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Updated: Mar 28, 2026

Translating Ribosome Affinity Purification TRAP to Investigate Arabidopsis thaliana Root Development at a Cell Type-Specific Scale
Published on: May 14, 2020
Systemic Immunity Requires SnRK2.8-Mediated Nuclear Import of NPR1 in Arabidopsis
Hyo-Jun Lee1, Young-Joon Park1, Pil Joon Seo2
1Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
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.
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