This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Bloom, A. J. Articles by Sukrapanna, S. S. Search for Related Content PubMed PubMed Citation Articles by Bloom, A. J. Articles by Sukrapanna, S. S. Agricola Articles by Bloom, A. J. Articles by Sukrapanna, S. S.

Environmental and Stress Physiology

Effects of Exposure to Ammonium and Transplant Shock upon the Induction of Nitrate Absorption ¹

Department of Vegetable Crops, University of California, Davis, California 95616

In barley (Hordeum vulgare L. cv Steptoe) seedlings, the time course for induction of root nitrate absorption varied significantly with pretreatment. Net nitrate uptake of nitrogen-deprived plants more than doubled during the 12 hours after first exposure to nitrate. For these plants, gentle physical disturbance of the roots inhibited net nitrate absorption for more than 6 hours and potassium absorption for 2 hours. Pretreatment with ammonium appeared sufficient to induce nitrate absorption; plants either grown for 2 weeks on or exposed for only 10 hours to a medium containing ammonium as a sole nitrogen source showed high rates of net nitrate uptake when first shifted to a medium containing nitrate. Gentle physical manipulation of these plants inhibited nitrate absorption for 2 hours and potassium absorption for more than 12 hours. These results indicate (a) that experimental protocols should avoid physical manipulation of the roots when-ever possible and (b) that ammonium or a product of ammonium assimilation can induce nitrate absorption.

This article has been cited by other articles:

				P. Merigout, M. Lelandais, F. Bitton, J.-P. Renou, X. Briand, C. Meyer, and F. Daniel-Vedele Physiological and Transcriptomic Aspects of Urea Uptake and Assimilation in Arabidopsis Plants Plant Physiology, July 1, 2008; 147(3): 1225 - 1238. [Abstract] [Full Text] [PDF]

				A. J. BLOOM, J. FRENSCH, and A. R. TAYLOR Influence of Inorganic Nitrogen and pH on the Elongation of Maize Seminal Roots Ann. Bot., May 1, 2006; 97(5): 867 - 873. [Abstract] [Full Text] [PDF]

				D. T. Britto, M. W. Szczerba, and H. J. Kronzucker A new, non-perturbing, sampling procedure in tracer exchange measurements J. Exp. Bot., March 1, 2006; 57(6): 1309 - 1314. [Abstract] [Full Text] [PDF]

				J. H. Macduff and A. K. Bakken Diurnal variation in uptake and xylem contents of inorganic and assimilated N under continuous and interrupted N supply to Phleum pratense and Festuca pratensis J. Exp. Bot., January 2, 2003; 54(381): 431 - 444. [Abstract] [Full Text] [PDF]

				J. H. MACDUFF, M. O. HUMPHREYS, and H. THOMAS Effects of a Stay-green Mutation on Plant Nitrogen Relations in Lolium perenne During N Starvation and after Defoliation Ann. Bot., January 1, 2002; 89(1): 11 - 21. [Abstract] [Full Text] [PDF]

				P. Pouliquin, J.-C. Boyer, J.-P. Grouzis, and R. Gibrat Passive Nitrate Transport by Root Plasma Membrane Vesicles Exhibits an Acidic Optimal pH Like the H+-ATPase Plant Physiology, January 1, 2000; 122(1): 265 - 274. [Abstract] [Full Text] [PDF]