title: Dual regulation of root hydraulic conductivity and plasma membrane aquaporins by plant nitrate accumulation and high-affinity nitrate transporter NRT2.1.
abstract: The water status and mineral nutrition of plants critically determine their growth and development. Nitrate (NO3(-)), the primary nitrogen source of higher plants, is known to impact the water transport capacity of roots (root hydraulic conductivity, Lpr). To explore the effects and mode of action of NO3(-) on Lpr, we used an extended set of NO3(-) transport (nrt1.1, nrt1.2, nrt1.5 and nrt2.1), signaling (nrt1.1 and nrt2.1) and metabolism (nia) mutants in Arabidopsis, grown under various NO3(-) conditions. First, a strong positive relationship between Lpr and NO3(-) accumulation, in shoots rather than in roots, was revealed. Secondly, a specific 30% reduction of Lpr in nrt2.1 plants unraveled a major role for the high-affinity NO3(-) transporter NRT2.1 in increasing Lpr These results indicate that NO3(-)signaling rather than nitrogen assimilation products governs Lpr in Arabidopsis. Quantitative real-time reverse transcription-PCR and enzyme-linked immunosorbent assays (ELISAs) were used to investigate the effects of NO3(-) availability on plasma membrane aquaporin (plasma membrane intrinsic protein; PIP) expression. Whereas PIP regulation mostly occurs at the post-translational level in wild-type plants, a regulation of PIPs at both the transcriptional and translational levels was uncovered in nrt2.1 plants. In conclusion, this work reveals that control of Arabidopsis Lpr and PIP functions by NO3(-) involves novel shoot to root signaling and NRT2.1-dependent functions.
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche 5004, INRA/CNRS/Montpellier SupAgro/Université Montpellier, F-34060 Montpellier, Cedex 2, France Bio-Tech Research Center, Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan 250100, PR China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Li
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche 5004, INRA/CNRS/Montpellier SupAgro/Université Montpellier, F-34060 Montpellier, Cedex 2, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Tillard
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche 5004, INRA/CNRS/Montpellier SupAgro/Université Montpellier, F-34060 Montpellier, Cedex 2, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Gojon
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Unité Mixte de Recherche 5004, INRA/CNRS/Montpellier SupAgro/Université Montpellier, F-34060 Montpellier, Cedex 2, France maurel@supagro.inra.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Maurel
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000502:physiology*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000378:metabolism; D008565:Membrane Proteins
chemical_list: D027321:Anion Transport Proteins; D020346:Aquaporins; D029681:Arabidopsis Proteins; D009566:Nitrates; D010940:Plant Proteins; D014867:Water; C477335:NRT2.1 protein, Arabidopsis; C101492:NRT1.1 protein, Arabidopsis; C539716:NRT1.5 protein, Arabidopsis; C085550:At2g45960 protein, Arabidopsis; D008565:Membrane Proteins
keywords: Aquaporin; Arabidopsis thaliana; Nutrient; Root; Shoot to root signaling; Water transport