Fig. 3.

Starch accumulation after brefeldin A treatment in Arabidopsis thaliana roots (A–D, scale bars=500 nm) and cotyledonary leaves (E–K, scale bars E–F=100 nm; G–L=500 nm). (A and B) Root meristem plastids may be starch free or contain only small starch grains. (C and D) At 2 h after treatment nearly all plastids are showing large starch granules. (E) Golgi in untreated cotyledons with an approximate size of 600–800 nm. (F) Golgi bodies are still present after 2 h BFA treatment but are much smaller (∼300 nm in diameter) than control Golgi bodies. (G and H) Untreated cotyledonary leaves showing similar patterns to roots. Plastids with and without starch grains are present. (I) After 3 h of BFA (50 μg ml⁻¹) treatment most of the plastids show starch granules. (J) After 4 h in BFA nearly all plastids within a cell show large starch granules. (K) A leaf treated for 5 h with starch granules within the interthylakoidal spaces. (L) Chloroplasts 6 h after adding BFA.