Growing pains: addressing the pitfalls of plant extracellular vesicle research

Extracellular vesicles (EVs) are small, membrane-enclosed compartments that mediate the intercellular transport of proteins and small RNAs. In plants, EVs are thought to play a prominent role in immune responses and are being championed as the long-sought-after mechanism for host-induced gene silencing. However, parallel research on mammalian EVs is raising concerns about potential pitfalls faced by all EV researchers that will need to be addressed in order to convincingly establish that EVs are the primary mediators of small RNA transfer between organisms. Here we discuss these pitfalls in the context of plant EV research, with a focus on experimental approaches required to distinguish bona fide EV cargo from merely co-purifying contaminants.