Uncoupling nitrogen requirements for spring growth from root uptake in a young evergreen shrub (Rhododendron ferrugineum)
• Internal cycling of nitrogen (N) was investigated in a subalpine field population of the evergreen shrub Rhododendron ferrugineum during spring growth. • The foliar nitrogen of 5-yr-old-plants was directly labeled with 15 N and subsequently traced to all plant compartments. In addition, 15 N-a...
| Publié dans: | The New phytologist. - 1979. - 159(2003), 3 vom: 25. Sept., Seite 637-644 |
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| Auteur principal: | |
| Autres auteurs: | , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2003
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Internal cycling Rhododendron ferrugineum evergreen leaf 15N labeling remobilization root uptake spring growth |
| Résumé: | • Internal cycling of nitrogen (N) was investigated in a subalpine field population of the evergreen shrub Rhododendron ferrugineum during spring growth. • The foliar nitrogen of 5-yr-old-plants was directly labeled with 15 N and subsequently traced to all plant compartments. In addition, 15 N-ammonium uptake was estimated in glasshouse experiments. • Before shoot growth, redistribution of 15 N occurred in the plant without net N transfer. During spring development, the decreases in both leaf 15 N and total N were almost identical in terms of percentage, and most of the 15 N withdrawn from the leaf compartments was recovered in the growing shoots. Net changes in the N contents of the various leaf and woody compartments indicate that internal remobilization (especially from 1-yr-old leaves) could have met most of the N needs of new shoot growth. Simultaneously, the rate of mineral N uptake was very low. • Thus, leaves in young plants provide N for new shoots (by contrast with old individuals) and allow, with woody tissues, almost complete uncoupling of N requirement for spring growth from root uptake |
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| Description: | Date Revised 20.04.2021 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1046/j.1469-8137.2003.00830.x |