Annual Plant Reviews, Volume 9 The Golgi apparatus is at the fulcrum of secretory traffic, beginning at the endoplasmic reticulum and culminating at the cell surface or lytic/vacuolar compartments. Its major functions are protein glycosylation and polysaccharide synthesis, on one hand, and protein sorting on the other. With advances in our understanding of how the Golgi apparatus operates in plants, the possibility of manipulating the timing, type and site of delivery of secretory macromolecules is therefore becoming more and more feasible. This will be important not only for improving crop production, but also for increasing the use of plants as bioreactors for vaccines and other therapeutic agents. This volume concentrates on the major developments of the last few years, drawing attention to the distinct differences between the plant and non-plant Golgi apparatus and highlighting unsolved problems. A chapter is included on the yeast Golgi apparatus. This is a volume for researchers and professionals in plant cell biology, biochemistry, physiology and molecular biology.