PT  - JOURNAL ARTICLE
AU  - Hannah M. McMillan
AU  - Sophia G. Zebell
AU  - Jean B. Ristaino
AU  - Xinnian Dong
AU  - Meta J. Kuehn
TI  - Protective Plant Immune Responses are Elicited by Bacterial Outer Membrane Vesicles
AID  - 10.1101/2020.07.24.220160
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.07.24.220160
4099  - http://biorxiv.org/content/early/2020/07/24/2020.07.24.220160.short
4100  - http://biorxiv.org/content/early/2020/07/24/2020.07.24.220160.full
AB  - Bacterial outer membrane vesicles (OMVs) perform a variety of functions in bacterial survival and virulence. In mammalian systems, OMVs activate immune responses and have been exploited as vaccines. However, little work has focused on the role that OMVs play during interactions with plant hosts. Here we report that OMVs from the pathogenic Pseudomonas syringae and the beneficial Pseudomonas fluorescens activate plant immune responses that protect against bacterial and oomycete pathogens. OMVs from these two species display different sensitivity to biochemical stressors, which could indicate differences in OMV cargo packaging. Furthermore, our study shows that OMV-induced protective immune responses are T3SS- and protein-independent, while OMV-mediated seedling growth inhibition largely depends on protein cargo. Importantly, OMV-mediated plant responses are distinct from those triggered by PAMP/MAMPs or effector molecules alone. OMVs provide a unique opportunity to study virulence factors in combination and add a new layer of interaction and complexity to host-microbe interactions.Competing Interest StatementThe authors have declared no competing interest.