Iron (Fe) deficiency in crop plants is a modern agricultural problem worldwide. Although multiple strategies have been evolved to improve Fe assimilation, some plant species, especially dicots and nongraminaceous monocots (strategy I plants), cannot avoid Fe deficiency in low Fe-availability soils. It is well documented that graminaceous plants (strategy II plants) employ the chelationbased Fe ...

Silica gel, sequentially modified with polyhexamethylene guanidine and pyrocatechin-3,5-disulfonic acid (Tiron), was suggested for sorption separation and determination of Fe(III) and Fe(II). It was found that quantitative extraction of Fe(III) and its separation from Fe(II) were attained at pH 2.5-4.0, while quantitative extraction of Fe(II) was observed at pH 6.0-7.5. An intensive signal with...

Biological carbon fixation is limited by the supply of Fe in vast regions of the global ocean. Dissolved Fe in seawater is primarily sourced from continental mineral dust, submarine hydrothermalism, and sediment dissolution along continental margins. However, the relative contributions of these three sources to the Fe budget of the open ocean remains contentious. By exploiting the Fe stable iso...

The effect of Fe fortification on the absorption of Zn was studied by radioisotopic labelling of single meals, followed by measurements of whole-body retention of 65Zn at 14 d after intake. Healthy adult volunteers participated in the study. Weaning cereal, wheat bread and infant formula, foods that are all frequently Fe-fortified, were evaluated in the study. The amounts of Fe added as FeSO4 w...

The influence of lithotrophic Fe(II)-oxidizing bacteria on patterns of ferric oxide deposition in opposing gradients of Fe(II) and O(2) was examined at submillimeter resolution by use of an O(2) microelectrode and diffusion microprobes for iron. In cultures inoculated with lithotrophic Fe(II)-oxidizing bacteria, the majority of Fe(III) deposition occurred below the depth of O(2) penetration. In...

Translocation of Fe was studied in WF9 (Fe-efficient) and ys(1)/ys(1) (Fe-inefficient) maize (Zea mays L.) genotypes. Iron-deficient WF9 translocated more Fe to the tops than Fe-deficient ys(1)/ys(1). Malate and citrate contents of root saps increased nearly 2-fold and aconitate increased over 4-fold in both genotypes as Fe of nutrient solutions increased from 0.1 to 3 milligrams per liter. Rel...

The important question of iron bioavailability in the sea has become complicated by the discovery that marine phytoplankton can take up Fe bound in very stable chelates via reductive processes, and some particular Fe species through specialized transport mechanisms. As a result there is some question of whether the small fraction of Fe that is ‘‘free’’ or unchelated in seawater is important in ...

Equilibrium-dialysis experiments with 59Fe-labelled Fe(III) chelate solutions show that ferritin is capable of binding a limited number of Fe(III) atoms. Some of this Fe(III) is readily removed, but up to about 200 Fe(III) atoms/molecule remain bound after extensive washing. Some exchange of labelled Fe(III) with endogenous unlabelled ferritin Fe occurs during prolonged dialysis against 59Fe(II...

Highly ordered, vertically oriented Fe3+-doped TiO₂ nanotube arrays (Fe-TNTs) were prepared on Ti-Fe alloy substrates with different Fe contents by the electrochemical anodization method. The as-prepared Fe-TNTs were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and related electrochem...