Plant vacuole lifecycle

The plant lytic vacuole, the largest compartment of most plant cells, is an acidic, hydrolase-filled organelle that also stores ions and metabolites and generates turgor. It grows from prevacuolar compartments and multivesicular bodies that fuse with the tonoplast, receives its hydrolases through sorting receptors, keeps its lumen acidic with the V-ATPase and the vacuolar pyrophosphatase, and in some cells is reorganized or dismantled, as in seed protein storage vacuoles and programmed cell death. This umbrella module composes the modules for those stages by reference. Intralumenal vesicle formation, hydrolase sorting, fusion with the tonoplast, acidification and tonoplast transport are required in the green lineage.

Organelle lifecycle umbrella (see projects/ORGANELLE_LIFECYCLES.md); stage roles and order slots follow the shared skeleton. Scoped to Viridiplantae because the fusion, sorting and tonoplast-transport rules are grounded in Arabidopsis; the ESCRT-III and V-ATPase rules are the eukaryote-wide ones that lysosome_lifecycle also requires. Read as a satisfiability rule, the umbrella is satisfied when all five referenced rules are. The sorting-receptor and tonoplast-transport rules are plant-only, like the fusion rule. Storage-vacuole biogenesis, vacuolar cell death and vacuole quality control are not modelled. The fusion part takes the skeleton's fusion slot (order 3), although the fusion modelled is mainly heterotypic delivery of prevacuolar compartments to the tonoplast rather than homotypic vacuole fusion. This umbrella overlaps lysosome_lifecycle, which covers lytic vacuoles eukaryote-wide and requires the same ESCRT-III and V-ATPase rules; it is kept separate because its fusion rule is grounded only in plant selectors, and it can fold into lysosome_lifecycle as a Viridiplantae variant once fungal and animal selectors exist.