Fig. 6
From: Macro- and microscopic leaf injury triggered by ozone stress in beech foliage (Fagus sylvatica L.)
Cellular and subcellular changes caused by oxidative stress in the upper epidermis (a–d), spongy parenchyma (e–h) and lower epidermis (i–j) of symptomatic (c, d, g, h, j) versus asymptomatic (a, b, e, f, i) foliage material. Degenerative changes were indicated by the condensation of cytoplasm (c), decrease of thylakoids and increase of plastoglobules within leucoplasts (lc) or chloroplasts (ch), injury (+) to cristae and matrix of mitochondria (mt) and accumulation of condensed tannins (vct) in the vacuole (v). Notice the lower physiological activity in the asymptomatic epidermis (a, b, i) versus spongy parenchyma (e, f), as indicated by the thinner cytoplasm layer, few organelles, larger vacuome and more condensed nucleus structure (n). Other structures: cu: cuticle; cw: cell wall; g: grana; is: intercellular space; re: smooth endoplasmic reticulum, st: starch, v: vacuole. Technical specifications: TEM as in Fig. 3