Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat.
Nitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH(4)(+) and NO(3)(-)) and L-amino acids have been considered to be important to the N nutrition of terrestrial plants. However, amino acids are also present in soil as small peptides...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2011-04-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3082556?pdf=render |
| _version_ | 1828422500162207744 |
|---|---|
| author | Paul W Hill Richard S Quilliam Thomas H DeLuca John Farrar Mark Farrell Paula Roberts Kevin K Newsham David W Hopkins Richard D Bardgett David L Jones |
| author_facet | Paul W Hill Richard S Quilliam Thomas H DeLuca John Farrar Mark Farrell Paula Roberts Kevin K Newsham David W Hopkins Richard D Bardgett David L Jones |
| author_sort | Paul W Hill |
| collection | DOAJ |
| description | Nitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH(4)(+) and NO(3)(-)) and L-amino acids have been considered to be important to the N nutrition of terrestrial plants. However, amino acids are also present in soil as small peptides and in D-enantiomeric form. We compared the uptake and assimilation of N as free amino acid and short homopeptide in both L- and D-enantiomeric forms. Sterile roots of wheat (Triticum aestivum L.) plants were exposed to solutions containing either (14)C-labelled L-alanine, D-alanine, L-trialanine or D-trialanine at a concentration likely to be found in soil solution (10 µM). Over 5 h, plants took up L-alanine, D-alanine and L-trialanine at rates of 0.9±0.3, 0.3±0.06 and 0.3±0.04 µmol g(-1) root DW h(-1), respectively. The rate of N uptake as L-trialanine was the same as that as L-alanine. Plants lost ca.60% of amino acid C taken up in respiration, regardless of the enantiomeric form, but more (ca.80%) of the L-trialanine C than amino acid C was respired. When supplied in solutions of mixed N form, N uptake as D-alanine was ca.5-fold faster than as NO(3)(-), but slower than as L-alanine, L-trialanine and NH(4)(+). Plants showed a limited capacity to take up D-trialanine (0.04±0.03 µmol g(-1) root DW h(-1)), but did not appear to be able to metabolise it. We conclude that wheat is able to utilise L-peptide and D-amino acid N at rates comparable to those of N forms of acknowledged importance, namely L-amino acids and inorganic N. This is true even when solutes are supplied at realistic soil concentrations and when other forms of N are available. We suggest that it may be necessary to reconsider which forms of soil N are important in the terrestrial N cycle. |
| first_indexed | 2024-12-10T15:48:11Z |
| format | Article |
| id | doaj.art-d7a9a6700ec243a89412019653e132e6 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T15:48:11Z |
| publishDate | 2011-04-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-d7a9a6700ec243a89412019653e132e62022-12-22T01:42:54ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-04-0164e1922010.1371/journal.pone.0019220Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat.Paul W HillRichard S QuilliamThomas H DeLucaJohn FarrarMark FarrellPaula RobertsKevin K NewshamDavid W HopkinsRichard D BardgettDavid L JonesNitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH(4)(+) and NO(3)(-)) and L-amino acids have been considered to be important to the N nutrition of terrestrial plants. However, amino acids are also present in soil as small peptides and in D-enantiomeric form. We compared the uptake and assimilation of N as free amino acid and short homopeptide in both L- and D-enantiomeric forms. Sterile roots of wheat (Triticum aestivum L.) plants were exposed to solutions containing either (14)C-labelled L-alanine, D-alanine, L-trialanine or D-trialanine at a concentration likely to be found in soil solution (10 µM). Over 5 h, plants took up L-alanine, D-alanine and L-trialanine at rates of 0.9±0.3, 0.3±0.06 and 0.3±0.04 µmol g(-1) root DW h(-1), respectively. The rate of N uptake as L-trialanine was the same as that as L-alanine. Plants lost ca.60% of amino acid C taken up in respiration, regardless of the enantiomeric form, but more (ca.80%) of the L-trialanine C than amino acid C was respired. When supplied in solutions of mixed N form, N uptake as D-alanine was ca.5-fold faster than as NO(3)(-), but slower than as L-alanine, L-trialanine and NH(4)(+). Plants showed a limited capacity to take up D-trialanine (0.04±0.03 µmol g(-1) root DW h(-1)), but did not appear to be able to metabolise it. We conclude that wheat is able to utilise L-peptide and D-amino acid N at rates comparable to those of N forms of acknowledged importance, namely L-amino acids and inorganic N. This is true even when solutes are supplied at realistic soil concentrations and when other forms of N are available. We suggest that it may be necessary to reconsider which forms of soil N are important in the terrestrial N cycle.http://europepmc.org/articles/PMC3082556?pdf=render |
| spellingShingle | Paul W Hill Richard S Quilliam Thomas H DeLuca John Farrar Mark Farrell Paula Roberts Kevin K Newsham David W Hopkins Richard D Bardgett David L Jones Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. PLoS ONE |
| title | Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. |
| title_full | Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. |
| title_fullStr | Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. |
| title_full_unstemmed | Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. |
| title_short | Acquisition and assimilation of nitrogen as peptide-bound and D-enantiomers of amino acids by wheat. |
| title_sort | acquisition and assimilation of nitrogen as peptide bound and d enantiomers of amino acids by wheat |
| url | http://europepmc.org/articles/PMC3082556?pdf=render |
| work_keys_str_mv | AT paulwhill acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT richardsquilliam acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT thomashdeluca acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT johnfarrar acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT markfarrell acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT paularoberts acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT kevinknewsham acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT davidwhopkins acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT richarddbardgett acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat AT davidljones acquisitionandassimilationofnitrogenaspeptideboundanddenantiomersofaminoacidsbywheat |