Mitochondria: Key Organelles Accelerating Cell Wall Material Accumulation in Juice Sacs of Pummelo (Citrus grandis L. Osbeck) Fruits during Postharvest Storage

Figure 5

Transmission electron micrographs of cross sections of dorsal juice sac (a–c) and septal juice sac (d–f) of pummelo fruit stored for 40 days at room temperature. (a) Overview of the cell structure of a dorsal juice sac. (b, c) Higher magnification micrographs of the regions marked by rectangles in (a). Note the concurrent increases in the abundance of mitochondria and cell wall materials. (d) Overview of the cell structure of a septal juice sac. (e, f) Higher magnification micrographs of the regions marked by rectangles in (d). Note long microfibrils in the intracellular spaces and secondary cell wall thickening. Cw: cell wall, M: mitochondrion, V: vesicle, Is: intercellular space, open arrow: plasma membrane, white arrowhead: microfibril, and black arrowhead: cell wall materials.

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