Fig. 5
From: Macro- and microscopic leaf injury triggered by ozone stress in beech foliage (Fagus sylvatica L.)
Contribution of plastoglobules to the accumulation of vacuolar lipids. a Accumulation of plastoglobules (in blue) in degenerating cells from palisade (PP) and spongy (SP) parenchyma. b Within stippling symptoms, lipids (encircled) were leaked into the enlarged intercellular spaces (is) between disrupted and cytorrhyzed cells (#). c Accumulation of large plastoglobules within chloroplasts (ch) from palisade parenchyma cells in leaves showing bronzing symptoms. d Accumulation of vacuolar lipid (lpv) after apparent excretion of plastoglobules into the vacuole. e–h Plastoglobule excretion and fate in the vacuole. e The plastoglobules excreted from chloroplasts into vacuoles (v) had their lipids apparently degraded, with an outer shrunken ring as the only remnant. f Accumulation of vacuolar lipids shortly before cell death within disrupting vacuoles (v ~). g Simultaneous accumulation of plastoglobules and condensed tannin (vct) in the vacuole, with lipids filling globular cavities within and gaps between tannin deposits. h Contiguous arrangement of lipids and tannins in the vacuole. The polymerization of condensed tannins in solid bodies was indicated by splits (arrows) and broken pieces (*). The vacuolar lipids formed globular deposits, sometimes encapsulated within tannin bodies and showing evidence of degradation. Other structures: c: cytoplasm; cw: cell wall; g: grana; LE: lower epidermis; n: nucleus; st: starch; UE: upper epidermis. Technical specifications: histochemical revelation of lipids using Sudan Black B (a–d), TEM as in Fig. 3 (e–h)