Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans

Many plants develop toxicity symptoms and have reduced growth rates when supplied with ammonium (NH4+) as the only source of inorganic nitrogen. In the present study, the growth, morphology, NH4+ uptake kinetics and mineral concentrations in the tissues of the free-floating aquatic plant Salvinia na...

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Main Authors: Jampeetong A., Brix H.
Format: Article
Language:English
Published: 2014
Online Access:http://www.scopus.com/inward/record.url?eid=2-s2.0-64849084946&partnerID=40&md5=4e410d082a0d5a39ab73a32bb67ab9b8
http://cmuir.cmu.ac.th/handle/6653943832/5892
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spelling th-cmuir.6653943832-58922014-08-30T03:23:35Z Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans Jampeetong A. Brix H. Many plants develop toxicity symptoms and have reduced growth rates when supplied with ammonium (NH4+) as the only source of inorganic nitrogen. In the present study, the growth, morphology, NH4+ uptake kinetics and mineral concentrations in the tissues of the free-floating aquatic plant Salvinia natans (water fern) supplied exclusively with NH4+-N at concentrations of 0.25-15 mM were investigated. S. natans grew well, with relative growth rates of c. 0.25 g g-1 d-1 at external NH4+ concentrations up to 5 mM, but at higher levels growth was suppressed and the plants had small leaves and short roots with stunted growth. The high-affinity transport system (HATS) that mediate NH4+ uptake at dilute NH4+ levels was downregulated at high NH4+ concentrations with lower velocities of maximum uptake (Vmax) and higher half-saturation constants (K1/2). High NH4+ levels also barely affected the concentrations of mineral cations and anions in the plant tissue. It is concluded that S. natans can be characterized as NH4+-tolerant in line with a number of other species of wetland plants as growth was unaffected at NH4+ concentrations as high as 5 mM and as symptoms of toxicity at higher concentrations were relatively mild. Depolarization of the plasma membrane to the equilibrium potential for NH4+ at high external concentrations may be a mechanism used by the plant to avoid excessive futile transmembrane cycling. S. natans is tolerant to the high NH4+ levels that prevail in domestic and agricultural wastewaters, and the inherent high growth rate and the ease of biomass harvesting make S. natans a primary candidate for use in constructed wetland systems for the treatment of various types of nitrogen-rich wastewaters. © 2008 Elsevier B.V. All rights reserved. 2014-08-30T03:23:35Z 2014-08-30T03:23:35Z 2009 Article 09258574 10.1016/j.ecoleng.2008.11.006 ECENE http://www.scopus.com/inward/record.url?eid=2-s2.0-64849084946&partnerID=40&md5=4e410d082a0d5a39ab73a32bb67ab9b8 http://cmuir.cmu.ac.th/handle/6653943832/5892 English
institution Chiang Mai University
building Chiang Mai University Library
country Thailand
collection CMU Intellectual Repository
language English
description Many plants develop toxicity symptoms and have reduced growth rates when supplied with ammonium (NH4+) as the only source of inorganic nitrogen. In the present study, the growth, morphology, NH4+ uptake kinetics and mineral concentrations in the tissues of the free-floating aquatic plant Salvinia natans (water fern) supplied exclusively with NH4+-N at concentrations of 0.25-15 mM were investigated. S. natans grew well, with relative growth rates of c. 0.25 g g-1 d-1 at external NH4+ concentrations up to 5 mM, but at higher levels growth was suppressed and the plants had small leaves and short roots with stunted growth. The high-affinity transport system (HATS) that mediate NH4+ uptake at dilute NH4+ levels was downregulated at high NH4+ concentrations with lower velocities of maximum uptake (Vmax) and higher half-saturation constants (K1/2). High NH4+ levels also barely affected the concentrations of mineral cations and anions in the plant tissue. It is concluded that S. natans can be characterized as NH4+-tolerant in line with a number of other species of wetland plants as growth was unaffected at NH4+ concentrations as high as 5 mM and as symptoms of toxicity at higher concentrations were relatively mild. Depolarization of the plasma membrane to the equilibrium potential for NH4+ at high external concentrations may be a mechanism used by the plant to avoid excessive futile transmembrane cycling. S. natans is tolerant to the high NH4+ levels that prevail in domestic and agricultural wastewaters, and the inherent high growth rate and the ease of biomass harvesting make S. natans a primary candidate for use in constructed wetland systems for the treatment of various types of nitrogen-rich wastewaters. © 2008 Elsevier B.V. All rights reserved.
format Article
author Jampeetong A.
Brix H.
spellingShingle Jampeetong A.
Brix H.
Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
author_facet Jampeetong A.
Brix H.
author_sort Jampeetong A.
title Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
title_short Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
title_full Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
title_fullStr Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
title_full_unstemmed Effects of NH4+ concentration on growth, morphology and NH4+ uptake kinetics of Salvinia natans
title_sort effects of nh4+ concentration on growth, morphology and nh4+ uptake kinetics of salvinia natans
publishDate 2014
url http://www.scopus.com/inward/record.url?eid=2-s2.0-64849084946&partnerID=40&md5=4e410d082a0d5a39ab73a32bb67ab9b8
http://cmuir.cmu.ac.th/handle/6653943832/5892
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