Anatomy of rice mesophyll cells and their chloroplasts based on the three-dimensional reconstruction method using FIB-SEM

Abstract

To observe internal structures, specimens need to be sliced into thin sections. Sectional images only provide two-dimensional (2D) data. However, the stacking of micrographs of serial sections provides three-dimensional (3D) volume data. In this review, we introduce the 3D reconstruction method using a focused ion beam scanning electron microscope (FIB-SEM) that provides multiple serial sections automatically and accurately. We examined rice leaves with FIB-SEM and reconstructed 3D models for whole mesophyll cells, revealing their intricate cell shape and intracellular distribution of chloroplasts. The 3D models enable us to quantitatively analyse volume and surface area, which are difficult to estimate based on 2D sections. This review emphasises the importance of the 3D anatomy that comprehensively captures the objects, compared to 2D observations of sections that are only parts of the object.