title: Systemic Immunity Requires SnRK2.8-Mediated Nuclear Import of NPR1 in Arabidopsis.
abstract: In plants, necrotic lesions occur at the site of pathogen infection through the hypersensitive response, which is followed by induction of systemic acquired resistance (SAR) in distal tissues. Salicylic acid (SA) induces SAR by activating NONEXPRESSER OF PATHOGENESIS-RELATED GENES1 (NPR1) through an oligomer-to-monomer reaction. However, SA biosynthesis is elevated only slightly in distal tissues during SAR, implying that SA-mediated induction of SAR requires additional factors. Here, we demonstrated that SA-independent systemic signals induce a gene encoding SNF1-RELATED PROTEIN KINASE 2.8 (SnRK2.8), which phosphorylates NPR1 during SAR. The SnRK2.8-mediated phosphorylation of NPR1 is necessary for its nuclear import. Notably, although SnRK2.8 transcription and SnRK2.8 activation are independent of SA signaling, the SnRK2.8-mediated induction of SAR requires SA. Together with the SA-mediated monomerization of NPR1, these observations indicate that SA signals and SnRK2.8-mediated phosphorylation coordinately function to activate NPR1 via a dual-step process in developing systemic immunity in Arabidopsis thaliana.
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors.forename: Hyo-Jun
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Department of Chemistry, Chonbuk National University, Jeonju 561-756, Korea.
authors.forename: Pil Joon
authors.initials: PJ
authors.lastname: Seo
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors.forename: Ju-Heon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Center for Genome Engineering, Institute for Basic Science, Daejeon 305-811, Korea.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Sim
authors.affiliation: Center for Genome Engineering, Institute for Basic Science, Daejeon 305-811, Korea.
authors.forename: Sang-Gyu
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Korea Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Korea cmpark@snu.ac.kr.
authors.forename: Chung-Mo
authors.identifier: http://orcid.org/0000-0001-8841-8361
authors.initials: CM
authors.lastname: Park
mesh_terms: D021581:Active Transport, Cell Nucleus; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D010766:Phosphorylation; D057865:Plant Immunity; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; C105496:NPR1 protein, Arabidopsis; C492978:SnRK2 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D020156:Salicylic Acid