Direct acquisition of organic N by white clover even in the presence of inorganic N
- 698 Downloads
This study was conducted to answer the question of whether clover can absorb asparagine in the presence and absence of inorganic nitrogen, as well as to determine the resulting concentration of post-uptake compounds closely involved in asparagine metabolism.
Clover was grown at two asparagine concentrations (10 μM and 1 mM) supplied in both the absence and presence of ammonium nitrate. Using dual-labeled 13C15N-asparagine, the uptake rate was analyzed via bulk 15N and 13C excess and the detection of intact 13C15N-asparagine in white clover.
The results from the two methods indicated greater utilization of 13C15N-asparagine in the 10 μM treatment than in the 1 mM treatment. The 13C15N-asparagine uptake rate was higher when 13C15N-asparagine was provided alone than when it was supplemented with inorganic nitrogen. Up to nine times lower uptake rates were obtained when intact 13C15N-asparagine was measured than when bulk 15N and 13C excess were analyzed. The labeled amino acids that are closely related to 13C15N-asparagine metabolism (aspartic acid, glutamic acid and glutamine) were detected in clover roots and shoots.
Using two different methods, white clover’s potential to absorb intact asparagine, even in the presence of inorganic nitrogen, was confirmed. The dual-methodology approach employed in this study demonstrates how the post-uptake metabolism can affect quantification of amino acid uptake.
KeywordsAmino acids Inorganic nitrogen Uptake White clover Asparagine metabolism
This work was funded by Aarhus University in Denmark (project no. 15163). We gratefully acknowledge Annika Johansson and Thomas Moritz at the Swedish Metabolmics Centre for the use of the non-published amino acid analysis method. We also would like to acknowledge Andreas de Neergaard from the University of Copenhagen, Denmark for providing us with the hydroponic setup and assisting us with developing the conditions for plant growth.
Compliance with ethical standards
This work was funded by Aarhus University in Denmark (project no. 15,163).
Conflict of interest
The authors declare that they have no conflicts of interest.
- Armenta JM et al. (2010) Sensitive and rapid method for amino acid quantitation in malaria biological samples using AccQ.Tag Ultra Performance Liquid Chromatography-Electrospray Ionization-MS/MS with Multiple Reaction Monitoring. Anal Chem 82:548–558. doi: 10.1021/ac901790q CrossRefPubMedPubMedCentralGoogle Scholar
- Croghan C, Egeghy PP (2003) Methods of dealing with values below the limit of detection using SASGoogle Scholar
- Gold V, Loening KL, McNaught AD, Sehmi P (1987) In: V. KLL, Mcnaught AD, Sehmi P (eds) Compendium of chemical terminology IUPAC International Union of Pure And Applied Chemistry Recommendations Gold. . Compendium of Chemical Terminology, IupacGoogle Scholar
- Hogh-Jensen H, Schjoerring JK (2001) Rhizodeposition of nitrogen by red clover, white clover and ryegrass leys Soil Biol Biochem 33:439–448 doi: 10.1016/s0038-0717(00)00183-8
- Lesuffleur F, J-B C (2010a) Characterisation of root amino acid exudation in white clover. (Trifolium repens L) Plant Soil 333:191–201. doi: 10.1007/s11104-010-0334-1
- Lesuffleur F, J-B C (2010b) Characterisation of root amino acid exudation in white clover. (Trifolium repens L) Plant and Soil 333:191–201. doi: 10.1007/s11104-010-0334-1
- Louarn G, Pereira-Lopès E, Fustec J, Mary B, Voisin A-S, de Faccio CP, Gastal F (2014) The amounts and dynamics of nitrogen transfer to grasses differ in alfalfa and white clover-based grass-legume mixtures as a result of rooting strategies and rhizodeposit quality. Plant Soil. doi: 10.1007/s11104-014-2354-8 Google Scholar
- Macduff JH, Abberton MT, Raistrick N, Michaelson-Yeates ,TPT (2002) Low nitrate uptake white clover genotype - nitrogen relations of a low nitrate uptake inbred line of white clover. (Trifolium repens L) Plant and Soil 238:191–204. doi: 10.1023/a:1014456622446
- Pedersen HA, Kudsk P, Fiehn O, Fomsgaard IS (2013) The response of Arabidopsis to co-cultivation with clover investigating plant-plant interactions with metabolomics. In: Beck JJ, Coats JR, Duke SO, Koivunen ME (eds) Pest management with natural products, ACS Symposium Series, vol 1141. Amer Chemical Soc, Washington, pp. 189–201CrossRefGoogle Scholar