Nuclear localization of NPR1 is required for activation of PR gene expression.
Systemic acquired resistance (SAR) is a broad-spectrum resistance in plants that involves the upregulation of a battery of pathogenesis-related (PR) genes. NPR1 is a key regulator in the signal transduction pathway that leads to SAR. Mutations in NPR1 result in a failure to induce PR genes in systemic tissues and a heightened susceptibility to pathogen infection, whereas overexpression of the NPR1 protein leads to increased induction of the PR genes and enhanced disease resistance. We analyzed the subcellular localization of NPR1 to gain insight into the mechanism by which this protein regulates SAR. An NPR1-green fluorescent protein fusion protein, which functions the same as the endogenous NPR1 protein, was shown to accumulate in the nucleus in response to activators of SAR. To control the nuclear transport of NPR1, we made a fusion of NPR1 with the glucocorticoid receptor hormone binding domain. Using this steroid-inducible system, we clearly demonstrate that nuclear localization of NPR1 is essential for its activity in inducing PR genes.
Kinkema
M
M
Developmental, Cell, and Molecular Biology Group, Department of Biology, Duke University, Durham, North Carolina 27708-1000, USA.
Fan
W
W
Dong
X
X
D029681:Arabidopsis Proteins; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D017931:DNA Primers; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D019913:Nuclear Localization Signals; D010940:Plant Proteins / Q000235:genetics*; D011494:Protein Kinases; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
D029681:Arabidopsis Proteins; D017931:DNA Primers; D005656:Fungal Proteins; D008164:Luminescent Proteins; D019913:Nuclear Localization Signals; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C403250:proline-rich protein, Arabidopsis; D049452:Green Fluorescent Proteins; C066958:NPR1 protein, S cerevisiae; D011494:Protein Kinases