|LIM, GAH-HYUN - University Of Kentucky|
|SHINE, M - University Of Kentucky|
|DE LORENZO, LAURA - University Of Kentucky|
|YU, KESHUN - University Of Kentucky|
|WEIER, CUI - University Of Delaware|
|Navarre, Duroy - Roy|
|HUNT, ARTHUR - University Of Kentucky|
|LEE, JUNG-YOUN - University Of Delaware|
|KACHROO, AARDRA - University Of Kentucky|
|KACHROO, PRADEEP - University Of Kentucky|
Submitted to: Cell Host and Microbe
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2016
Publication Date: 4/13/2016
Citation: Lim, G., Shine, M.B., De Lorenzo, L., Yu, K., Weier, C., Navarre, D.A., Hunt, A.G., Lee, J., Kachroo, A., Kachroo, P. 2016. Plasmodesmata localizing proteins regulate transport and signaling during systemic acquired immunity in plants. Cell Host and Microbe. 19:541-549.
Interpretive Summary: A lack of effective disease resistance in plants reduces yield and quality and necessitates costly pesticide usage. Scientists at the University of Kentucky, University of Delaware and the USDA-ARS in Prosser, Washington showed that plant plasmodesmata have a key role in transporting chemical signals needed for plant defense. Proteins that localize to the plasmodesmata were shown to regulate permeability of plasmodesmata, transport of defense signals and the stability and localization of plant defense proteins. These results reveal new mechanisms that plants use to resist disease and can enable the production of crops with superior disease resistance.
Technical Abstract: Systemic acquired resistance (SAR) in plants is mediated by the signaling molecules azelaic acid (AzA),glycerol-3-phosphate (G3P), and salicylic acid (SA).Here, we show that AzA and G3P transport occurs via the symplastic route, which is regulated by channels known as plasmodesmata (PD). In contrast, SA moves via the extracytosolic apoplast compartment. We found that PD localizing proteins (PDLP) 1 and 5 were required for SAR even though PD permeability in pdlp1 and 5 mutants was comparable to or higher than wild-type plants, respectively. Furthermore, PDLP function was required in the recipient cell, suggesting regulatory function in SAR. Interestingly, overexpression of PDLP5 drastically reduced PD permeability, yet also impaired SAR. PDLP1 interacted with AZI1 (lipid transfer-like protein required for AzA- and G3P-induced SAR) and contributed to its intracellular partitioning. Together, these results reveal the transport routes of SAR chemical signals and highlight the regulatory role of PD-localizing proteins in SAR.