title: Post-flowering nitrate uptake in wheat is controlled by N status at flowering, with a putative major role of root nitrate transporter NRT2.1.
abstract: In bread wheat (Triticum aestivum L.), the simultaneous improvement of both yield and grain protein is difficult because of the strong negative relationship between these two traits. However, some genotypes deviate positively from this relationship and this has been linked to their ability to take up nitrogen (N) during the post-flowering period, regardless of their N status at flowering. The physiological and genetic determinants of post-flowering N uptake relating to N satiety are poorly understood. This study uses semi-hydroponic culture of cv. Récital under controlled conditions to explore these controls. The first objective was to record the effects of contrasting N status at flowering on post-flowering nitrate (NO₃⁻) uptake under non-limiting NO₃⁻ conditions, while following the expression of key genes involved in NO₃⁻ uptake and assimilation. We found that post-flowering NO₃⁻ uptake was strongly influenced by plant N status at flowering during the first 300-400 degree-days after flowering, overlapping with a probable regulation of nitrate uptake exerted by N demand for growth. The uptake of NO₃⁻ correlated well with the expression of the gene TaNRT2.1, coding for a root NO₃⁻ transporter, which seems to play a major role in post-flowering NO₃⁻ uptake. These results provide a useful knowledge base for future investigation of genetic variability in post-flowering N uptake and may lead to concomitant gains in both grain yield and grain protein in wheat.
authors: INRA, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Clermont-Ferrand, France; Université Blaise Pascal, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Aubière, France; Arvalis-Institut du Végétal, Service Biotechnologies, Boigneville, France.
authors: François
authors: F
authors: Taulemesse
authors: INRA, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Clermont-Ferrand, France; Université Blaise Pascal, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Aubière, France.
authors: Jacques
authors: J
authors: Le Gouis
authors: Arvalis-Institut du Végétal, Service Biotechnologies, Boigneville, France.
authors: David
authors: D
authors: Gouache
authors: INRA, UMR 1332 Biologie du Fruit et Pathologie, Villenave d'Ornon, France.
authors: Yves
authors: Y
authors: Gibon
authors: INRA, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Clermont-Ferrand, France; Université Blaise Pascal, UMR 1095 Génétique Diversité et Ecophysiologie des Céréales, Aubière, France.
authors: Vincent
authors: V
authors: Allard
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D018533:Biomass; D035264:Flowers / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D000091285:Nitrate Transporters; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D027321:Anion Transport Proteins; D000091285:Nitrate Transporters; D009566:Nitrates; D010940:Plant Proteins; D009584:Nitrogen