2024/09/21 by David Scheuring, Elena A. Minina, Falco Krueger +3 · 1 voice · 4 citations
Biochemistry, Genetics and Molecular Biology · #Cellular transport and secretion #Photosynthetic Processes and Mechanisms #Protist diversity and phylogeny
paper · doi:10.1093/plcell/koae243
openalex publication_date 2024/09/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/23
Plant vacuoles play key roles in cellular homeostasis, performing catabolic and storage functions, and regulating pH and ion balance. Despite their essential role, there is still no consensus on how vacuoles are established. A model proposing that the endoplasmic reticulum is the main contributor of membrane for growing vacuoles in meristematic cells has been challenged by a study proposing that plant vacuoles are formed de novo by homotypic fusion of multivesicular bodies (MVBs). Here, we use the Arabidopsis thaliana root as a model system to provide a systematic overview of successive vacuole biogenesis stages, starting from the youngest cells proximate to the quiescent center. We combine in vivo high- and super-resolution (STED) microscopy to demonstrate the presence of tubular and connected vacuolar structures in all meristematic cells. Using customized fluorescence recovery after photobleaching (FRAP) assays, we establish different modes of connectivity and demonstrate that thin, tubular vacuoles, as observed in cells near the quiescent center, form an interconnected network. Finally, we argue that a growing body of evidence indicates that vacuolar structures cannot originate from MVBs alone but receive membrane material from different sources simultaneously.