Dictyosome

A dictyosome is the plant and algal counterpart of the Golgi apparatus, a series of stacked, flattened membrane-bound cisternae that modify, sort, and package proteins and lipids for secretion or delivery to organelles. In many textbooks, the term dictyosome is used to emphasize the organelle’s role in processing secretory products in plant and algal cells.

Structurally, a dictyosome consists of multiple cisternae arranged in stacks and is typically dispersed throughout the cytoplasm, rather than being clustered near the nucleus as in some animal cells. Each stack has a cis face near the endoplasmic reticulum, a medial region, and a trans face from which vesicles bud off. The trans-Golgi network acts as a sorting hub, directing cargo to the plasma membrane, lysosome-like vacuoles, or the cell wall.

Functions include post-translational modification of proteins and lipids, such as glycosylation and sulfation, as well as the synthesis of polysaccharides destined for the cell wall, including pectin and hemicellulose. The dictyosome also participates in trafficking, generating vesicles that transport cargo to the plasma membrane or extracellular space and into vacuoles for storage or degradation.

In plants and many algae, the dictyosome is dynamically connected to the endomembrane system through vesicle exchange and shows variant organization across species. Although the term is still used, modern literature often uses Golgi apparatus or Golgi complex, with dictyosome specifically denoting the plant/algal context.