title: Arabidopsis roots and shoots show distinct temporal adaptation patterns toward nitrogen starvation.
abstract: Nitrogen (N) is an essential macronutrient for plants. N levels in soil vary widely, and plants have developed strategies to cope with N deficiency. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly understood. The aim of this study was to characterize N starvation in adult Arabidopsis (Arabidopsis thaliana) plants in a spatiotemporal manner by an integrative, multilevel global approach analyzing growth, metabolites, enzyme activities, and transcript levels. We determined that the remobilization of N and carbon compounds to the growing roots occurred long before the internal N stores became depleted. A global metabolite analysis by gas chromatography-mass spectrometry revealed organ-specific differences in the metabolic adaptation to complete N starvation, for example, for several tricarboxylic acid cycle intermediates, but also for carbohydrates, secondary products, and phosphate. The activities of central N metabolism enzymes and the capacity for nitrate uptake adapted to N starvation by favoring N remobilization and by increasing the high-affinity nitrate uptake capacity after long-term starvation. Changes in the transcriptome confirmed earlier studies and added a new dimension by revealing specific spatiotemporal patterns and several unknown N starvation-regulated genes, including new predicted small RNA genes. No global correlation between metabolites, enzyme activities, and transcripts was evident. However, this multilevel spatiotemporal global study revealed numerous new patterns of adaptation mechanisms to N starvation. In the context of a sustainable agriculture, this work will give new insight for the production of crops with increased N use efficiency.
authors: Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318 INRA-Agro-ParisTech, F-78026 Versailles cedex, France. anne.krapp@versailles.inra.fr
authors: Anne
authors: A
authors: Krapp
authors: Richard
authors: R
authors: Berthomé
authors: Mathilde
authors: M
authors: Orsel
authors: Stéphanie
authors: S
authors: Mercey-Boutet
authors: Agnes
authors: A
authors: Yu
authors: Loren
authors: L
authors: Castaings
authors: Samira
authors: S
authors: Elftieh
authors: Hilary
authors: H
authors: Major
authors: Jean-Pierre
authors: JP
authors: Renou
authors: Françoise
authors: F
authors: Daniel-Vedele
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002264:Carboxylic Acids / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005809:Genes, Regulator / Q000235:genetics; D008954:Models, Biological; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000172:deficiency* / Q000378:metabolism / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D018520:Plant Shoots / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D013223:Statistics as Topic; D013997:Time Factors; D059467:Transcriptome / Q000235:genetics
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D002264:Carboxylic Acids; D009566:Nitrates; D009584:Nitrogen