Depletion of the heaviest stable N isotope is associated with NH4 +/NH3 toxicity in NH4 +-fed plants

Ariz, Idoia; Cruz, Cristina; Moran, Jose F.; González-Moro, María B; García-Olaverri, Carmen; González-Murua, Carmen; Martins-Loução, Maria A.; Aparicio-Tejo, Pedro M.
January 2011
BMC Plant Biology;2011, Vol. 11 Issue 1, p83
Academic Journal
Background: In plants, nitrate (NO3-) nutrition gives rise to a natural N isotopic signature (δ15N), which correlates with the δ15N of the N source. However, little is known about the relationship between the δ15N of the N source and the 14N/15N fractionation in plants under ammonium (NH4+) nutrition. When NH4+ is the major N source, the two forms, NH4+ and NH3, are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH3 (g) and NH4+ (aq) which drives to a different δ15N. Nine plant species with different NH4+-sensitivities were cultured hydroponically with NO3- or NH4+ as the sole N sources, and plant growth and δ15N were determined. Short-term NH4+/NH3 uptake experiments at pH 6.0 and 9.0 (which favours NH3 form) were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH4+ and NH3. Results: Several NO3--fed plants were consistently enriched in 15N, whereas plants under NH4+ nutrition were depleted of 15N. It was shown that more sensitive plants to NH4+ toxicity were the most depleted in 15N. In parallel, N-deficient pea and spinach plants fed with 15NH4+ showed an increased level of NH3 uptake at alkaline pH that was related to the 15N depletion of the plant. Tolerant to NH4+ pea plants or sensitive spinach plants showed similar trend on 15N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO3 as control discarded that the differences observed arise from pH detrimental effects. Conclusions: This article proposes that the negative values of d15N in NH4+-fed plants are originated from NH3 uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH4+/NH3 toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH4+ may have two components: one that transports N in the molecular form and is associated with fractionation and another that transports N in the ionic form and is not associated with fractionation.


Related Articles

  • Effects of nutrition strategy on the levels of nutrients and bioactive compounds in blackberries. Ali, Liaqat; Alsanius, Beatrix; Rosberg, Anna; Svensson, Birgitta; Nielsen, Tim; Olsson, Marie // European Food Research & Technology;Jan2012, Vol. 234 Issue 1, p33 

    The effects of nutrition strategy on levels of nutrients and bioactive compounds in fruit and leaves of blackberries were studied in greenhouse-grown blackberry plants fertilised with combinations of two levels (low, high) of nitrogen (60 and 100 kg ha, respectively) and potassium (66.4 and 104...

  • The Influence of Certain Physical and Chemical Variables on the Seasonal Dynamics of Phytoplankton Assemblages of a Source Inlet and the Outlet of the Shallow Hypertrophic Lake Manyas, Turkey. Çelİk, Kemal; Ongun, Tuğba // Turkish Journal of Botany;2007, Vol. 31 Issue 6, p485 

    The relationships between water discharge, temperature, pH, conductivity, turbidity, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of one of the inlets, which is a source of waste for the lake, and the sole outlet of the shallow hypertrophic Lake Manyas,...

  • Plant nutrient solution pH changes. Hershey, David R. // Journal of Biological Education (Society of Biology);Summer92, Vol. 26 Issue 2, p107 

    Investigates plant nutrient solution pH changes. Effect of pH change on plant growth; Experimental procedure; Reason for changes in root pH; Root absorption of anions and cations in nitrate nutrient solution; Factors affecting pH changes.

  • Interação entre silício e nitrogênio em arroz cultivado sob solução nutritiva. Ávila, William Fabrício; Pereira Baliza, Danielle; Faquin, Valdemar; Lopes Araújo, Josinaldo; Junio Ramos, e Sílvio // Revista Ciência Agronômica;Apr2010, Vol. 41 Issue 2, p184 

    The present study aimed to evaluate the interaction effect between silicon and nitrogen in the content of chlorophyll, nitrate, ammonium and total nitrogen, dry matter production, number of tillers and number of panicles rice–plant cultivated in nutritional solution. A factorial design 5...

  • THE EFFECTS OF pH AND ADDITION OF AN ORGANIC BUFFER (HEPES) ON NITRATE TRANSFORMATION IN FE[sup 0]-WATER SYSTEMS. Zawaideh, Lara L.; Zhang, Tian C. // Water Science & Technology;1998, Vol. 38 Issue 7, p107 

    Investigates the effects of hydrogen-ion concentration and addition of an organic buffer on nitrate transformation in iron-water systems. Nitrate removal; Nitrate contamination; Methods for water remediation.

  • Production of medium chain length polyhydroxyalkanoates by fed-batch culture of Pseudomonas oleovorans. Kim, Beom Soo // Biotechnology Letters;Jan2002, Vol. 24 Issue 2, p125 

    Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHAs) from octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate in the culture broth was maintained below 4 g l-1 by...

  • Sludge reduction and performance analysis of a modified sludge reduction process. Zhen Zhou; Weimin Qiao; Can Xing; Yingjun Wang; Chunying Wang; Yifang Wang; Yiru Wang; Luochun Wang // Water Science & Technology;2014, Vol. 69 Issue 5, p934 

    A modified sludge process reduction activated sludge (SPRAS) technology was developed by inserting a sludge process reduction (SPR) module, composed of an aeration tank and a settler, before the activated sludge system was proposed in this study. Compared with the anaerobic/ anoxic/aerobic (AAO)...

  • Modeling of glutamic acid production by Lactobacillus plantarum MNZ. Zareian, Mohsen; Ebrahimpour, Afshin; Sabo Mohamed, Abdul Karim; Saari, Nazamid // Electronic Journal of Biotechnology;2013, Vol. 16 Issue 4, p1 

    Background: L-glutamic acid, the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism acts as a precursor of γ-amino butyric acid (GABA). In the present study, culture condition for enhanced glutamic acid production by Lactobacillus plantarum MNZ was...

  • Ammonium Nutrition as a Strategy for Cadmium Mobilisation in the Rhizosphere of Sunflower. Zaccheo, Patrizia; Crippa, Laura; Di Muzio Pasta, Valeria // Plant & Soil;May2006, Vol. 283 Issue 1/2, p43 

    Ammonium nutrition of higher plants results in rhizosphere acidification due to proton excretion by root cells. The acidification induced by ammonium-fed plants can be exploited to promote a localised metal mobilisation in neutral to alkaline polluted soils and therefore to improve...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics