title: The Calcium Ion Is a Second Messenger in the Nitrate Signaling Pathway of Arabidopsis.
abstract: Understanding how plants sense and respond to changes in nitrogen availability is the first step toward developing strategies for biotechnological applications, such as improvement of nitrogen use efficiency. However, components involved in nitrogen signaling pathways remain poorly characterized. Calcium is a second messenger in signal transduction pathways in plants, and it has been indirectly implicated in nitrate responses. Using aequorin reporter plants, we show that nitrate treatments transiently increase cytoplasmic Ca(2+) concentration. We found that nitrate also induces cytoplasmic concentration of inositol 1,4,5-trisphosphate. Increases in inositol 1,4,5-trisphosphate and cytoplasmic Ca(2+) levels in response to nitrate treatments were blocked by U73122, a pharmacological inhibitor of phospholipase C, but not by the nonfunctional phospholipase C inhibitor analog U73343. In addition, increase in cytoplasmic Ca(2+) levels in response to nitrate treatments was abolished in mutants of the nitrate transceptor NITRATE TRANSPORTER1.1/Arabidopsis (Arabidopsis thaliana) NITRATE TRANSPORTER1 PEPTIDE TRANSPORTER FAMILY6.3. Gene expression of nitrate-responsive genes was severely affected by pretreatments with Ca(2+) channel blockers or phospholipase C inhibitors. These results indicate that Ca(2+) acts as a second messenger in the nitrate signaling pathway of Arabidopsis. Our results suggest a model where NRT1.1/AtNPF6.3 and a phospholipase C activity mediate the increase of Ca(2+) in response to nitrate required for changes in expression of prototypical nitrate-responsive genes.
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.).
authors: Eleodoro
authors: E
authors: Riveras
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.).
authors: José M
authors: JM
authors: Alvarez
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.).
authors: Elena A
authors: http://orcid.org/0000-0002-8208-7327
authors: EA
authors: Vidal
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.).
authors: Carolina
authors: C
authors: Oses
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.).
authors: Andrea
authors: A
authors: Vega
authors: Fondo de Desarrollo de Areas Prioritarias Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile 8331010 (E.R., J.M.A., E.A.V., C.O., A.V., R.A.G.); andFacultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago, Chile 7820436 (A.V.) rgutierrez@bio.puc.cl.
authors: Rodrigo A
authors: RA
authors: Gutiérrez
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism* / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D027321:Anion Transport Proteins; C101492:NRT1.1 protein, Arabidopsis; D009566:Nitrates; D010716:Phosphatidylinositols; D010940:Plant Proteins; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D002118:Calcium