Enhancing Beans (Phaseolus Vulgaris L.) as Sources of Bioavailable Iron through Genetic Selection

Elevated CO2 (eCO2) has been reported to cause mineral losses in several important food crops such as soybean (Glycine max L.) and common bean (Phaseolus vulgaris L.). In addition, more than 30% of the world’s arable land is calcareous, leading to iron (Fe) deficiency chlorosis and lower Fe levels in plant tissues. We hypothesize that there will be combinatorial effects of eCO2 and Fe deficiency on the mineral dynamics of these crops at a morphological, biochemical and physiological level. To test this hypothesis, plants were grown hydroponically under Fe sufficiency (20 μM Fe-EDDHA) or deficiency (0 μM Fe-EDDHA) at ambient CO2 (aCO2, 400 ppm) or eCO2 (800 ppm). Plants of both species exposed to eCO2 and Fe deficiency showed the lowest biomass accumulation and the lowest root: shoot ratio. Soybean at eCO2 had significantly higher chlorophyll levels (81%, p < 0.0001) and common bean had significantly higher photosynthetic rates (60%, p < 0.05) but only under Fe sufficiency. In addition, eCO2 increased ferric chelate reductase acivity (FCR) in Fe-sufficient soybean by 4-fold (p < 0.1) and in Fe-deficient common bean plants by 10-fold (p < 0.0001). In common bean, an interactive effect of both environmental factors was observed, resulting in the lowest root Fe levels. The lowering of Fe accumulation in both crops under eCO2 may be linked to the low root citrate accumulation in these plants when grown with unrestricted Fe supply. No changes were observed for malate in soybean, but in common bean, shoot levels were significantly lower under Fe deficiency (77%, p < 0.05) and Fe sufficiency (98%, p < 0.001). These results suggest that the mechanisms involved in reduced Fe accumulation caused by eCO2 and Fe deficiency may not be independent, and an interaction of these factors may lead to further reduced Fe levels.

Silicon (Si) mitigates the negative effects of iron deficiency in common bean (Phaseolus vulgaris L.) by improving photosystem activities and nutritional status

Iron (Fe) deficiency is a frequent nutritional problem in Florida vegetable crops because of leaching of Fe fertilizer from the soil, poor soil aeration, low soil organic matter (SOM), temperature, high soil pH and/or water bicarbonate content, and interactions with high levels of manganese (Mn) and calcium (Ca). Most Fe-deficient plants are yellow and stunted, with symptoms on younger leaves near the top of the plant because of Fe immobility and poor translocation resulting in interveinal chlorosis. Iron deficiency in tomato ( Solanum lycopersicum ) is characterized by a drastic reduction of leaf chlorophyll content at first at the base of the leaves (bleached leaf) ending in necrotic spots. Iron deficiency can have a significant economic impact depending on the timing of the deficiency during the crop production cycle. Furthermore, crop genotypic variations influence the ability of root systems to acquire Fe. The objective of this article was to describe current methods used by vegetable growers to correct Fe deficiency and to evaluate their effectiveness in tomato, pepper ( Capsicum annuum ), bean ( Phaseolus vulgaris ), and eggplant ( Solanum melongena ) production in Florida. A survey was conducted in the major vegetable production areas in Florida during 2012. Results from the survey indicated that since Fe availability depends on complex soil and environmental factors, there was no reliable soil test method that can predict Fe deficiency on vegetable crops in Florida. Production areas surveyed with calcareous or alkaline soils that are often due to over-liming, Fe becomes unavailable because of significant reduction of Fe. Production practices for those areas were not to use calcitic lime to raise Ca levels, especially if the pH is adequate (6.5). Instead, gypsum or calcium nitrate was recommended for soil Ca. The survey indicated that Fe sulfate (inorganic form) is the most commonly used Fe fertilizer in Florida. However, chelates of Fe were effective but expensive Fe alternative. Among chelate sources, ferric ethylenediaminediaminedi- o -hydroxyphenylacetic acid was frequently the preferred chelate fertilizer for soil application, but it is an expensive option. Soil acidification to lower the soil pH was also used to improve soil Fe availability. Organic matter in animal manures and composts was used as an effective alternative to increase Fe with positive results in Florida tomato production. However, the survey indicated that Fe applied to the soil was converted into unavailable forms especially under high soil pH, thus foliar application was used if Fe deficiency symptoms were observed early in the production cycle.

Phosphoenolpyruvate carboxylase (PEPC) plays an important role in nodules, when there is an increase in the demand for energy. This enzyme provides carbon skeletons to sustain amino acid synthesis and malate to support energy required to fix nitrogen. Since PEPC is important for nodules, and there is lack of information about the effect of some nutrient deficiency in the expression and localization of this enzyme in legume nodules, this work focused on the localization of PEPC in nodules under iron deficiency of two common bean cultivars: Flamingo tolerant and Coco blanc sensitive to iron (Fe) deficiency. The results of immunolocalization using polyclonal antibody showed that this enzyme was detected in all regions of nodule sections; but the signal intensity was increased in Fe-deficient nodules as compared to Fe-sufficient ones in the tolerant cultivar, whereas the intensity was less pronounced in nodules of Fe-deficient plants than in those of Fe-sufficient plants for the sensitive cultivar Coco blanc. This work showed that the symbiotic tolerance of Flamingo to iron deficiency was linked to the increase of PEPC enzymes expression. However, the activity of these enzymes supported the energy required in bacteroids to maintain the nitrogenase activity. Keywords: Common bean, immunolocalization, iron deficiency, nodules, phosphoenol pyruvate carboxylase

Iron (Fe) deficiency is a highly prevalent micronutrient insufficiency predominantly caused by a lack of bioavailable Fe from the diet. The consumption of beans as a major food crop in some populations suffering from Fe deficiency is relatively high. Therefore, our objective was to determine whether a biofortified variety of cream seeded carioca bean (Phaseolus vulgaris L.) could provide more bioavailable-Fe than a standard variety using in-vivo (broiler chicken, Gallus gallus) and in-vitro (Caco-2 cell) models. Studies were conducted under conditions designed to mimic the actual human feeding protocol. Two carioca-beans, a standard (G4825; 58μg Fe/g) and a biofortified (SMC; 106μg Fe/g), were utilized. Diets were formulated to meet the nutrient requirements of Gallus gallus except for Fe (33.7 and 48.7μg Fe/g, standard and biofortified diets, respectively). In-vitro observations indicated that more bioavailable-Fe was present in the biofortified beans and diet (P<0.05). In-vivo, improvements in Fe-status were observed in the biofortified bean treatment, as indicated by the increased total-body-Hemoglobin-Fe, and hepatic Fe-concentration (P<0.05). Also, DMT-1 mRNA-expression was increased in the standard bean treatment (P<0.05), indicating an upregulation of absorption to compensate for less bioavailable-Fe. These results demonstrate that the biofortified beans provided more bioavailable Fe; however, the in vitro results revealed that ferritin formation values were relatively low. Such observations are indicative of the presence of high levels of polyphenols and phytate that inhibit Fe absorption. Indeed, we identified higher levels of phytate and quercetin 3–glucoside in the Fe biofortified bean variety. Our results indicate that the biofortified bean line was able to moderately improve Fe-status, and that concurrent increase in the concentration of phytate and polyphenols in beans may limit the benefit of increased Fe-concentration. Therefore, specific targeting of such compounds during the breeding process may yield improved dietary Fe-bioavailability. Our findings are in agreement with the human efficacy trial that demonstrated that the biofortified carioca beans improved the Fe-status of Rwandan women. We suggest the utilization of these in vitro and in vivo screening tools to guide studies aimed to develop and evaluate biofortified staple food crops. This approach has the potential to more effectively utilize research funds and provides a means to monitor the nutritional quality of the Fe-biofortified crops once released to farmers.

Iron speciation by Mössbauer spectroscopy indicates that ferric iron in an aluminosilicate glass phase is the source of the bioavailable iron in coal fly ash and that this iron species is associated with combustion particles, but not with crustal dust derived from soil minerals. Urban particulate has been shown to be a source of bioavailable iron and has been shown to be able to induce the formation of reactive species in cell culture experiments. Crustal dust and laboratory-generated coal fly ash have been studied as surrogates for two sources of metal-bearing particles in ambient air. As much as a 60-fold difference in the amount of iron mobilized by the chelator citrate was observed between fly ash and crustal dust samples with similar total iron contents. The extent of iron mobilization by citrate in vitro has been shown to correlate with indirect measures of excess iron in cultured cells and with assays for reactive oxygen species generation in vitro. Mössbauer spectroscopy of coal fly ash, before and after treatment with the chelator desferrioxamine B, showed that the iron in an aluminosilicate glass phase was preferentially removed. The removal of the glass-phase iron greatly reduced the amount of iron that could be mobilized by citrate and prevented the particles from inducing interleukin-8 in cultured human lung epithelial (A549) cells. Ferric iron in aluminosilicate glass is associated with particles formed at high temperatures followed by rapid cooling. The observation that ferric iron in aluminosilicate glass is the source of bioavailable iron in coal fly ash suggests that particles from ambient sources and other specific combustion sources should be examined for the presence of this potential source of bioavailable iron.

Iron (Fe) deficiency is one of the most common micronutrient imbalances limiting plant growth globally, especially in arid and saline alkali regions due to the decreased availability of Fe in alkaline soils. Malus halliana grows well in arid regions and is tolerant of Fe deficiency. Here, a physiological and metabolomic approach was used to analyze the short-term molecular response of M. halliana roots to Fe deficiency. On the one hand, physiological data show that the root activity first increased and then decreased with the prolongation of the stress time, but the change trend of root pH was just the opposite. The total Fe content decreased gradually, while the effective Fe decreased at 12 h and increased at 3 d. The activity of iron reductase (FCR) increased with the prolongation of stress. On the other hand, a total of 61, 73, and 45 metabolites were identified by GC-MS in three pairs: R12h (Fe deficiency 12 h) vs. R0h (Fe deficiency 0 h), R3d (Fe deficiency 3 d) vs. R0h, and R3d vs. R12h, respectively. Sucrose, as a source of energy, produces monosaccharides such as glucose by hydrolysis, while glucose accumulates significantly at the first (R12h vs. R0h) and third time points (R3d vs. R0h). Carbohydrates (digalacturonate, L-xylitol, ribitol, D-xylulose, glucose, and glycerol) are degraded into pyruvate through glycolysis and pentose phosphate, which participate in the TCA. Glutathione metabolism and the TCA cycle coordinate with each other, actively respond to Fe deficiency stress, and synthesize secondary metabolites at the same time. This study thoroughly examines the metabolite response to plant iron deficiency, highlighting the crucial roles of sugar metabolism, tricarboxylic acid cycle regulation, and glutathione metabolism in the short-term iron deficiency response of apples. It also lays the groundwork for future research on analyzing iron deficiency tolerance.

Two resistant (Great Northern ‘Emerson’ and Neb-WM1-83-10) and two susceptible (PI 165078 and ‘Steuben Yellow Eye’) cultivars/lines of dry bean (Phaseolus vulgaris L.) to iron (Fe) deficiency chlorosis, and their reciprocal graft combinations (two methods) were grown in pots in Tripp sandy clay loam (coarse-silty, mixed, mesic Aridic Haplustoll) known to induce Fe deficiency chlorosis. Experiments were conducted in a growth chamber under low (24°/13°C) and high (29.5°/18.5°) air temperature regimes at 15/9 hr (light/dark) periods. The experimental plan was a split-plot with temperature regimes as main plot and treatments in a completely randomized design with two replications. When scions of entries susceptible to Fe deficiency were grafted onto rootstocks of resistant entries, the leaves of the grafted plants were greener than the ungrafted susceptible entries. In reciprocal combinations, the leaves of scions of the resistant entries became chlorotic. These data indicate that rootstocks of dry beans appear to control chlorosis resistance, presumably due to root uptake or translocation of Fe. The chlorosis was more severe on leaves of cleft-grafted-scions than with approach-grafted-scions and more severe under the low compared to high temperature regimes.

Iron (Fe) deficiency significantly effects plant growth and development. Plant symptoms under excess zinc (Zn) resemble symptoms of Fe-deficient plants. To understand cross-talk between excess Zn and Fe deficiency, we investigated physiological parameters of Arabidopsis plants and applied iTRAQ-OFFGEL quantitative proteomic approach to examine protein expression changes in microsomal fraction from Arabidopsis shoots under those physiological conditions. Arabidopsis plants manifested shoot inhibition and chlorosis symptoms when grown on Fe-deficient media compared to basal MGRL solid medium. iTRAQ-OFFGEL approach identified 909 differentially expressed proteins common to all three biological replicates; the majority were transporters or proteins involved in photosynthesis, and ribosomal proteins. Interestingly, protein expression changes between excess Zn and Fe deficiency showed similar pattern. Further, the changes due to excess Zn were dramatically restored by the addition of Fe. To obtain biological insight into Zn and Fe cross-talk, we focused on transporters, where STP4 and STP13 sugar transporters were predominantly expressed and responsive to Fe-deficient conditions. Plants grown on Fe-deficient conditions showed significantly increased level of sugars. These results suggest that Fe deficiency might lead to the disruption of sugar synthesis and utilization.

The effects of salicylic acid (SA) on alleviating chlorosis induced by iron (Fe) deficiency in peanut seedlings (Arachis hypogaea L.) were studied by investigating the symptoms, plant growth, chlorophyll concentrations, soluble Fe concentration, Fe distribution in subcellular, and antioxidant enzymes. Fe deficiency caused serious chlorosis and inhibited growth of peanut seedlings, and dramatically decreased the soluble Fe concentration and chlorophyll concentration. Furthermore, ion balance was disturbed. The addition of 50, 100, and 250 μM SA significantly increased the absorption of Fe from the cell wall to cell organelles and the soluble fraction, enhanced the Fe concentration in cell organelles, Fe activation and chlorophyll concentrations in leaves, ameliorated the inhibition of Ca, Mg, and Zn absorption induced by Fe deficiency, alleviated the chlorosis induced by Fe deficiency and promoted plant growth. The accumulation of reactive oxygen species (ROS) is dramatically increased in peanut seedlings exposed to Fe deficiency, and resulted in lipid peroxidation, which was indicated by accumulation of malondialdehyde (MDA). The application of 50, 100, and 250 μM SA significantly decreased the level of ROS and MDA concentrations, and significantly increased the activities of superoxide dismutase, peroxidase, and catalase in peanut seedlings exposed to Fe deficiency. The addition of 100 μM SA had the best effect on alleviating chlorosis induced by Fe deficiency, whereas the addition of 500 μM SA had no significant effect under Fe deficiency.

The pathophysiology of glossal pain in patients with iron deficiency and anemia.

BackgroundRice (Oryza sativa L.) is highly susceptible to iron (Fe) deficiency due to low secretion levels of the mugineic acid (MA) family phytosiderophore (PS) 2′-deoxymugineic acid (DMA) into the rhizosphere. The low levels of DMA secreted by rice have proved challenging to measure and, therefore, the pattern of DMA secretion under Fe deficiency has been less extensively studied relative to other graminaceous monocot species that secrete high levels of PS, such as barley (Hordeum vulgare L.).ResultsGene expression and metabolite analyses were used to characterise diurnal changes occurring during the Fe deficiency response of rice. Iron deficiency inducible genes involved in root DMA biosynthesis and secretion followed a diurnal pattern with peak induction occurring 3–5 h after the onset of light; a result consistent with that of other Strategy II plant species such as barley and wheat. Furthermore, triple quadrupole mass spectrometry identified 3–5 h after the onset of light as peak time of DMA secretion from Fe-deficient rice roots. Metabolite profiling identified accumulation of amines associated with metal chelation, metal translocation and plant oxidative stress responses occurring with peak induction 10–12 h after the onset of light.ConclusionThe results of this study confirmed that rice shares a similar peak time of Fe deficiency associated induction of DMA secretion compared to other Strategy II plant species but has less prominent daily fluctuations of DMA secretion. It also revealed metabolic changes associated with the remediation of Fe deficiency and mitigation of damage from resulting stress in rice roots. This study complements previous studies on the genetic changes in response to Fe deficiency in rice and constitutes an important advance towards our understanding of the molecular mechanisms underlying the rice Fe deficiency response.

The Pathophysiology of Glossal Pain in Patients with Iron Deficiency and Anemia

The present study demonstrates that chlorophyll biosynthesis can be effectively used for identifying iron (Fe) deficiency tolerant cultivars from a large population. Fifty genetically diverse wheat cultivars were screened on the basis of the leaf greenness index, i.e. chlorophyll retention under iron deficient (Fe−) compared to iron sufficient (Fe+) conditions, and three Fe deficiency tolerant and two Fe deficiency susceptible cultivars were identified. These two groups of cultivars were further tested for their efficiency for Fe uptake and translocation and biomass production per unit Fe under Fe deficient condition in the nutrient solution culture. Fe deficiency tolerant lines were found capable of translocating more Fe to the shoot and produced greater biomass per unit of Fe when compared with the susceptible group. Efficiency for chlorophyll biosynthesis per unit shoot Fe was also higher for the tolerant group of cultivars. Fe use efficient cultivars produced and released a larger amount of phytosiderophore (PS) and differed from the inefficient cultivars in terms of the PS release but not in the PS biosynthesis. Thus, indicating that the limitation at the level of release of the PS was responsible for low Fe use efficiency of the Fe deficiency susceptible cultivars. Further the diurnal variation in the PS release was similar for all the investigated wheat cultivars and did not influence the genotypic variation in the Fe use efficiency.

Anémies ferriprives et/ou inflammatoires