Effect of salinity on the zinc(II) binding efficiency of siderophore functional groups and implications for salinity tolerance mechanisms in barley

Northover, George; Mao, Yiru; Ahmed, Haris; Blasco, Salvador; Vilar, Ramón; Garcı́a-España, Enrique; Weiß, Dominik J.

doi:10.1038/s41598-021-95736-7

Cited by 5 publications

(8 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 4 shows intrinsic stability constants for the formation of [Zn(Cit)] − and [Zn(HCit)] determined (i) using the Davies equation and the conditional association constants determined at different ionic strengths and (ii) fitting the parameterised EDH equation to the full ionic strength dataset. We find statistically significant (p < 0.05) differences for the various logβ 0 , emphasizing that the method used for activity corrections is critical when studying the small changes in speciation happening during geochemical processes in the rhizosphere 3 , 30 , 34 . Intrinsic association constants seem over predicted below 0.1 mol dm −3 and underpredicted above 0.1 mol dm −3 .…”

Section: Resultsmentioning

confidence: 84%

“…These results demonstrate the inconsistencies in speciation calculations that arise when the same geochemical model is run using different sets of stability constants derived by applying the same method (e.g., Davies equation) to different sets of ionic strength data; even when the different sets of ionic strength data are within the activity model’s ionic strength range of applicability, i.e. for Davies equation < 0.5 mol dm −3 and from the same study 3 , 30 , 34 . This is a critical observation for the pH range close to the root.…”

Section: Resultsmentioning

confidence: 99%

“…Potentiometric measurements were carried out at T = 298.1 ± 0.1 K in thermostatic cells. The setup consisted of a Metrohm model 888 Titrando apparatus controlled by Metrohm TiAMO 1.2 software equipped with a combined gel electrode (VWR model 662 1759) 34 . Estimated precision was ± 0.2 mV and ± 0.003 mL for the electromotive force and titrant volume readings, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Another widely applied approach in metal–ligand coordination studies determines conditional stability constants at a number of points within the ionic strength range of interest and uses adjustable parameters to fit the Debye-Hückel model 22 , 26 , 27 . This approach has been termed as direct method or extended Debye Hückel (EDH) model 3 , 22 , 34 . The Debye-Hückel type model is expressed by the equation where is a linear function of ionic strength that can be formulated in different ways.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synergistic use of siderophores and weak organic ligands during zinc transport in the rhizosphere controlled by pH and ion strength gradients

Northover

Mao

Blasco

et al. 2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

Citrate (Cit) and Deferoxamine B (DFOB) are two important organic ligands coexisting in soils with distinct different affinities for metal ions. It has been theorized that siderophores and weak organic ligands play a synergistic role during the transport of micronutrients in the rhizosphere, but the geochemical controls of this process remain unknown. Here we test the hypothesis that gradients in pH and ion strength regulate and enable the cooperation. To this end, first we use potentiometric titrations to identify the dominant Zn(II)–Cit and Zn(II)–DFOB complexes and to determine their ionic strength dependent stability constants between 0 and 1 mol dm−3. We parametrise the Extended Debye-Hückel (EDH) equation and determine accurate intrinsic association constants (logβ0) for the formation of the complexes present. The speciation model developed confirms the presence of [Zn(Cit)]−, [Zn(HCit)], [Zn2(Cit)2(OH)2]4−, and [Zn(Cit)2]4−, with [Zn(Cit)]− and [Zn2(Cit)2(OH)2]4− the dominant species in the pH range relevant to rhizosphere. We propose the existence of a new [Zn(Cit)(OH)3]4− complex above pH 10. We also verify the existence of two hexadentate Zn(II)–DFOB species, i.e., [Zn(DFOB)]− and [Zn(HDFOB)], and of one tetradentate species [Zn(H2DFOB)]+. Second, we identify the pH and ionic strength dependent ligand exchange points (LEP) of Zn with citrate and DFOB and the stability windows for Zn(II)–Cit and Zn(II)–DFOB complexes in NaCl and rice soil solutions. We find that the LEPs fall within the pH and ionic strength gradients expected in rhizospheres and that the stability windows for Zn(II)–citrate and Zn(II)–DFOB, i.e., low and high affinity ligands, can be distinctly set off. This suggests that pH and ion strength gradients allow for Zn(II) complexes with citrate and DFOB to dominate in different parts of the rhizosphere and this explains why mixtures of low and high affinity ligands increase leaching of micronutrients in soils. Speciation models of soil solutions using newly determined association constants demonstrate that the presence of dissolved organic matter and inorganic ligands (i.e., bicarbonate, phosphate, sulphate, or chlorides) do neither affect the position of the LEP nor the width of the stability windows significantly. In conclusion, we demonstrate that cooperative and synergistic ligand interaction between low and high affinity ligands is a valid mechanism for controlling zinc transport in the rhizosphere and possibly in other environmental reservoirs such as in the phycosphere. Multiple production of weak and strong ligands is therefore a valid strategy of plants and other soil organisms to improve access to micronutrients.

show abstract

Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synergistic use of siderophores and weak organic ligands during zinc transport in the rhizosphere controlled by pH and ion strength gradients

Northover

Mao

Blasco

et al. 2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…Desferrioxamine B (DFOB) is a (tris)hydroxamate siderophore widely present in groundwater [19,20]. Its structure is provided in Fig.…”

Section: Methodsmentioning

confidence: 99%

A pilot study on the effect of desferrioxamine B on uranium VI precipitation and dissolution in pH 11.5, 0.1 M NaCl solutions

Kirby

Weiss

2022

J Radioanal Nucl Chem

View full text Add to dashboard Cite

A pilot study investigating the possible role of desferrioxamine B (DFOB) to prevent UVI precipitation in alkaline NaCl solutions was carried out. Desferrioxamine B is a hydroxamate siderophore occurring naturally in the environment. The siderophore can possibly mobilize UVI from a wide range of sources such as mine tailings, contaminated land and radioactive waste storage and disposal facilities. The results from a series of batch experiments covering a wide range of naturally occurring concentrations over relevant time scales (3 days and 2 months) show that DFOB can quantitatively prevent UVI precipitation as ≥ 0.2 μm precipitates when 130 µM and 420 µM of the DFOB is present in solution. The impact is minimized as its concentration decrease to below 10 µM, suggesting these ligands will have a less mobilizing effect on uranium from a geological disposal facility if present in its VI oxidation state.

show abstract

Effect of zinc and protein content in different barley cultivars: use of controlled release matrices

Jiménez‐Rosado

Foggia

Rosignoli

et al. 2023

Renew. Agric. Food Syst.

View full text Add to dashboard Cite

Barley is one of the most consumed cereals, with many different cultivars available worldwide. Like other crops, its yield has been affected by climate change and soil degradation. This work proposes controlled-release protein-based matrices with incorporated zinc to improve barley seed germination and zinc content in the plant. Thus, the main objective of this study was to investigate the use of controlled-release protein-based matrices for massive crops, such as barley. Different barley cultivars of barley were studied: Barke, Golden Promise, Morex, WB-200, WB379, and WB-446. The seeds of each cultivar were also analyzed in order to explain the behavior of plants observed during the growth. To this end, the physico-chemical (FT-IR, Raman spectroscopy, and Zn concentration) and microstructural (SEM) properties of the different seeds were firstly evaluated to establish differences between the studied cultivars. In addition, the use of controlled-release soybean protein-based matrices without zinc (M) or with zinc incorporated (MZ) was evaluated as fertilizers in the different barley cultivars. In this sense, the use of these matrices as a zinc carrier improved seed germination and zinc content in the plants, indicating that the use of matrices improves the amount of zinc assimilated by the crops (up to 30 and 50% with M and MZ, respectively) and allows the proper root growth of all cultivars of barley. In conclusion, this article shows the potential of controlled-release protein-based matrices as substitutes for conventional fertilization.

show abstract

Effect of salinity on the zinc(II) binding efficiency of siderophore functional groups and implications for salinity tolerance mechanisms in barley

Cited by 5 publications

References 64 publications

Synergistic use of siderophores and weak organic ligands during zinc transport in the rhizosphere controlled by pH and ion strength gradients

Synergistic use of siderophores and weak organic ligands during zinc transport in the rhizosphere controlled by pH and ion strength gradients

A pilot study on the effect of desferrioxamine B on uranium VI precipitation and dissolution in pH 11.5, 0.1 M NaCl solutions

Effect of zinc and protein content in different barley cultivars: use of controlled release matrices

Contact Info

Product

Resources

About