Exudation of organic acids by a marsh plant and implications on trace metal availability in the rhizosphere of estuarine sediments

Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

doi:10.1016/j.ecss.2005.06.007

Cited by 92 publications

(47 citation statements)

References 26 publications

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“…Plant roots can alter physical and chemical properties of the sediment, influencing geochemical fractionation of metals and thus availability to the plant (Caçador et al, 1996b(Caçador et al, , 1999Doyle & Otte, 1997;Lacerda et al, 1997;Otero & Macías, 2002;Mucha et al, 2005). Factors affecting bioavailability of metals to the marsh plants include pH, redox potential, salinity, particle size and organic matter content (Alloway, 1990;Williams et al, 1994a).…”

Section: Introductionmentioning

confidence: 97%

Mobility of metals in salt marsh sediments colonised by Spartina maritima (Tagus estuary, Portugal)

et al. 2008

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Chemical associations of Zn, Pb, Cu, Co and Cd were determined using a sequential extraction procedure in sediments colonised by S. maritima in three salt marshes within the Tagus estuary: Rosário, Corroios and Pancas. Concentrations of these metals were also analysed in above-and belowground parts of Spartina maritima, as well as in sediments colonised by the plant. The highest metal concentrations in sediments were found in the marshes near the industrial and urban areas, whereas metal concentrations in plants were not significantly different among sites. This was thought to be a consequence of differences observed in metal bioavailability: Metals in Pancas, the least polluted location, were largely associated to easily accessible fractions for plant uptake, probably as a result of low organic matter content and high sandy fraction in sediments. S. maritima was able to induce the concentration of metals between its roots in the three salt marshes. The results obtained in this study indicate that S. maritima could be useful to induce phytostabilisation of metals in sediments, although the effectiveness to modify chemical associations is highly dependent on existing sediment parameters, and thus different results could be obtained depending on site characteristics.

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Section: Introductionmentioning

confidence: 97%

Mobility of metals in salt marsh sediments colonised by Spartina maritima (Tagus estuary, Portugal)

et al. 2008

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“…As mentioned also above, the sediment between the root system of J. maritimus showed a higher accumulation capacity for Hg when compared with the sediment between the roots of H. portulacoides. The differences observed in the present study may be attributable to higher oxidising activity of H. portulacoides roots in the sediment when compared with the J. maritimus roots, probably due to fact that roots of J. maritimus liberate exudates (organic acids) that could act as complexing agents for metals, reducing their availability to plants (Mucha et al 2005). Therefore, J. maritimus root exhibited less Hg accumulation compared with roots of H. portulacoides that consequently lead to higher sediment-Hg vegetated by J. maritimus than H. porulacoides-vegetated sediments.…”

Section: Discussionmentioning

confidence: 46%

“…Moreover, these sediment charateristics are also affected by the plant vegetation and the cumulative effect of the processes mentioned above, and thus influence the complex interaction processes between plants and surrounding sediments (Greger 2004;Mucha et al 2005;Almeida et al 2006a, b;Válega et al 2008a, b).…”

Section: Introductionmentioning

confidence: 96%

Impact of Seasonal Fluctuations on the Sediment-Mercury, its Accumulation and Partitioning in Halimione portulacoides and Juncus maritimus Collected from Ria de Aveiro Coastal Lagoon (Portugal)

Anjum

Ahmad

Válega

et al. 2011

Water Air Soil Pollut

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The availability of metals to plants is a complex function of numerous environmental factors. Many of these factors are interrelated, and vary seasonally and temporally. The current study intended to understand the influence of seasonal fluctuations and the vegetation of salt marsh plants (SMPs; Halimione portulacoides, Juncus maritimus) on sediment's mercury (Hg) and its pH and redox potential (Eh), as well as their cumulative effect on the plant's Hg-accumulation and Hg-partitioning potential. The area selected for the study was Laranjo Basin at Ria de Aveiro lagoon (Portugal) where a known Hg gradient was existed due to chlor-alkali plant discharge. Three sampling sites (L1, L2 and L3) were selected along a transect defined by the distance from the main Hg source. Samples were also collected from the Hg-free site (R). Irrespective of the plant vegetation, Hg in sediments gradually increased with a decreasing distance towards Hg-point source. The sediment colonised by J. maritimus showed more Hg concentration compared with H. portulacoides irrespective of the season. As a whole, J. maritimus accumulated Hg more than H. portulacoides at all the sampling sites, whereas in root, stem and leaf, the concentration was ranked as: L1 > L2 > L3 in both the plant species and was differentially influenced by seasonal changes. Moreover, root of both plants exhibited highest Hg concentration compared with stem and leaf. In addition, the leaf of H. portulacoides exhibited more Hg than leaves of J. maritimus. Bioaccumulation and translocation factors and dry weight were differentially influenced by seasonal changes. Taking together the results, the physicochemical properties of sediment especially the sediment-Eh seems to be influnced by the type of plant vegetation and seasonal changes which in turn may have influenced the chemistry of sediments; thus, it enfluences the bioavalability of Hg and the Hgretention capacity of both salt marsh sediments (SMSs) and SMPs (bioaccumulation factor). Moreover, SMSs vegetated by J. maritimus exhibited a stronger capacity for the retention and phytostabilization of Hg belowground (in sediments and/or roots) than those dominated by H. portulacoides. ConverseWater Air Soil Pollut (2011) 222:1-15 ly, those SMSs extensively vegetated by H. portulacoides are expected to translocate more Hg to aboveground parts, acting as a potential source of this metal to the marsh ecosystem. Therefore, J. maritimus and H. portulacoides may be used repectively for phytostabilization (in rhizosediments) and phytoextraction (by accumulation in aboveground plant tissue for subsequent plant removal).

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“…Plants actively modify conditions in the rhizosphere by changes in redox conditions (Jacob and Otte 2004a, b;Mucha et al 2005), mineral precipitation/dissolution (Mucha et al 2010), and exudation of organic substances capable of complexing metals and changing their bioavailability (Parker et al 2001;Hammer and Keller 2002;Berkelaar and Hale 2003;Magdziak et al 2011). Rootexuded LMWOAs influence the behaviour of nutrients and trace metals, either enhancing or reducing their availability, by directly affecting acidification, chelation, precipitation and redox reactions, or indirectly, through their effects on microbial activity, physical and chemical properties of the rhizosphere and root growth pattern (Tao et al 2004;Kidd et al 2009;Li et al 2009).…”

Section: Discussionmentioning

confidence: 99%

Copper phytoextraction with Salix purpurea × viminalis under various Ca/Mg ratios. Part 2. Effect on organic acid, phenolics and salicylic acid contents

et al. 2013

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One-year-old cuttings of basket willow (Salix purpurea 9 viminalis) were cultivated hydroponically under increasing Cu concentrations (0, 1, 2 and 3 mM) and at four Ca/Mg ratios (4:1, 1:10, 20:1 and 1:1 / 4 ). After 14 days, rhizosphere and leaf samples were analysed. Salix plants were able to release relatively high amounts of low molecular weight organic acids (LMWOAs) in a short period of time. The total amount of LMWOAs increased with increasing Cu concentrations. Oxalic and acetic acids were dominant, and act as complexing agents for Cu ions, and therefore, organic exudates should be taken into account in phytoextraction of polluted areas. The Ca/Mg ratio of the medium significantly influenced not only concentration, but also the composition of LMWOAs. Phenolics content in leaves increased with the excess of Ca and Mg and with Cu level in the medium for all Ca/Mg ratios. The accumulation of glucose, fructose and sucrose in leaves was observed for deficiency and excess of Ca and/or Mg and Cu treatment at all Ca/Mg ratios. Excess calcium (Ca/Mg = 20:1) led to strong induction of salicylic acid biosynthesis, probably resulting from enhanced oxidative stress.

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Exudation of organic acids by a marsh plant and implications on trace metal availability in the rhizosphere of estuarine sediments

Cited by 92 publications

References 26 publications

Mobility of metals in salt marsh sediments colonised by Spartina maritima (Tagus estuary, Portugal)

Mobility of metals in salt marsh sediments colonised by Spartina maritima (Tagus estuary, Portugal)

Impact of Seasonal Fluctuations on the Sediment-Mercury, its Accumulation and Partitioning in Halimione portulacoides and Juncus maritimus Collected from Ria de Aveiro Coastal Lagoon (Portugal)

Copper phytoextraction with Salix purpurea × viminalis under various Ca/Mg ratios. Part 2. Effect on organic acid, phenolics and salicylic acid contents

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