Extracellular vesicles isolated from the apoplast of Arabidopsis leaves carry stress-response proteins
B. RUTTER (1), R. Innes (1) (1) Indiana University, U.S.A.

Exosomes are extracellular vesicles (EVs) that function in intercellular signaling in mammals by transporting proteins and small RNAs. Plants are also known to secrete exosomes, particularly in response to pathogen infection. However, the contents of plant exosomes have not been analyzed and their function is unknown. In order to better understand the role of plant exosomes, we developed a method for purifying EVs from the apoplastic fluid of Arabidopsis leaves. We isolated vesicles 20-200 nm in diameter that are associated with the syntaxin PENETRATION1 (PEN1) and the ABC transporter PENETRATION3 (PEN3), both of which are secreted in exosomes. Further proteomic analyses of the EVs revealed that they are highly enriched in proteins involved in biotic and abiotic stress responses. Consistent with this finding, EV secretion was enhanced in plants infected with a virulent strain of Pseudomonas syringae DC3000. Our analysis suggests that, similar to mammalian exosomes, plant exosomes play an integral role in the immune response and may mediate intracellular signaling through the transfer of proteins and miRNA.

Abstract Number: P18-690
Session Type: Poster