Spotlight on plant RNA-containing extracellular vesicles

Abstract

Extracellular vesicles (EVs) carrying RNA have attracted growing attention in plant cell biology. For a long time, EV release or uptake through the rigid plant cell wall was considered to be impossible and RNA outside cells to be unstable. Identified EV biomarkers have brought new insights into functional roles of EVs to transport their RNA cargo for systemic spread in plants and into plant-invading pathogens. RNA-binding proteins supposedly take over key functions in EV-mediated RNA secretion and transport, but the mechanisms of RNA sorting and EV translocation through the plant cell wall and plasma membrane are not understood. Characterizing the molecular players and the cellular mechanisms of plant RNA-containing EVs will create new knowledge in cell-to-cell and inter-organismal communication.

Keywords: Apoplast wash fluid; Biomarker; Cell-wall remodeling; EXPO; Extracellular RNA; Extracellular vesicle; MVB; Papillary matrix; Plant defense; Polysome; Post-transcriptional modification; RNA communication; RNA loading; RNA secretion; RNA sorting; RNA-Binding protein; Syntaxin; Tetraspanin; ckRNAi.