Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

Potential organic and inorganic N uptake by six Eucalyptus species

C. R. Warren

School of Forest and Ecosystem Science, The University of Melbourne, Water Street, Creswick, Vic. 3363, Australia. Email: crwarren@unimelb.edu.au

Functional Plant Biology 33(7) 653-660 http://dx.doi.org/10.1071/FP06045
Submitted: 6 March 2006  Accepted: 28 April 2006   Published: 3 July 2006

Abstract

There are no published studies of organic N uptake by species of south-eastern Australia (e.g. Eucalyptus) despite several studies of ecosystem N cycling. This study examines uptake of nitrate, ammonium and glycine (an amino acid) by six species of 16-year-old Eucalyptus growing at two plantations (‘common gardens’). By using two plantations, one xeric / oligotrophic and one mesic / eutrophic, I was able to disentangle genotypic from phenotypic differences in preference for N forms. Measurements were made on three separate occasions during spring. N uptake was examined in situ with attached roots placed in uptake solutions containing equimolar 100 μmol L–1 concentrations of 15N-nitrate, 15N-ammonium and 2-13C215N-glycine. Water and KCl extracts were used to determine the relative abundances of nitrate, ammonium and amino acids at the two plantations. Nitrate dominated at the eutrophic site, but was nearly absent at the oligotrophic site. N at the oligotrophic site was dominated by ammonium and amino acids which were present in similar concentrations. The rate of uptake of ammonium (6.3 ± 0.4 μmol g h–1; mean ± s.e., n = 108), was faster than glycine (3.4 ± 0.2), which was faster than nitrate (0.62 ± 0.07). Plant ‘preference’ for N forms did not vary between sites despite large differences in the relative abundances of N forms (nitrate v. ammonium v. amino acids). Hence, there was little evidence for acclimation of Eucalyptus species to differences in the relative availability of N forms. This study suggests the possibility for considerable organic N uptake in the field. Previous studies of ecosystem N cycling in south-eastern Australia have only examined inorganic N. The N cycle in south-eastern Australia needs to be revisited with a new perspective, one that considers inorganic N and organic N.

Keywords: amino acid, ammonium, common garden, Eucalyptus, glycine, nitrate, nitrogen, organic N, plantation, uptake.


References

Adams MA Attiwill PM 1982 Nitrate reductase-activity and growth-response of forest species to ammonium and nitrate sources of nitrogen. Plant and Soil 66 373 381 doi:10.1007/BF02183803

Attiwill PM Adams MA 1993 Nutrient cycling in forests. New Phytologist 124 561 582 doi:10.1111/j.1469-8137.1993.tb03847.x

Attiwill PM , Polglase PJ , Weston CJ , Adams MA (1996) Nutrient cycling in forests of south-eastern Australia. In ‘Nutrition of eucalypts’. (Eds PM Attiwill, MA Adams) pp. 191–228. (CSIRO Publishing: Melbourne)

Brooker MIH 2000 A new classification of the genus Eucalyptus L’Her. (Myrtaceae). Australian Systematic Botany 13 79 148 doi:10.1071/SB98008

Chapin FS Moilanen L Kielland K 1993 Preferential use of organic nitrogen for growth by a nonmycorrhizal arctic sedge. Nature 361 150 153 doi:10.1038/361150a0

Duncan MJ , Baker TG , Appleton R , Stokes RC (2000) ‘Growth of eucalypt plantation species across twelve sites in Gippsland Victoria.’ (Department of Natural Resources and Environment: Melbourne)

Garnett TP Shabala SN Smethurst PJ Newman IA 2003 Kinetics of ammonium and nitrate uptake by eucalypt roots and associated proton fluxes measured using ion selective microelectrodes. Functional Plant Biology 30 1165 1176 doi:10.1071/FP03087

Giblin AE Laundre JA Nadelhoffer KJ Shaver GR 1994 Measuring nutrient availability in arctic soils using ion-exchange resins — a field-test. Soil Science Society of America Journal 58 1154 1162

Hodge A Robinson D Fitter A 2000 Are microorganisms more effective than plants at competing for nitrogen? Trends in Plant Science 5 304 308 doi:10.1016/S1360-1385(00)01656-3

Jones DL Owen AG Farrar JF 2002 Simple method to enable the high resolution determination of total free amino acids in soil solutions and soil extracts. Soil Biology and Biochemistry 34 1893 1902 doi:10.1016/S0038-0717(02)00203-1

Jones DL Healey JR Willett VB Farrar JF Hodge A 2005 Dissolved organic nitrogen uptake by plants — an important N uptake pathway? Soil Biology and Biochemistry 37 413 423 doi:10.1016/j.soilbio.2004.08.008

Kaye JP Hart SC 1997 Competition for nitrogen between plants and soil microorganisms. Trends in Ecology and Evolution 12 139 143 doi:10.1016/S0169-5347(97)01001-X

Kronzucker HJ Siddiqi MY Glass ADM 1997 Conifer root discrimination against soil nitrate and the ecology of forest succession. Nature 385 59 61 doi:10.1038/385059a0

McKane RB Johnson LC Shaver GR Nadelhoffer KJ Rastetter EB et al 2002 Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra. Nature 415 68 71 doi:10.1038/415068a

Miller AE Bowman WD 2002 Variation in nitrogen-15 natural abundance and nitrogen uptake traits among co-occurring alpine species: do species partition by nitrogen form? Oecologia 130 609 616 doi:10.1007/s00442-001-0838-8

Miller AE Bowman WD 2003 Alpine plants show species-level differences in the uptake of organic and inorganic nitrogen. Plant and Soil 250 283 292 doi:10.1023/A:1022867103109

Moore S 1968 Amino acid analysis: aqueous dimethyl sulphoxide as solvent for the ninhydrin reaction. Journal of Biological Chemistry 243 6281 6283

Murphy J Riley JP 1962 A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta 27 31 36 doi:10.1016/S0003-2670(00)88444-5

Näsholm T Persson J 2001 Plant acquisition of organic nitrogen in boreal forests. Physiologia Plantarum 111 419 426 doi:10.1034/j.1399-3054.2001.1110401.x

Näsholm T Huss-Danell K Hogberg P 2000 Uptake of organic nitrogen in the field by four agriculturally important plant species. Ecology 81 1155 1161 doi:10.2307/177188

Persson J Näsholm T 2001 Amino acid uptake: a widespread ability among boreal forest plants. Ecology Letters 4 434 438 doi:10.1046/j.1461-0248.2001.00260.x

Persson J Hogberg P Ekblad A Hogberg MN Nordgren A Näsholm T 2003 Nitrogen acquisition from inorganic and organic sources by boreal forest plants in the field. Oecologia 137 252 257 doi:10.1007/s00442-003-1334-0

Raven JA Farquhar GD 1990 The influence of N-metabolism and organic-acid synthesis on the natural abundance of isotopes of carbon in plants. New Phytologist 116 505 529 doi:10.1111/j.1469-8137.1990.tb00536.x

Schmidt S Stewart GR 1999 Glycine metabolism by plant roots and its occurrence in Australian plant communities. Australian Journal of Plant Physiology 26 253 264

Skogley EO Dobermann A 1996 Synthetic ion-exchange resins: Soil and environmental studies. Journal of Environmental Quality 25 13 24

Stewart GR Pearson J Kershaw JL Clough ECM 1989 Biochemical aspects of inorganic nitrogen assimilation by woody-plants. Annales Des Sciences Forestieres 46 S648 S653

Turnbull MH Goodall R Stewart GR 1995 The impact of mycorrhizal colonization upon nitrogen source utilization and metabolism in seedlings of Eucalyptus grandis Hill ex Maiden and Eucalyptus maculata Hook. Plant, Cell and Environment 18 1386 1394 doi:10.1111/j.1365-3040.1995.tb00199.x

Turnbull MH Schmidt S Erskine PD Richards S Stewart GR 1996 Root adaptation and nitrogen source acquisition in natural ecosystems. Tree Physiology 16 941 948

Warren CR Adams MA 2002 Possible causes of slow growth of nitrate-supplied Pinus pinaster. Canadian Journal of Forest Research 32 569 580 doi:10.1139/x01-225

Warren CR Adams MA 2004 Capillary electrophoresis of the major anions and cations in leaf extracts of woody species. Phytochemical Analysis 15 407 413 doi:10.1002/pca.801

Weigelt A King R Bol R Bardgett RD 2003 Inter-specific variability in organic nitrogen uptake of three temperate grassland species. Journal of Plant Nutrition and Soil Science-Zeitschrift Fur Pflanzenernahrung Und Bodenkunde 166 606 611 doi:10.1002/jpln.200320322

Weigelt A Bol R Bardgett RD 2005 Preferential uptake of soil nitrogen forms by grassland plant species. Oecologia 142 627 635 doi:10.1007/s00442-004-1765-2

Wright DE 1962 Amino acid uptake by plant roots. Archives of Biochemistry and Biophysics 97 174 180 doi:10.1016/0003-9861(62)90061-9



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