Organic nitrogen enhances nitrogen nutrition and early growth ofPinus sylvestrisseedlings
Open Access
- 28 September 2021
- journal article
- research article
- Published by Oxford University Press (OUP) in Tree Physiology
- Vol. 42 (3), 513-522
- https://doi.org/10.1093/treephys/tpab127
Abstract
Boreal trees are capable of taking up organic nitrogen (N) as effectively as inorganic N. Depending on the abundance of soil N forms, plants may adjust physiological and morphological traits to optimize N uptake. However, the link between these traits and N uptake in response to soil N sources is poorly understood. We examined Pinus sylvestris L. seedlings' biomass growth and allocation, transpiration and N uptake in response to additions of organic N (the amino acid arginine) or inorganic N (ammonium nitrate). We also monitored in situ soil N fluxes in the pots following an addition of N, using a microdialysis system. Supplying organic N resulted in a stable soil N flux, whereas the inorganic N resulted in a sharp increase of nitrate flux followed by a rapid decline, demonstrating a fluctuating N supply and a risk for loss of nitrate from the growth medium. Seedlings supplied with organic N achieved a greater biomass with a higher N content, thus reaching a higher N recovery compared with those supplied inorganic N. In spite of a higher N concentration in organic N seedlings, root-to-shoot ratio and transpiration per unit leaf area were similar to those of inorganic N seedlings. We conclude that enhanced seedlings' nutrition and growth under the organic N source may be attributed to a stable supply of N, owing to a strong retention rate in the soil medium.Keywords
Funding Information
- Knut and Alice Wallenberg Foundation (2018.0259)
- FORMAS (2020-02319)
- Erkko Visiting Professor Programme
This publication has 60 references indexed in Scilit:
- Patterns of Plant Biomass Partitioning Depend on Nitrogen SourcePLOS ONE, 2011
- Uptake of organic nitrogen by plantsNew Phytologist, 2009
- Root uptake of cationic amino acids by Arabidopsis depends on functional expression of amino acid permease 5New Phytologist, 2008
- Nitrate Control of Root Hydraulic Properties in Plants: Translating Local Information to Whole Plant ResponsePlant Physiology, 2008
- Comprehensive Screening of Arabidopsis Mutants Suggests the Lysine Histidine Transporter 1 to Be Involved in Plant Uptake of Amino AcidsPlant Physiology, 2007
- Arabidopsis LHT1 Is a High-Affinity Transporter for Cellular Amino Acid Uptake in Both Root Epidermis and Leaf MesophyllTHE PLANT CELL ONLINE, 2006
- Soil nitrogen form and plant nitrogen uptake along a boreal forest productivity gradientOecologia, 2001
- Plant-microbe competition for soil amino acids in the alpine tundra: effects of freeze-thaw and dry-rewet eventsOecologia, 1998
- Effects of ammonium and nitrate on nutrient uptake and activity of nitrogen assimilating enzymes in western hemlockForest Ecology and Management, 1993
- Root: shoot ratio as a balance between nitrogen productivity and photosynthesisPlant, Cell & Environment, 1987