UvA

All plant cells contain numerous organelles, like mitochondria chloroplasts, with specific functions that are generally very similar among cell types and species. However, vacuoles, which are by far the largest compartments in plant cells, show a broad diversification in shape, dimensions, content and function among species and tissues. Plant vacuoles are essential in plant development as they maintain turgor pressure and cell shape thereby participating to build the plant structure. Vacuoles are also for protein storage, cytosolic ion homoeostasis and sequestration of secondary metabolites and toxic compounds. Some specialized plant cells contain multiple vacuoles with different functions. The distinct vacuolar functions are mirrored by the large variety of proteins that reside in this organelle. In particular, a multitude of transporters on the tonoplast define the traffic of molecules to and from the cytoplasm, resulting in distinct compositions of the vacuolar lumen. These transporters are therefore major contributors in defining the identity and function of the different vacuolar types. In this thesis the study of different aspects of plant vacuoles biogenesis, functions and dynamics were studied by combining molecular genetic strategies, such as the analysis of mutants and transcriptomes, with evolutionary analyses comparing distinct plant species with specific adaptations.