Membrane vesicle (MV) release occurs in all forms of life, including Gram-negative and Gram-positive bacteria. Bacterial MVs have been studied mostly in relation to the bacterial lifestyle and regarding their role during mammalian host interactions. Surprisingly, while plants are known to be colonized by pathogenic, mutualistic, and commensal bacteria, the functions of MVs produced by these plant colonizers have only begun to be studied in the past decade. In fact, only a handful of studies have been published on this topic. Nevertheless, it is apparent that this field is gaining increasing attention, as does the role of plant and fungal extracellular vesicles (EVs) during plant–pathogen interactions. In this chapter I will review the current literature on plant-associated bacterial MVs and their interactions with plants. I will focus on MV cargo with emphasis on virulence-related proteins and on MVs’ function during host colonization including interactions with the plant immune system. I will further provide a view of the possible, yet unexplored, roles of MVs in plant–bacteria interactions, and highlight important questions and limitations in the study of MVs.
Membrane vesicle (MV) release occurs in all forms of life, including Gram-negative and Gram-positive bacteria. Bacterial MVs have been studied mostly in relation to the bacterial lifestyle and regarding their role during mammalian host interactions. Surprisingly, while plants are known to be colonized by pathogenic, mutualistic, and commensal bacteria, the functions of MVs produced by these plant colonizers have only begun to be studied in the past decade. In fact, only a handful of studies have been published on this topic. Nevertheless, it is apparent that this field is gaining increasing attention, as does the role of plant and fungal extracellular vesicles (EVs) during plant–pathogen interactions. In this chapter I will review the current literature on plant-associated bacterial MVs and their interactions with plants. I will focus on MV cargo with emphasis on virulence-related proteins and on MVs’ function during host colonization including interactions with the plant immune system. I will further provide a view of the possible, yet unexplored, roles of MVs in plant–bacteria interactions, and highlight important questions and limitations in the study of MVs.