Fig. 5.

Electron micrographs of Zygnema sp. G control cells (a–c) and cells treated for 3 h with 800 mM sorbitol (d–e). (a) overview of a pre-akinete cell that still shows vacuolization, nucleus, chloroplast and pyrenoids are clearly visible, (b) cell centre with mitochondria and ER, (c) golgi body, (d) cell centre with nucleus and partially disrupted mitochondria (arrows), (e) chloroplast with massive plastoglobules, golgi bodies with reduced cisternae. Abbreviations: Chl, chloroplast, CW, cell wall, ER, endoplasmic reticulum, G, golgi body, M, mitochondrion, N, nucleus, PG, plastoglobule, Py, pyrenoid, V, vacuole. Bars a 10 μm, b and c 1 μm, d and e 500 nm.