Figure 1.

Schematic drawing of two types of ER-derived compartments in plant cells. Plant cells develop ER-derived compartments, which are classified into two types according to their contents: storage protein-type compartments (A) and hydrolytic enzyme-type compartments (B). PAC vesicles accumulate a large amount of storage protein precursors (solid triangles), while ER bodies accumulate a KDEL-tailed β-glycosidase, PYK10 (blue circles). Recycling receptors, vacuolar sorting receptor and KDEL receptor, are involved in the accumulation of the lumenal components in PAC vesicles and ER bodies, respectively. Open triangles, Mature form of storage proteins; open circles, ER resident proteins.