title: Plasmodesmata Localizing Proteins Regulate Transport and Signaling during Systemic Acquired Immunity in Plants.
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.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Gah-Hyun
authors.initials: GH
authors.lastname: Lim
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Shine
authors.affiliation: Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: de Lorenzo
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Keshun
authors.initials: K
authors.lastname: Yu
authors.affiliation: Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
authors.forename: Weier
authors.initials: W
authors.lastname: Cui
authors.affiliation: U.S. Department of Agriculture-Agricultural Research Service, Washington State University, Prosser, WA 99350, USA.
authors.forename: Duroy
authors.initials: D
authors.lastname: Navarre
authors.affiliation: Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Hunt
authors.affiliation: Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
authors.forename: Jung-Youn
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA. Electronic address: apkach2@uky.edu.
authors.forename: Aardra
authors.initials: A
authors.lastname: Kachroo
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA. Electronic address: pk62@uky.edu.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kachroo
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003998:Dicarboxylic Acids / Q000378:metabolism; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D005994:Glycerophosphates / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D031425:Plasmodesmata / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D044224:Pseudomonas syringae / Q000502:physiology; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: C539888:AZI1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D003998:Dicarboxylic Acids; D005994:Glycerophosphates; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C528450:PDLP1a protein, Arabidopsis; C586778:PDLP5 protein, Arabidopsis; C029620:alpha-glycerophosphoric acid; C010038:azelaic acid; D020156:Salicylic Acid