewan to study Armoricaphyton chateaupannense, an extinct woody plant that is about 400 million years old. Their research focused on lignin, an organic compound in the plant tracheids, elongated cells that help transport water and mineral salts. Lignin makes the cells walls rigid and less water permeable, thereby improving the conductivity of their vascular system. [...] One of the challenges in this kind of study is that the fossilization process modifies soft plant tissue, which alters or obscures its original biochemical structure and makes it difficult to precisely reconstruct the original chemistry. This study, however, aided by advanced visualization technologies, identified lignified cells in the fossils, suggesting the plant contained decay-resistant lignin compounds. “Analyses show that both the 2D and 3D fossils have the same chemical composition, which is different than modern lignin, but the chemical signal of lignin is not completely lost in the fossilization process,” she said. Although the type of preservation of the plant fossils is not unique, “the combination of synchrotron methods used to study the structure and the chemistry of the wood at this level of detail is novel.”

Marsilea vestita, Hairy Waterclover Marsileaceae