Pattern Of Iron Distribution Research Articles

Spatiotemporal distribution patterns of iron, manganese, and arsenic within the river infiltration zone and the potential geochemical activity at key interfaces

The river infiltration zone is a mixed area of surface water and groundwater under the riverbed and along the riverbank, which is greatly affected by river infiltration. Currently, there is a lack of understanding regarding the migration and transformation processes of Fe, Mn, and As, along with their correlation with organic carbon in the river infiltration zone affected by riverbed scouring and siltation processes. In this study, based on techniques such as pore water sampling and the Tessier sequential extraction, the spatiotemporal variations in Fe, Mn, and As concentrations and possible geochemical processes at the riverbed sediment–water interface and along the river infiltration flow path were revealed. The results indicated that the potential geochemical activity of Fe, Mn, and As and the distribution of organic carbon in the riverbed sediment responded to riverbed scouring–siltation processes. Compared to the high water level period, the potential geochemical activity of Fe, Mn, As, and organic carbon in the riverbed sediment generally exhibited an upward trend during the low water level period, indicating more intense Fe and Mn biogeochemical reactions. During river infiltration, the labile organic carbon (LOC) was preferentially utilized, and with increasing depth, the sedimentary organic carbon (SOC) continuously transformed into LOC and dissolved organic carbon (DOC). Affected by riverbed scouring processes, the transition time from oxidizing to reducing conditions in the pore water increased, and the Fe, Mn, and As reduction zones moved deeper and farther from the riverbank, resulting in a significant expansion of the groundwater pollution area. The reductive dissolution of iron and manganese oxides/hydroxides and the oxidation of organic matter–bound Fe, Mn, and As were the main biogeochemical processes contributing to the release of Fe, Mn, and As in the river infiltration zone. These research results have crucial theoretical significance and practical application value for the sustainable utilization of groundwater resources and the remediation of groundwater pollution.

MRI assessment of different types of chronic demyelinating lesions in patients with multiple sclerosis using quantitative susceptibility mapping (QSM)

Histologically, chronic demyelinating lesions in multiple sclerosis (MS) have been shown to include inactive lesions that do not change over time and active or “smouldering" lesions that tend to enlarge over time and are surrounded by pro-inflammatory activated microglial cells that are loaded with iron. To identify “smouldering" foci of demyelination and assess the “latent” inflammatory process in the brain, MRI sequences sensitive to the detection of substances with paramagnetic properties, including iron, must be used. They include an innovative technique such as quantitative susceptibility mapping (QSM).Objective: to identify, using MRI different types of chronic demyelination foci in MS, based on iron distribution and the degree of damage (myelination) in their structure.Material and methods. The patterns of iron distribution in demyelinating lesions in 90 MS patients were investigated using QSM. In addition, two lesions with different iron distribution patterns were randomly selected on the QSM map for each patient, in which the magnetic transfer ratio (MTR), indirectly reflecting the degree of myelination, was calculated. The identified changes were also compared with visualization of lesions in standard MRI modes (T1 MPRAGE, T2 FLAIR).Results. Despite the predominantly identical visualization in T2 FLAIR mode, chronic foci of demyelination show different patterns on the QSM maps, which is due to the peculiarities of iron distribution: some foci are not detected on QSM, while others are visualized either in the form of a homogeneous or a ring-shaped pattern. When comparing QSM data with MTR, it was found that MTR indicators were highest in non-visualized lesions (demyelination is minimal), while damage was most pronounced in lesions with ring-shaped iron distribution.Conclusion. Different patterns of iron distribution in demyelination foci compared to the degree of myelination in these foci according to MTR were identified using QSM, which is of great importance for the evaluation of latent inflammation and the development of the neurodegenerative process in MS.

Clinical and pathological features of brain iron metabolism in neurodegerative and demyelinating disorders

The results of many modern studies show the significance of the role of changes in iron metabolism and its increased accumulation in the pathogenesis of neurodegenerative and demyelinating diseases. Determining the role of iron metabolism and the characteristics of its distribution in strategically important areas of the brain in diseases of the nervous system is important from a diagnostic point of view, since it can help determine the rate of disease progression and, accordingly, correction of therapy. The article presents modern literature data describing the main disorders of iron metabolism in the structure of the pathogenesis of neurodegenerative diseases (Alzheimer’s disease and Parkinson’s disease), and demyelinating diseases, in particular, multiple sclerosis. Attention is drawn to the role of changes in iron metabolism in the pathogenesis of the process of regulated cell death, ferroptosis, accompanied by depletion of intracellular glutathione, decreased activity of the enzyme glutathione peroxidase-4 and the subsequent process of lipid peroxidation caused by a decrease in the protective antioxidant system of cells and the accumulation of reactive oxygen species. Attention is drawn to the role of the Fenton reaction in the accumulation of free radicals, the oxidation of iron and, as a consequence, its excessive deposition in brain structures. Information is provided on the features of the pathogenesis of neuronal iron accumulation, modern diagnostic capabilities for assessing iron content in strategically important areas of the brain using various methods, and the possibility of various options for therapeutic treatment of these conditions is considered. Attention is drawn to the patterns of iron distribution in normal brain structures depending on age, as well as in the specified nosologies. Data are presented on the connection between an increase in the amount of iron content in brain cells and the severity of clinical manifestations of diseases. Attention is drawn to the relationship between the progression of disease severity and the increase in metal content in the cells of strategically significant areas of the brain. When writing the article, modern materials and meta-analyses were used, containing the results of a significant number of studies devoted to the problem considered in this review.

Multimodal anatomical mapping of subcortical regions in marmoset monkeys using high-resolution MRI and matched histology with multiple stains

Subcortical nuclei and other deep brain structures play essential roles in regulating the central and peripheral nervous systems. However, many of these nuclei and their subregions are challenging to identify and delineate in conventional MRI due to their small size, hidden location, and often subtle contrasts compared to neighboring regions. To address these limitations, we scanned the whole brain of the marmoset monkeys in ex vivo using a clinically feasible diffusion MRI method, called the mean apparent propagator (MAP)-MRI, along with T2W and MTR (T1-like contrast) images acquired at 7 Tesla. Additionally, we registered these multimodal MRI volumes to the high-resolution images of matched whole-brain histology sections with seven different stains obtained from the same brain specimens. At high spatial resolution, the microstructural parameters and fiber orientation distribution functions derived with MAP-MRI can distinguish the subregions of many subcortical and deep brain structures, including fiber tracts of different sizes and orientations. The good correlation with multiple but distinct histological stains from the same brain serves as a thorough validation of the structures identified with MAP-MRI and other MRI parameters. Moreover, the anatomical details of deep brain structures found in the volumes of MAP-MRI parameters are not visible in conventional T1W or T2W images. The high-resolution mapping using novel MRI contrasts, combined and correlated with histology, can elucidate structures that were previously invisible radiologically. Thus, this multimodal approach offers a roadmap toward identifying salient brain areas in vivo in future neuroradiological studies. It also provides a useful anatomical standard reference for the region definition of subcortical targets and the generation of a 3D digital template atlas for the marmoset brain research (Saleem et al., 2023). Additionally, we conducted a cross-species comparison between marmoset and macaque monkeys using results from our previous studies (Saleem et al., 2021). We found that the two species had distinct patterns of iron distribution in subregions of the basal ganglia, red nucleus, and deep cerebellar nuclei, confirmed with T2W MRI and histology.

Quantitation of Brain and Blood Glutathione and Iron in Healthy Age Groups Using Biophysical and In Vivo MR Spectroscopy: Potential Clinical Application.

The antioxidant glutathione (GSH) and pro-oxidant iron levels play a balancing role in the modulation of oxidative stress (OS). There is a significant depletion of GSH in the left hippocampus (LH) in patients with Alzheimer's disease (AD) with concomitant elevation of iron level. However, the correlation of GSH and iron distribution patterns between the brain and the peripheral system (blood) is not yet known. We measured GSH and magnetic susceptibility (e.g., iron) in the LH region along with GSH in plasma and iron in serum across four age groups consisting of healthy volunteers (age range 18-72 y, n = 70). We report non-variability of the mean GSH in the plasma and LH region across mentioned age groups. The mean iron level in the LH region does not change, but the iron level in the serum in the 51-72 y age group increases non-significantly. Regression analysis of our data indicated that GSH and iron levels (both in blood and in brain) are not related to age. This research pave the way for the identification of a risk/susceptibility biomarker for AD and Parkinson's disease from the evaluation of GSH (in plasma) and iron (in serum) levels concomitantly.

The effect of the chelated form of iron on its mobility and phytodavailability when applied to the soil

In spite of well-known mechanisms of iron consumption by plants from the soil and action patterns of iron ions in the soils, the work to eliminate the deficiency of this trace element in plants is still relevant. The article presents an assessment of the effect of iron (III) chelate complexes with diethylenetriaminepentaacetic acid (DTPА Fe) and ethylenediaminetetraacetic acid (EDTA Fe) on the mobility and availability of iron for plants in soil with a pH close to neutral. In a model experiment with using of drainage columns, there were established the patterns of iron distribution in the soil and its removal with irrigation water from the root zone of plants (10 cm). Against the background of similar distribution of iron in the soil, a higher content of its mobile forms in the lower layers was noted when using EDTA Fe. The leaching of iron from the soil was confirmed using both DTPA Fe and EDTA Fe. The vegetation experiment revealed the effect of chelate forms on the accumulation of iron in barley plants (Hordeum vulgare L.) during their early growth period (11 days). The iron content in the shoots varied from 120 to 140 µg/g, in the roots – from 233 to 244 µg/g, with a content of 200 µg/g in the control sample. A significant contribution to the accumulation of iron in barley seedlings was observed at the level of the root system in the experiment with EDTA Fe. Data on the accumulation of iron in barley roots were correlated (r = 0.99) with data on their ash content.

B3 Transcription Factors Determine Iron Distribution and FERRITIN Gene Expression in Embryo but Do Not Control Total Seed Iron Content.

Iron is an essential micronutrient for humans and other organisms. Its deficiency is one of the leading causes of anemia worldwide. The world health organization has proposed that an alternative to increasing iron content in food is through crop biofortification. One of the most consumed part of crops is the seed, however, little is known about how iron accumulation in seed occurs and how it is regulated. B3 transcription factors play a critical role in the accumulation of storage compounds such as proteins and lipids. Their role in seed maturation has been well characterized. However, their relevance in accumulation and distribution of micronutrients like iron remains unknown. In Arabidopsis thaliana and other plant models, three master regulators belonging to the B3 transcription factors family have been identified: FUSCA3 (FUS3), LEAFY COTYLEDON2 (LEC2), and ABSCISIC ACID INSENSITIVE 3 (ABI3). In this work, we studied how seed iron homeostasis is affected in B3 transcription factors mutants using histological and molecular approaches. We determined that iron distribution is modified in abi3, lec2, and fus3 embryo mutants. For abi3-6 and fus3-3 mutant embryos, iron was less accumulated in vacuoles of cells surrounding provasculature compared with wild type embryos. lec2-1 embryos showed no difference in the pattern of iron distribution in hypocotyl, but a dramatic decrease of iron was observed in cotyledons. Interestingly, for the three mutant genotypes, total iron content in dry mutant seeds showed no difference compared to wild type. At the molecular level, we showed that genes encoding the iron storage ferritins proteins are misregulated in mutant seeds. Altogether our results support a role of the B3 transcription factors ABI3, LEC2, and FUS3 in maintaining iron homeostasis in Arabidopsis embryos.

Automated Differentiation of Atypical Parkinsonian Syndromes Using Brain Iron Patterns in Susceptibility Weighted Imaging.

In recent studies, iron overload has been reported in atypical parkinsonian syndromes. The topographic patterns of iron distribution in deep brain nuclei vary by each subtype of parkinsonian syndrome, which is affected by underlying disease pathologies. In this study, we developed a novel framework that automatically analyzes the disease-specific patterns of iron accumulation using susceptibility weighted imaging (SWI). We constructed various machine learning models that can classify diseases using radiomic features extracted from SWI, representing distinctive iron distribution patterns for each disorder. Since radiomic features are sensitive to the region of interest, we used a combination of T1-weighted MRI and SWI to improve the segmentation of deep brain nuclei. Radiomics was applied to SWI from 34 patients with a parkinsonian variant of multiple system atrophy, 21 patients with cerebellar variant multiple system atrophy, 17 patients with progressive supranuclear palsy, and 56 patients with Parkinson’s disease. The machine learning classifiers that learn the radiomic features extracted from iron-reflected segmentation results produced an average area under receiver operating characteristic curve (AUC) of 0.8607 on the training data and 0.8489 on the testing data, which is superior to the conventional classifier with segmentation using only T1-weighted images. Our radiomic model based on the hybrid images is a promising tool for automatically differentiating atypical parkinsonian syndromes.

An Updated Overview of the Magnetic Resonance Imaging of Brain Iron in Movement Disorders

Brain iron load is one of the most important neuropathological hallmarks in movement disorders. Specifically, the iron provides most of the paramagnetic metal signals in the brain and its accumulation seems to play a key role, although not completely explained, in the degeneration of the basal ganglia, as well as other brain structures. Moreover, iron distribution patterns have been implicated in depicting different movement disorders. This work reviewed current literature on Magnetic Resonance Imaging for Brain Iron Detection and Quantification (MRI-BIDQ) in neurodegenerative processes underlying movement disorders.

Responses of Intestinal Microbiota and Immunity to Increasing Dietary Levels of Iron Using a Piglet Model.

Iron is an essential metal for both animals and microbiota. In general, neonates and infants of humans and animals are at the risk of iron insufficiency. However, excess dietary iron usually causes negative impacts on the host and microbiota. This study aimed to investigate overloaded dietary iron supplementation on growth performance, the distribution pattern of iron in the gut lumen and the host, intestinal microbiota, and intestine transcript profile of piglets. Sixty healthy weaning piglets were randomly assigned to six groups: fed on diets supplemented with ferrous sulfate monohydrate at the dose of 50 ppm (Fe50 group), 100 ppm (Fe100 group), 200 ppm (Fe200 group), 500 ppm (Fe500 group), and 800 ppm (Fe800), separately, for 3 weeks. The results indicated that increasing iron had no significant effects on growth performance, but increased diarrheal risk and iron deposition in intestinal digesta, tissues of intestine and liver, and serum. High iron also reduced serum iron-binding capacity, apolipoprotein, and immunoglobin A. The RNA-sequencing analysis revealed that iron changed colonic transcript profile, such as interferon gamma-signal transducer and activator of transcription two-based anti-infection gene network. Increasing iron also shifted colonic and cecal microbiota, such as reducing alpha diversity and the relative abundance of Clostridiales and Lactobacillus reuteri and increasing the relative abundance of Lactobacillus and Lactobacillus amylovorus. Collectively, this study demonstrated that high dietary iron increased diarrheal incidence, changed intestinal immune response-associated gene expression, and shifted gut microbiota. The results would enhance our knowledge of iron effects on the gut and microbiome in piglets and further contribute to understanding these aspects in humans.

Mesenchymal iron deposition is associated with adverse long-term outcome in non-alcoholic fatty liver disease.

Background & AimsApproximately one‐third of patients with non‐alcoholic fatty liver disease (NAFLD) show signs of mild‐to‐moderate iron overload. The impact of histological iron deposition on the clinical course of patients with NAFLD has not been established.Methods & ResultsFor this retrospective study, 299 consecutive patients with biopsy‐proven NAFLD and a mean follow‐up of 8.4 (±4.1; range: 0.3‐18.0) years were allocated to one of four groups according to presence of hepatic iron in the reticuloendothelial system (RES) and/or hepatocytes (HC): 156 subjects (52%) showed no stainable iron (NONE), 58 (19%) exclusively reticuloendothelial (xRES), 19 (6%) exclusively hepatocellular (xHC) and 66 (22%) showed a mixed (HC/RES) pattern of iron deposition. A long‐term analysis for overall survival, hepatic, cardiovascular or extrahepatic‐malignant events was conducted. Based on multivariate Cox proportional hazards models any reticuloendothelial iron was associated with fatal and non‐fatal hepatic events. Specifically, xRES showed a cause‐specific hazard ratio (csHR) of 2.4 (95%‐CI, 1.0‐5.8; P = .048) for hepatic as well as cardiovascular fatal and non‐fatal events combined (csHR 3.2; 95%‐CI, 1.2‐8.2; P = .015). Furthermore, the mixed HC/RES iron pattern showed a higher rate of combined hepatic fatal and non‐fatal events (csHR 3.6; 95%‐CI, 1.4‐9.5; P = .010), while xHC iron deposition was not associated with any defined events.ConclusionsThe presence of reticuloendothelial‐accentuated hepatic iron distribution patterns is associated with detrimental long‐term outcomes reflected in a higher rate of both liver‐related and cardiovascular fatal and non‐fatal events.

Quantitative MRI and laser ablation-inductively coupled plasma-mass spectrometry imaging of iron in the frontal cortex of healthy controls and Alzheimer’s disease patients

Accumulation of iron within the cortex of Alzheimer’s disease (AD) patients has been reported by numerous MRI studies using iron-sensitive methods. Validation of iron-sensitive MRI is important for the interpretation of in vivo findings. In this study, the relation between the spatial iron distribution and T2∗-weighted MRI in the human brain was investigated using a direct comparison of spatial maps of iron as detected by T2∗-weighted MRI, iron histochemistry and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), in postmortem brain tissue of the medial frontal gyrus of three control subjects and six AD patients. In addition, iron levels measured by LA-ICP-MS and three quantitative MRI methods, namely R2∗ (=1/T2∗), image phase and quantitative susceptibility mapping (QSM), were compared between 19 AD and 11 controls.Histochemistry results we obtained with the modified Meguro staining were highly correlated with iron levels as detected by LA-ICP-MS (r2 ​= ​0.82, P ​< ​0.0001). Significant positive correlations were also found between LA-ICP-MS and the three quantitative MRI measurements: R2∗ (r2 ​= ​0.63), image phase (r2 ​= ​0.70) and QSM (r2 ​= ​0.74 (all p ​< ​0.0001)). R2∗ and QSM showed the strongest correlation with iron content; the correlation of phase with iron clearly showed increased variation, probably due to its high orientation dependence. Despite the obvious differences in iron distribution patterns within the cortex between AD patients and controls, no overall significant differences were found in iron as measured by LA-ICP-MS, nor in R2∗, phase or susceptibility.In conclusion, our results show that histochemistry as well as quantitative MRI methods such as R2∗ mapping and QSM provide reliable measures of iron distribution in the cortex. These results support the use of MRI studies focusing on iron distribution in both the healthy and the diseased brain.

Distribution patterns of iron supplied by river flow in Petrozavodsk Bay of Lake Onego

Distribution patterns of iron supplied by river flow in Petrozavodsk Bay of Lake Onego

Iron distribution and histopathological study of the effects of deferoxamine and deferiprone in the kidneys of iron overloaded β-thalassemic mice

Renal glomerular and tubular dysfunctions have been reported with high prevalence in β-thalassemia. Iron toxicity is implicated in the kidney damage, which may be reversed by iron chelation therapy. To mimic heavy iron overload and evaluate the efficacy of iron chelators in the patients, iron dextran (180mg iron/mouse) was intraperitoneally (i.p.) injected in heterozygous β-globin knockout mice (muβth−3/+, BKO) and wild type mice (C57BL/6J, WT) over a period of 2 weeks, followed by daily i.p. injection of deferoxamine (DFO) or deferiprone (L1) for 1 week. In BKO mice, iron preferentially accumulated in the proximal tubule with a grading score of 0–1 and increased to grade 3 after iron loading. In contrast, iron mainly deposited in the glomerulus and interstitial space in iron overloaded WT mice. Increased levels of kidney lipid peroxidation, glomerular and medullar damage and fibrosis in iron overloaded mice were reversed by treatment with iron chelators. L1 showed higher efficacy than DFO in reduction of glomerular iron, which was supported by a significantly decreased the amount of glomerular damage. Notably, DFO and L1 demonstrated a distinct pattern of iron distribution in the proximal tubule of BKO mice. In conclusion, chelation therapy has beneficial effects in iron-overloaded kidneys. However, the defect of kidney iron metabolism in thalassemia may be a determining factor of the treatment outcome in individual patients.

A Comparative Analysis of the Microfabrics of Surface Horizons and Desert Varnish in Extremely Arid Soils of the Mojave (USA) and Trans-Altai Gobi (Mongolia) Deserts

The mineralogical composition of coarse fraction and characteristic features of the micro- and submicrofabrics and chemical composition of desert varnish on gravels of desert pavements and the underlying vesicular crust soil horizons were studied in the extremely arid soils of the Mojave (USA) and Trans-Altai Gobi (Mongolia) deserts. A set of common diagnostic features of elementary pedogenetic processes was identified in the automorphic desert soils developed on ancient (70–90 ka) piedmont plains composed of alluvial deposits with the high content of red-earth clay. The results of this study attest to the long and complicated history of the extremely arid soils with alternation of the humid and arid phases of pedogenesis reflected in a specific combination of textural (clay-illuvial) and carbonate pedofeatures and in the distribution patterns of iron, manganese, titanium, and barium in different layers of the desert varnish. The chemical composition of the latter did not depend on the mineralogical composition of the underlying substrates and was formed with active participation of soil microorganisms. This allowed us to conclude about the polygenetic (accretionary–microbiological) nature of desert varnish.

Elemental composition of soils and bottom sediments in streams of the eastern macroslope of the Subpolar Urals

A study is made of the lead, zinc, copper, manganese, chromium, nickel and iron distribution patterns in soils and bottom sediments of streams flowing on the eastern macroslope of the Subpolar Urals. Results were subjected to a statistical processing to show a wide variation in content levels of metals due to a set of lithological and landscape-geochemical factors. The study revealed a correlation of anomalously high concentrations in soils with occurrence zones of ore mineral resources. Particular attention is paid to the lateral differentiation of lead. It is shown that its accumulation occurs in accumulative landscapes of river valleys, and its increased content is observed in bottom sediments during deposition on the sorption barrier. It is found that formation of bottom sediments showing increased contents of metals is associated with sedimentation characteristics at the time when the flow velocity of rivers decreases at the transition from mountain landscapes to lowland landscapes. The accmulation of elements in different components of migration series is analyzed to reveal regular differences in elemental composition of soils of middle- and low-mountain, low-mountain/ piedmont and submontane-lowland landscapes and to permit the description of the background geochemical associations. Regional percent abundances are calculated and compared with results obtained for neighboring areas of the West Siberian Plain. The postulate concerning the determining role of the surrounding mountains in the formation of the trace element composition of soils in Western Siberia. A deficit of copper and zinc content in bottom sediments is pointed out. It is concluded that dissolved forms are dominant in the aquatic transport of heavy metals.

Tissue Iron Distribution Assessed by MRI in Patients with Iron Loading Anemias.

Bone marrow, spleen, liver and kidney proton transverse relaxation rates (R2), together with cardiac R2* from patients with sickle cell disease (SCD), paroxysmal nocturnal hemoglobinuria (PNH) and non-transfusion dependent thalassemia (NTDT) have been compared with a control group. Increased liver and bone marrow R2 values for the three groups of patients in comparison with the controls have been found. SCD and PNH patients also present an increased spleen R2 in comparison with the controls. The simultaneous measurement of R2 values for several tissue types by magnetic resonance imaging (MRI) has allowed the identification of iron distribution patterns in diseases associated with iron imbalance. Preferential liver iron loading is found in the highly transfused SCD patients, while the low transfused ones present a preferential iron loading of the spleen. Similar to the highly transfused SCD group, PNH patients preferentially accumulate iron in the liver. A reduced spleen iron accumulation in comparison with the liver and bone marrow loading has been found in NTDT patients, presumably related to the differential increased intestinal iron absorption. The correlation between serum ferritin and tissue R2 is moderate to good for the liver, spleen and bone marrow in SCD and PNH patients. However, serum ferritin does not correlate with NTDT liver R2, spleen R2 or heart R2*. As opposed to serum ferritin measurements, tissue R2 values are a more direct measurement of each tissue’s iron loading. This kind of determination will allow a better understanding of the different patterns of tissue iron biodistribution in diseases predisposed to tissue iron accumulation.

Impact of fortification with iron salts and vitamin A on the physicochemical properties of laboratory‐pasteurised toned milk and bioaccessibility of the added nutrients

The sensory and physicochemical attributes of pasteurised milk fortified with soluble ferric pyrophosphate (FPP) (25 mg/L iron) and vitamin A (2500 IU) were comparable to unfortified control samples. The heat coagulation time (HCT) of fortified milks was comparable to the control and exhibited a type A curve with HCT–pH maxima at the acidic side of the natural pH. The distribution pattern of iron in different milk fractions was similar in control and fortified milk samples. The bioaccessibility of iron, estimated through in vitro digestibility of milk fortified with vitamin A and iron, was found to be slightly higher than that of milk fortified with iron alone.

Uptake and Distribution of Iron from Different Iron Sources Applied as Foliar Sprays to Chlorotic Leaves of Low-Chill Peach Cultivars

A greenhouse experiment was carried out to examine the uptake and distribution pattern of iron applied through different iron sources to chlorotic leaves of three low-chill peach cultivars viz. Saharanpur Prabhat, Shan-e-Punjab, and Pratap. The plants were grown in sandy loam soil containing 30 g CaCO3 kg−1 soil in plastic pots. Upon the onset of iron deficiency symptoms, separate foliar spray treatments were given using Fe-sulfate [0.5 % (w/v) and 1.0 % (w/v)], Fe-citrate [0.5 % (w/v) and 1.0 % (w/v)], and Fe-EDTA [0.1 % (w/v) and 0.2 % (w/v)] in addition to the control which received foliar spray of only distilled water. All the spray solutions except distilled water were radiolabeled with 59FeCl3. Seven days after imposition of the treatments, iron uptake and distribution was monitored. Among Fe sources, the highest Fe uptake and its distribution in the leaves were recorded with Fe-sulfate followed by Fe-citrate and FeEDTA. Among the low-chill peach cultivars, the highest Fe uptake and distribution was observed with 1.0 % (w/v) Fe-sulfate in Saharanpur Prabhat followed by Shan-e-Punjab and Pratap. The least uptake and distribution of Fe was recorded with 0.1 % (w/v) FeEDTA as iron source in the cultivar Pratap. The highest increase in physiologically active iron (Fe2+) content as well as total iron content of the leaves was also observed with the application of 1.0 % (w/v) Fe-sulfate. However, the level of physiologically active (Fe2+) iron content with 1.0 % (w/v) Fe-sulfate was found to be statistically similar the application of 0.5 % (w/v) Fe-sulfate. The leaf penetration capacity of iron and subsequent distribution of iron from different iron sources in different low-chill peach cultivars were found in the following order Fe-sulfate > Fe-citrate > Fe-EDTA.

Pattern of iron distribution in maternal and filial tissues in wheat grains with contrasting levels of iron

Iron insufficiency is a worldwide problem in human diets. In cereals like wheat, the bran layer of the grains is an important source of iron. However, the dietary availability of iron in wheat flour is limited due to the loss of the iron-rich bran during milling and processing and the presence of anti-nutrients like phytic acid that keep iron strongly chelated in the grain. The present study investigated the localization of iron and phosphorus in grain tissues of wheat genotypes with contrasting grain iron content using synchrotron-based micro-X-ray fluorescence (micro-XRF) and micro-proton-induced X-ray emission (micro-PIXE). X-ray absorption near-edge spectroscopy (XANES) was employed to determine the proportion of divalent and trivalent forms of Fe in the grains. It revealed the abundance of oxygen, phosphorus, and sulphur in the local chemical environment of Fe in grains, as Fe-O-P-R and Fe-O-S-R coordination. Contrasting differences were noticed in tissue-specific relative localization of Fe, P, and S among the different genotypes, suggesting a possible effect of localization pattern on iron bioavailability. The current study reports the shift in iron distribution from maternal to filial tissues of grains during the evolution of wheat from its wild relatives to the present-day cultivated varieties, and thus suggests the value of detailed physical localization studies in varietal improvement programmes for food crops.