Arabidopsis Roots and Shoots Show Distinct Temporal Adaptation Patterns toward Nitrogen Starvation

• Published in: Plant physiology (Bethesda) Vol. 157; no. 3; pp. 1255 - 1282
• Main Authors: Krapp, Anne, Berthomé, Richard, Orsel, Mathilde, Mercey-Boutet, Stéphanie, Yu, Agnes, Castaings, Loren, Elftieh, Samira, Major, Hilary, Renou, Jean-Pierre, Daniel-Vedele, Françoise
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.11.2011; Oxford University Press ; American Society of Plant Biologists
• Subjects: Adaptation, Physiological - drug effects; Agricultural sciences; Amino acids; Amino Acids - metabolism; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Biological Transport - drug effects; Biomass; Carbohydrate Metabolism - drug effects; Carboxylic Acids - metabolism; ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling; Gene expression regulation; Gene Expression Regulation, Plant - drug effects; Genes; Genes, Regulator - genetics; Life Sciences; Models, Biological; Nitrates; Nitrates - metabolism; Nitrogen; Nitrogen - deficiency; Nitrogen - metabolism; Nitrogen - pharmacology; Oligonucleotide Array Sequence Analysis; Plant physiology and development; Plant roots; Plant Roots - drug effects; Plant Roots - growth & development; Plant Roots - physiology; Plant Shoots - drug effects; Plant Shoots - enzymology; Plant Shoots - physiology; Plants; Proteins; Starvation; Statistics as Topic; Time Factors; Transcriptome - genetics; Transcriptomes; Arabidopsis thaliana; Root; Plant physiology; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Experimental plant; Nitrogen; Nutrient starvation; Shoot; Adaptation
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.111.179838

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.