Rice (Oryza sativa) leaf blades possess lobed mesophyll cells with intricate cell boundaries. Their sub-cellular structure has been observed with transmission electron microscopy (TEM) of thin sections, but the whole three-dimensional (3D) structure has not been reconstructed.
Oi et al. examine whole rice mesophyll cells using a Focus Ion Beam Scanning Electron Microscope (FIB-SEM). The 3-D reconstructed cell models were discoid-shaped, comprising several lobes around the cell periphery, with chloroplasts spread as sheets along the cell lobes and occupying half of the cell volume. The cell shape and chloroplast distribution enhances the leaf area available for CO2 absorption.