Figure 4.

Effect of inhibitors or intermediates of the tetrapyrrole biosynthesis pathway on starch accumulation. A, Schematic diagram of the tetrapyrrole biosynthesis pathway. Specific inhibitors and intermediates used in this study are indicated in boldface. Intermediates were as follows: Glu, ALA, proto IX, Mg-proto IX, and chlorophyll a and chlorophyll b (Chl a and Chl b). B to H, Staining of starch granules in plastids. BY-2 cells were grown for 96 h in F medium in the absence (B) or presence of 500 μm LA (C) or in B medium in the absence (D) or presence of 100 μm ALA (E), 40 μm proto IX (F), 10 μm Mg-proto IX (G), or 40 μm heme (H) and stained with iodine solution. Bars = 20 μm.