Unveiling the impact of embedding resins on the physicochemical traits of wood cell walls with subcellular functional probing

As pressing needs for exploring molecular interactions in plants soar, conventional sample preparation methods come into question. Though resins used to embed plant tissues have long been assumed to bear no palpable effect on their properties, discrepancies in recent studies exploiting nanoscale microscopy suggest that their impact could be significant at small scales. By juxtaposing the traits of poplar sections prepared with and without embedding, we evaluate the diffusion (penetration depth) of acrylic and epoxy resins commonly used for embedding. Our results unveil critical quantitative differences when probing mechanical properties with a microscale nanoindentation indenter or a nanoscale tip. The latter resolves significant stiffness variations between the compound middle lamellae, the secondary cell wall layers S1 and S2, and the cell corner, not accessible with nanoindentation. Similar observations are drawn from comparing confocal Raman and nanoscale infrared spectroscopy. Our findings shed light on the effect of resin diffusion suggesting acrylic LR White to be the least diffusive for plant cell wall studies.

Automated summary

The study examines the impact of resin embedding on the mechanical properties of plant tissues at small scales through a comparison of prepared samples. Significant variations in stiffness are found between different layers of plant cell walls, with acrylic LR White identified as the least diffusive resin for exploring plant cell wall studies. The findings shed light on the importance of considering resin diffusion effects in molecular interaction studies in plants.