Ammonia stomatal compensation point of young oilseed rape leaves during dark/light cycles under various nitrogen nutrition
| Autor: | Raia Silvia Massad, Herve Autret, Benjamin Loubet, Andrée Tuzet, Pierre Cellier |
|---|---|
| Přispěvatelé: | Environnement et Grandes Cultures (EGC), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, AgroParisTech-Institut National de la Recherche Agronomique (INRA) |
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
inorganic chemicals
ph [SDV]Life Sciences [q-bio] chemistry.chemical_element xylem nitrogen metabolism 03 medical and health sciences chemistry.chemical_compound Flux (metallurgy) Nitrate parasitic diseases Ammonium Nitrogen cycle 030304 developmental biology 0303 health sciences Ecology Chemistry fungi Xylem food and beverages chamber 04 agricultural and veterinary sciences apoplast Nitrogen Apoplast flux Agronomy Environmental chemistry nh3 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Animal Science and Zoology Agronomy and Crop Science Plant nutrition |
| Zdroj: | Agriculture, Ecosystems and Environment Agriculture, Ecosystems and Environment, Elsevier Masson, 2009, 133 (3/4), pp.170-182. ⟨10.1016/j.agee.2009.04.020⟩ |
| ISSN: | 0167-8809 |
| DOI: | 10.1016/j.agee.2009.04.020⟩ |
| Popis: | 1st NitroEurope Open Science Conference on Reactive Nitrogen and the European Greenhouse Gas Balance, Ghent (Belgique), 20-02-2008/21-02-2008; The plant can be a source or a sink of ammonia (NH3) depending on its nitrogen (N) supply, metabolism and on the background atmospheric concentrations. Thus plants play a major role in regulating atmospheric NH3 concentrations. For a better understanding of the factors influencing the NH3 stomatal compensation point, it is important to analyse the dynamics of leaf NH3 fluxes. The relationship between the leaf NH3 fluxes and the leaf apoplast ammonium and nitrate concentrations, N nutrition and the light and dark periods was studied here. We designed an experiment to quantitatively assess leaf-atmosphere NH3 exchange and the stomatal compensation point and to identify the main factors affecting the variation of NH3 fluxes in oilseed rape. We tested day and night dynamics as well as the effect of five different N treatments. Two experimental methods were used: a dynamic open flux chamber and extraction of the apoplastic solution. Chamber measurements showed that there was a good correlation between plant NH3 fluxes and water fluxes. Compensation points were calculated by two different methods and ranged between 0.8 and 12.2 ?g m-3 NH3 (at 20 °C) for the different N treatments. Apoplastic solution measurements showed that there was no significant differences in the apoplastic NH4+ concentrations ([NH4+]apo) extracted in dark and light periods for the same N treatment. Statistical analysis also showed that [NH4+]apo was correlated with [NH4+] in the nutrient solution and weakly correlated with [NO3-]. Apoplast NH4+ concentrations ranged between 0.1 and 2.1 mM, bulk tissue NH4+ concentrations between 3.9 and 6.6 mM and xylem concentrations between 2.4 and 6.1 mM depending on the N supply. Calculated NH3 emission potential from the extraction measurements were over-estimated when compared with the value calculated from chamber measurements. Errors related to chamber measurements included separation of the cuticular and stomatal fluxes and the calculation of total resistance to NH3 exchange. Errors related to the extraction measurements included assessing the amount of cytoplasmic contamination. We do not have another method to assess the NH3 stomatal compensation point and the choice between these two measurement techniques should depend on the scales to which the measurements apply and the processes to be studied. |
| Databáze: | OpenAIRE |
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