Abstract
The genesis of E. characias plant vacuoles was studied by high-voltage and conventional EM. Vacuole genesis is a lysosomal multistep process: GERL (Golgi-associated endoplasmic reticulum from which lysosomes apparently form) produces provacuoles into which lysosomal enzymes and other materials appear to be concentrated and packaged; GERL-derived provacuoles cooperate to drive a programmed cellular autophagy leading to young vacuoles and the young vacuoles swell and fuse together into a few large mature vacuoles which continue to collect the GERL-derived provacuoles throughout the life of the cell and in internal membrane flow.