Adjustment of growth and central metabolism to a mild but sustained nitrogen-limitation in Arabidopsis |
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Authors: | HENDRIK TSCHOEP YVES GIBON PETRONIA CARILLO PATRICK ARMENGAUD MAREK SZECOWKA ADRIANO NUNES-NESI ALISDAIR R FERNIE KARIN KOEHL & MARK STITT |
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Institution: | Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm, Germany,;Dipartimento di Scienze della Vita, Seconda Universita degli Studi di Napoli, Via Vivaldi 43, Caserta, Italy and;Plant Sciences Group, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK |
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Abstract: | We have established a simple soil-based experimental system that allows a small and sustained restriction of growth of Arabidopsis by low nitrogen (N). Plants were grown in a large volume of a peat–vermiculite mix that contained very low levels of inorganic N. As a control, inorganic N was added in solid form to the peat–vermiculite mix, or plants were grown in conventional nutrient-rich solids. The low N growth regime led to a sustained 20% decrease of the relative growth rate over a period of 2 weeks, resulting in a two- to threefold decrease in biomass in 35- to 40-day-old plants. Plants in the low N regime contained lower levels of nitrate, lower nitrate reductase activity, lower levels of malate, fumarate and other organic acids and slightly higher levels of starch, as expected from published studies of N-limited plants. However, their rosette protein content was unaltered, and total and many individual amino acid levels increased compared with N-replete plants. This metabolic phenotype reveals that Arabidopsis responds adaptively to low N by decreasing the rate of growth, while maintaining the overall protein content, and maintaining or even increasing the levels of many amino acids. |
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Keywords: | amino acids Arabidopsis enzymes nitrate nitrogen |
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