Higher Fe Uptake Research Articles

Enhancing iron bioavailability in lentil grains circumventing the phytate barrier

The study aimed at examining the effect of Iron (Fe) management strategies on the redistribution of Fe fractions in soil and on the Fe bioavailability and phytic acid (PA) content in lentil grains. A pot experiment was conducted in Completely Randomized Design with 8 treatments replicated thrice. The treatments were Control (no fertilizer); Recommended dose of fertilizers (RDF) i.e. 20:40 (N: P2O5); RDF + Fe (basal application @10 kg/ha); RDF + Fe (foliar@ 1% (w/v) solution); RDF + Fe (basal + foliar); RDF + FeSB (biopriming with Fe solubilizing bacteria (Enterobacter cloacae strain BAU3) @ 5 mL/kg seed (1 x109 cfu mL−1)); RDF + Fe (seed nutripriming with 1% (w/v) solution); and RDF + (biopriming + nutripriming). Fe source for the treatments was Fe-EDDHA chelate. Higher Fe release from these fractions was observed under biopriming + nutripriming with water soluble Fe of 21.09 and 20.82 mg kg−1, respectively for the biopriming + nutripriming and sole biopriming treatments; and organically bound Fe of 230.95 and 211.36 mg kg−1 for the same treatments. These fractions contributed toward higher Fe uptake which was highest under biopriming + nutripriming. Values were statistically significant for biopriming and nutripriming and basal + foliar treatment. Lowest PA values in lentil grains as well as PA/Fe ratio were estimated under basal + foliar and biopriming + nutripriming treatments. Combined basal and foliar application of Fe esp. in chelated form and use of seed priming strategies have immense potential in enhancing the Fe bioavailability in grains from soil, seed or foliage.

Effect of hydroxamate and catecholate siderophores on iron availability in the diatom Skeletonema costatum: Implications of siderophore degradation by associated bacteria

The bioavailability of iron (Fe) across marine ecosystems, mainly determined by Fe speciation and species-specific requirements of phytoplankton, remains largely unresolved. Siderophores are relevant within the pool of organic ligands that control organic Fe speciation. The effect on growth and physiology of the diatom Skeletonema costatum following addition over time of the uncomplexed siderophores (apo-form) desferrioxamine B and enterobactin were studied in the laboratory. The diatom was grown in batch culture in concentration gradients up to 50 and 10,000 nM for enterobactin and desferrioxamine B respectively. The potential effect of siderophore degradation was analyzed by electrospray ionization mass spectroscopy (HPLC-ESI-MS). Growth of S. costatum was negatively correlated to desferrioxamine concentration. In treatments where >500 nM was added, growth was negligible until day 9 after which significant growth started. Fe uptake at day 9 was highest at 10,000 nM, while the Fe quota was the lowest. The addition of enterobactin had a negative effect on the abundance, the in-vivo fluorescence and the Fe quota in S. costatum only at the highest concentration of 50 nM, while the in-vivo fluorescence was enhanced at the lowest concentration. The bacterial abundance over time was also negatively correlated to the concentration for both siderophores, but at day 9 the bacterial uptake showed an increase proportional to the siderophore concentration. HPLC-ESI-MS analysis revealed the presence of tentative metabolites of desferrioxamine in 500 and 10,000 nM indicating changes in concentration of the apo-siderophore. In the presence of cathecolate and hydroxamate siderophores, S. costatum exhibited the capacity for different Fe uptake strategies. The late growth exhibited and the high Fe uptake after prolonged Fe-limited growth, suggests that Fe reduction at cell's membrane may be facilitated by possible degradation of desferrioxamine by the associated bacteria. The results emphasize the need for studying Fe bioavailability of algae together with the interacting bacterial community.

The Crotalaria juncea metal transporter CjNRAMP1 has a high Fe uptake activity, even in an environment with high Cd contamination

Large quantities of Fe and Cd accumulate in the leaves of the metal-accumulating leguminous plant, Crotalaria juncea. A member of the metal transporter NRAMP family was cloned from C. juncea. The amino acid sequence of this clone, designated CjNRAMP1, was similar to the sequence of Arabidopsis AtNRAMP1, which is involved in Fe and Cd transport. Organ-specific analysis showed that CjNRAMP1 mRNA was expressed mainly in the leaves of C. juncea plants, as well as in stems and roots. Use of green fluorescent protein fused to CjNRAMP1 suggested its localization to the plasma membranes of plant cells. Complementation experiments using yeast strains with impaired metal transport systems showed that CjNRAMP1 transported both Fe and Cd in an inward direction within the cells. Transgenic Arabidopsis plants overexpressing CjNRAMP1 showed high tolerance to Cd, with Cd translocation from roots to leaves being substantially greater in transgenic than in wild-type plants. Overexpression of CjNRAMP1 resulted in a greater accumulation of Fe in shoots and roots, suggesting that CjNRAMP1 recognizes Fe and Cd as substrates and that the high Cd tolerance of CjNRAMP1 is due to its strong Fe uptake activity, even in the presence of high Cd concentrations in the rhizosphere.

The Restriction of Individual Performance of PGPR on Maize Nutrient Uptake by Antagonistic Relations

Abstract Recent studies have shown that certain soil microorganisms are capable to sustain plant nutrition in both conventional and organic agriculture; however, yet further studies needed for evaluation of the factors affecting PGPR performance. The goal of this research was to evaluate performance of natural bacteria relative to nutrient uptake and biomass development in corn (Zea mays L.) as it is related to conventional production systems. Soils have been collected from forested areas of Lake Region. The isolated bacteria have been tested at the conventional farm in Mediterranean region. Nine isolated and one cocktailed bacteria suspensions have been applied to rhizosphere of corn plants under regular cultivation practices in conventional production systems. The results revealed that all isolates are showing either positive or negative effect on both plant performance and nutrient uptake. No statistical differences were observed on grain yield; however, Isolates 3 and 9 showed improved grain-excluded biomass performances by 37.1% and 38.5% respectively. Phosphorus, zinc and manganese uptakes were the highest in Isolate 6 whereas the highest Fe uptake was determined in Isolate 8 at the tuft formation stage. Although all isolates represent their specific individual performances as far as any plant nutrient uptakes are concerned, their cocktail was not as effective. That happened probably due to competition between the isolates.

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.

Glycosaminoglycans isolated from fish muscle enhance iron uptake by Caco‐2 cells

Numerous attempts have been made to identify the factor in muscle tissue that enhances Fe absorption but the nature of the promoter remains controversial. Previous research suggested that sulfated glycosaminoglycans (GAGs) from fish muscle promote Fe uptake in Caco‐2 cells (1). This study continues that research to confirm that GAGs enhance Fe uptake by Caco‐2 cells.Fish haddock filets were cooked and lyophilized. GAGs were isolated and separated into low and high sulfur fractions (2). Enzymatic digestion with chondroitinase ABC (50 mU/mg, 1h, 37ºC) and reverse phase chromatography (RP‐HPLC) were used to characterize the GAGs. Nonheme Fe was added to the isolated fractions and to whole cooked fish and an in vitro digestion/Caco‐2 cell model was used to assess their effect on Fe uptake (1).RP‐HPLC analyses showed that retention times of the main components in the high sulfur fraction were consistent with chondroitin/dermatan sulfate‐related structures. This fraction increased Fe uptake up to 185% relative to controls exposed to nonheme Fe. Treatment of the isolated fraction with chondroitinase eliminated the enhancing effect. Unfractioned fish caused a 40% higher Fe uptake than caused by GAG isolates.These results indicate that specific GAGs contribute to the enhancing effect of fish on Fe uptake by Caco‐2 cells but that other factors are also involved.

Interactions Between High pH and Iron Supply on Nodulation and Iron Nutrition of Lupinus albus L. Genotypes Differing in Sensitivity to Iron Deficiency

Poor growth of white lupin (Lupinus albus L.) on alkaline soils may result from its sensitivity to iron deficiency and poor nodulation. This study examined interactive effects of iron supply and high pH on the growth and nodulation of three genotypes differing in their sensitivity to iron deficiency. Three genotypes (P27486, Ultra and WTD180) were grown for 17 days in buffered solutions with Fe supply of 0.2, 2 and 20 μM. Solution pH was adjusted to 5.2, 6.5 or 7.5. Plant growth, nodulation and nutrient concentrations in plants were measured. Decreasing Fe supply decreased chlorophyll concentration in young leaves by up to 92%. Increasing pH decreased chlorophyll concentration by an average of 40% at pH 6.5 and by 47% at pH 7.5. The decrease of chlorophyll was less obvious in P27485 than in Ultra or WTD180. Shoot biomass was reduced by up to 18% by Fe deficiency, with such decrease being less for P27486. Increasing pH exacerbated the effect of Fe deficiency on shoot biomass only of Ultra. Decreasing Fe supply decreased nodule number by an average of 54%, and increasing pH decreased nodule number by 80%. P27486 formed the greatest number of nodules while WTD180 the least. P27486 had high Fe uptake and low internal requirement. Irrespective of genotype, leaf chlorosis positively correlated with cluster root formation. The results suggest that a combination of Fe deficiency and high pH impaired nodulation in L. albus, and that selection of genotypes for both tolerance of iron deficiency and good nodulation at high pH is important for a successful lupin crop on alkaline soils.

Studies on impact of phosphoenriched compost, chemical fertilizer and method of zinc application on yield, uptake and quality of maize (Zea mays)

A field experiment was conducted during the rainy (kharif) seasons of 2012 and 2013 at New Delhi to examine the effect of phosphorus (P) sources and zinc (Zn) application on yield, uptake and quality of maize (Zea mays L.). Application of P -phosphoenriched compost (PEC) + P -fertilizer (F) recorded higher yield attributes, grain yield 50 50 (4.3 t/ha) and protein (9.2%) with amino acids content in grain. The P50- PEC + P50- F recorded higher P, Zn and Fe uptake in grain, stover and total (grain + stover) than the control. The application of 12.5 kg/ha of ZnSO + 1 fo- 4 liar spray of ZnSO @ 0.5% recorded the highest values of yield attributes and grain yield (4.2 t/ha) of maize. The 4 P and Zn uptake in grain and stover were found highest in soil + foliar-applied plots. The higher Fe uptake in grain was found with 2 foliar sprays of Zn. The higher crude protein (9%) and amino acids were found in 25 kg/ha of ZnSO and it was on a par with soil + foliar application of Zn. Overall, combined application of PEC and chemical 4 fertilizer with soil + foliar application of Zn proved promising in for higher yield with increased tissue uptake of nu- trients and for higher protein and amino acids content in grain.

ZINC AND MOLYBDENUM ON YIELD AND NUTRITION OF SOYBEAN

Soybean Co.I. raised on Perianaickanpalayam (Typic ustivertept) and Irugur (Typic ustorthent) soil series at Tamil Nadu Agricultural University Farm, Coimbatore during rabi 1990-91 and kharif 1991-92 respectively responded significantly to Zn fertilizetion at 5.0 kg ha". Combined application of Zn, Mo and FYM at 2.5 kg, 0.5 kg and 10t ha' respectively produced the highest seed yield in both the years besides increasing their content and uptake by soybean seed. The highest Fe uptake by seed during rabi 1990-91 was evidenced with the application of 5.0 kg Zn ha".

ZINC AND MOLYBDENUM ON YIELD AND NUTRITION OF SOYBEAN

Soybean Co.l. raised on Perianaickanpalayam (Typic ustivertept) and Irugur (Typic ustorthent) soil scries at Tamil Nadu Agricultural University Farm, Coimbatore during rabi 1990-91 and kharif 1991-92 respectively responded significantly to Zn fertilizetion at 5.0 kg ha. Combined application of Zn, Mo and FYM at 2.5 kg, 0.5 kg and 10 t ha respectively produced the highest seed yield in both the years besides increasing their content and uptake by soybean seed. The highest Fe uptake by seed during rabi 1990-91 was evidenced with the application of 5.0 kg Zn ha".

Studies on Fe complexes produced by yeast. IV. Mechanism of Fe transport from an Fe(II)-oligosaccharide complex across the mucosal membrane of the rat intestine.

The mechanism of Fe transport across the rat duodenal membrane from an Fe(II)-oligosaccharide complex (designated B1-c) produced in wine by yeast and showing high hematopoietic activity in rats was examined. The Fe uptake from B1-c by brush border membrane (BBM) vesicles isolated from the rat intestine was based mainly on the Fe binding to membrane components which were suggested to be inside the vesicles. Evidence that Fe was transported into the vesicles by a special transport system other than simple diffusion was obtained by observing saturation kinetics under conditions of isotope exchange, and temperature and pH dependence. This Fe uptake was not inhibited by any metal ions tested, including inorganic Fe(II), and the BBM vesicles from the duodenum had a higher Fe uptake than those from the other parts of the small intestine. Furthermore, the BBM vesicles isolated from rats with Fe deficiency showed a significantly increased Fe uptake. The Km value for B1-c uptake was 0.16 mM, lower than the values for FeSO4 and ferrous ascorbate. These results suggest that a special transport system selective for B1-c may be present on the mucosal membrane. B1-c was taken up by the BBM vesicles in the form of Fe-oligosaccharide complex. From the preloaded vesicles, B1-c was released temperature- and pH-dependently.(ABSTRACT TRUNCATED AT 250 WORDS)