Iron Biofortification Research Articles

Iron Biofortification of Greenhouse Soilless Lettuce: An Effective Agronomic Tool to Improve the Dietary Mineral Intake

The present experiment addressed the effects of different iron (Fe) concentrations in the nutrient solution supplied as Fe-HBED, i.e., 0.02 (Fe0, control), 1.02 (Fe1), and 2.02 mmol L−1 (Fe2) on lettuce (‘Nauplus’ and ‘Romana’) yield and compositional traits. This experiment was carried out in a greenhouse using an open soilless cultivation system, at the experimental farm of the University of Catania (Sicily, Italy: 37°24′31.5″ N, 15°03′32.8″ E, 6 m a.s.l.). The addition of Fe-HBED reduced the plants’ aboveground biomass (−18%, averaged over Fe1 and Fe2), but promoted their dry matter content (+16% in Fe2). The concentration of chlorophylls, carotenoids, anthocyanins, and antioxidants peaked at Fe2, along with the antioxidant capacity and concentration of stress indicators in leaves. The Fe content in leaves was promoted in the Fe-treated plants (+187% averaged over Fe1 and Fe2). ‘Romana’ showed the highest Fe accumulation (reaching 29.8 mg kg−1 FW in Fe1), but ‘Nauplus’ proved a higher tolerance to the Fe-derived oxidative stress. The Fe2 treatment maximized leaf N, P, K, S, and Zn contents, while those of Ca, Mg, Mn, and B peaked at Fe1. Overall, our study revealed the effectiveness of Fe-HBED in increasing the Fe content and improving the nutritional quality of lettuce grown in soilless cultivation systems.

Iron Biofortification of Wheat Grains by Foliar Application of Nano Zero-valent Iron (nZVI) and Other Iron Sources with Urea

Iron Biofortification of Wheat Grains by Foliar Application of Nano Zero-valent Iron (nZVI) and Other Iron Sources with Urea

Genome-Wide Association Mapping Identifies Key Genomic Regions for Grain Zinc and Iron Biofortification in Bread Wheat.

Accelerating breeding efforts for developing biofortified bread wheat varieties necessitates understanding the genetic control of grain zinc concentration (GZnC) and grain iron concentration (GFeC). Hence, the major objective of this study was to perform genome-wide association mapping to identify consistently significant genotyping-by-sequencing markers associated with GZnC and GFeC using a large panel of 5,585 breeding lines from the International Maize and Wheat Improvement Center. These lines were grown between 2018 and 2021 in an optimally irrigated environment at Obregon, Mexico, while some of them were also grown in a water-limiting drought-stressed environment and a space-limiting small plot environment and evaluated for GZnC and GFeC. The lines showed a large and continuous variation for GZnC ranging from 27 to 74.5 ppm and GFeC ranging from 27 to 53.4 ppm. We performed 742,113 marker-traits association tests in 73 datasets and identified 141 markers consistently associated with GZnC and GFeC in three or more datasets, which were located on all wheat chromosomes except 3A and 7D. Among them, 29 markers were associated with both GZnC and GFeC, indicating a shared genetic basis for these micronutrients and the possibility of simultaneously improving both. In addition, several significant GZnC and GFeC associated markers were common across the irrigated, water-limiting drought-stressed, and space-limiting small plots environments, thereby indicating the feasibility of indirect selection for these micronutrients in either of these environments. Moreover, the many significant markers identified had minor effects on GZnC and GFeC, suggesting a quantitative genetic control of these traits. Our findings provide important insights into the complex genetic basis of GZnC and GFeC in bread wheat while implying limited prospects for marker-assisted selection and the need for using genomic selection.

Organ-specific expression of genes involved in iron homeostasis in wheat mutant lines with increased grain iron and zinc content.

BackgroundIron deficiency is a well-known nutritional disorder, and the imbalance of trace-elements, specifically iron, is the most common nutrient deficiency of foods across the world, including in Kazakhstan. Wheat has significant nutritional relevance, especially in the provision of iron, however many bread wheat varieties have low iron despite the need for human nourishment. In this study, the expression profiles of wheat homologous genes related to iron homeostasis were investigated. The work resulted in the development of two new M5 mutant lines of spring bread wheat through gamma-irradiation (200 Gy) with higher grain iron and zinc content, lower phytic acid content, and enhanced iron bioavailability compared to the parent variety. Mutant lines were also characterized by higher means of yield associated traits such as grain number per main spike, grain weight per main spike, grain weight per plant, and thousand-grain weight.MethodsThe homologous genes of bread wheat from several groups were selected for gene expression studies exploring the tight control of iron uptake, translocation rate and accumulation in leaves and roots, and comprised the following: (1) S-adenosylmethionine synthase (SAMS), nicotianamine synthase (NAS1), nicotianamine aminotransferase (NAAT), deoxymugineic acid synthetase (DMAS), involved in the synthesis and release of phytosiderophores; (2) transcription factor basic helix-loop-helix (bHLH); (3) transporters of mugineic acid (TOM), involved in long-distance iron transport; (4) yellow stripe-like (YSlA), and the vacuolar transporter (VIT2), involved in intracellular iron transport and storage; and lastly (5) natural resistance-associated macrophage protein (NRAMP) and ferritin (Fer1A).ResultsThe wheat homologous genes TaSAMS, TaNAS1, and TaDMAS, were significantly up-regulated in the roots of both mutant lines by 2.1–4.7-fold compared to the parent variety. The combined over-expression of TaYSlA and TaVIT2 was also revealed in the roots of mutant lines by 1.3–2.7-fold. In one of the mutant lines, genes encoding intracellular iron transport and storage genes TaNRAMP and TaFer1A-D showed significant up-regulation in roots and leaves (by 1.4- and 3.5-fold, respectively). The highest expression was recorded in the transcription factor TabHLH, which was expressed 13.1- and 30.2-fold in the roots of mutant lines. Our research revealed that genotype-dependent and organ-specific gene expression profiles can provide new insights into iron uptake, translocation rate, storage, and regulation in wheat which aid the prioritization of gene targets for iron biofortification and bioavailability.

Biofortification of iron and zinc in rice and wheat.

Iron and zinc are critical micronutrients for human health. Approximately two billion people suffer from iron and zinc deficiencies worldwide, most of whom rely on rice (Oryza sativa) and wheat (Triticum aestivum) as staple foods. Therefore, biofortifying rice and wheat with iron and zinc is an important and economical approach to ameliorate these nutritional deficiencies. In this review, we provide a brief introduction to iron and zinc uptake, translocation, storage, and signaling pathways in rice and wheat. We then discuss current progress in efforts to biofortify rice and wheat with iron and zinc. Finally, we provide future perspectives for the biofortification of rice and wheat with iron and zinc.

Novel rice iron biofortification approaches using expression of ZmYS1 and OsTOM1 controlled by tissue-specific promoters.

Intrinsic improvement of iron (Fe) concentration in rice grains, called rice Fe biofortification, is a promising countermeasure against widespread human Fe deficiency. In this study, two novel rice Fe biofortification approaches are reported. The first approach (Y approach) involved the expression of maize YELLOW STRIPE 1 controlled by the HEAVY METAL ATPASE 2 promoter. The Y approach increased the polished grain Fe concentrations up to 4.8-fold compared with the non-transgenic (NT) line. The second approach (T approach) involved the expression of rice TRANSPORTER OF MUGINEIC ACID 1 controlled by the FERRIC REDUCTASE DEFECTIVE LIKE 1 promoter. The T approach increased the polished grain Fe concentrations by up to 3.2-fold. No synergistic increases in the polished grain Fe concentrations were observed when Y and T approaches were combined (YT approach). However, the polished grain Fe concentrations further increased by 5.1- to 9.3-fold compared with the NT line, when YT approach was combined with the endosperm-specific expression of FERRITIN (YTF approach), or when YTF approach was combined with the constitutive expression of NICOTIANAMINE SYNTHASE (YTFN approach). Total grain weight per plant in most Y, T, YT, and YTFN lines was comparable to that in the NT line, while it was significantly decreased in most YTF lines. The novel approaches reported in this study expand the portfolio of genetic engineering strategies that can be used for Fe biofortification in rice.

Symbiotic interplay of Piriformospora indica and Azotobacter chroococcum augments crop productivity and biofortification of Zinc and Iron

In the present study Piriformospora indica (Pi) a phyto-promotional fungus and Azotobacter chroococcumWR5 (AzWR5) a rhizobacterium, were symbiotically evaluated for their role in improving the nutritional quality of wheat (Triticum aestivum L.). Co-inoculation of Pi+AzWR5 modified root system architecture of host and along with increasing the proportion of finer roots by 88% and 92% in C306 and Hd2967 respectively. Furthermore, the synergistic impact of Pi+AzWR5 interplayed for enhanced accumulation of Zn and Fe in different plant parts including grains (3.12 and 1.33 fold respectively). Pi+AzWR5 increased the transfer factor of Zn (62%, 94%, 91% and 213%) and Fe (31%, 54%, 68% and 32%) in root, stem, leaves and grains, respectively, and translocation factor of Zn (20%, 18% and 63%) and Fe (18%, 29% and 29%) for root-stem, root-leaves and root-grains, respectively. In addition to these co-inoculation of endophytes led to several fold increase in expression of four ZIP transporter genes in roots and shoot. In addition to these symbiotic association of endophytes with host led to 3 fold increase in grain yield. We thereby conclude that co-inoculation of Pi+AzWR5 substantially improves mobilization of Zn and Fe from soil and increase its concentration in grains as well as improves crop yield.

Agronomic Biofortification of Zinc and Iron on Yield Potential and Zinc Fortification in Chickpea (Cicer arietinum L.) Varieties under Arid Western Plains Zone of Rajasthan

Background: According to the World Health Organization on worldwide prevalence of micronutrient deficiencies, zinc deficiency ranked 11th amongst twenty most important factors in the world, whereas zinc and iron deficiency ranks 5th and 6th respectively, amongst ten most important factors in developing countries. Among micronutrients, zinc (Zn) and iron (Fe) deficiency in human nutrition are wide spread in Asian developing countries including India. Therefore, agronomic biofortification is easiest and immediate effective method for enriching seed with zinc and iron, which could relieve malnutrition issues in developing countries, particularly in India. Methods: A field trial was carried out to study the agronomic biofortification of zinc and iron in chickpea (Cicer arietinum L.) varieties under Arid Western Plains Zone of Rajasthan. Growing of two varieties namely GNG-1581 and RSG-974 and seven fortification treatments included various doses of zinc and iron were assigned under FRBD and trial was carried out at Instructional Farm, College of Agriculture, Jodhpur (Rajasthan) during rabi season of 2019-20. Result: The results revealed that significantly higher yield attributes and yield viz. pods plant-1 and 100-grain weight were produced under the RSG-974, while higher number of seeds pod-1 as well as seed, stover and biomass yield along with higher zinc contents and their uptakes were noticed in chickpea variety GNG-1581 under application of ZnSO4 @ 25 kg ha-1 (SA) + 0.5% FeSO4 (FA).

Zinc and iron biofortification in pearl millet cultivars as influenced by different fertifortification strategies in semi arid tropics

Two field experiments were conducted during Kharif 2018 and 2019 on clay loam soils at Zonal Agricultural and Horticultural Research Station, Babbur farm, Hiriyur, Karnataka to evaluate the performance of pearl millet cultivars by different zinc (Zn) and iron (Fe) fertifortification methods. Micronutrient (Zn and Fe) management strategies were employed in main plots that include application of recommended NPK, along with recommended NPK supply of Fe and Zn through soil, foliar application and FYM enrichment along with plant growth promoting rhizobacteria (PGPR). Three pearl millet cultivars [Variety - ICTP 8203 Fe (Dhanshakti), Hybrid - ICMH 1202 and local cultivar (variety - WCC 75)] were considered in sub plots laid in split plot design with three replications. Three methods of micronutrient application tested improved the grain Fe and Zn concentrations of both biofortified cultivars Dhanshakti and Hybrid along with grain yield. Enrichment of FYM with Fe and Zn resulted in higher concentration and uptake of Fe and Zn than other modes of micronutrient application. The hybrid ICMH 1202 had obtained significantly higher grain yield (2203 kg ha−1), grain micronutrient concentration of pearl millet (50.52 and 83.88 mg kg−1 Zn and Fe, respectively) with the application of enriched FYM + PGPR along with recommended NPK and found the best.

Iron biofortification potential of siderophore producing rhizobacterial strains for improving growth, yield and iron contents of groundnut

Biofortification in crops is an effective and sustainable approach to reduce global malnutrition. Groundnut (Arachis hypogea L.) is inherently low in micronutrients, especially iron. A greenhouse study was conducted to evaluate the effect of siderophore producing bacterial strains (SPBs) on growth, yield and iron content of groundnut. Three efficient SPBs identified as Bacillus subtilis and their consortia were used alone and with soil or foliar applied iron. The results revealed that the inoculation of SPBs alone and combination with soil applied Fe, showed maximum relative increase of 63 and 86 percent in shoot fresh and dry weight respectively. Likewise, the number of pods plant−1, pod weight plant−1, 20 pod length and 100 kernel weight of groundnut were increased significantly in response to sole application SPBs and their combinations with soil applied (SA) or foliar applied (FA) iron. Moreover, nutrient (N, P, K, Zn & Fe) concentrations in kernel and straw were also showed significant differences in all treatments. Findings further revealed that the combined application of SPBs + Fe-SA increased total Fe-uptake of groundnut between 24.14 to 49.75 percent while for SPBs + Fe-FA treatment this increase varied between 14.73 to 45.72 percent (over to the SPBs alone) The overall results indicated that SPBs have the potential to increase growth, yield and nutrient contents of groundnut which advocate that microbial-mediated Fe biofortification of groundnut could be a promising strategy to ameliorate Fe deficiency-induced disordering in human beings especially in developing countries.

Impact of Inorganic Iron and Siderophore Producing Microbes on Growth and Content of Nutrient in Indian Sorrel Leaves (Rumex vasicarias)

A pot culture experiment entitled “Biofortification of Iron in Indian Sorel Leaves using Graded Levels of Iron and Siderophore Producing Microbial Cultures” was planned and conducted during summer season of 2021 at Department of soil science and Agricultural Chemistry, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani. The experimental results revealed that significant higher values of biometric observation in 45, 55 DAS and nutrient content a nd uptake in sorrel leaves at after harvest of crop were recorded. The maximum value regarding growth attributes as well as quality parameter was recorded under the treatment of 100% RDF + 60 mg FeSO4 kg-1 soil + Azospirillum lipoferum. In which maximum plant height recorded with 23.14, and 29.44cm, leaves number (10.50 and 21.92) at 45 and 55 DAS respectively, chlorophyll 3.42 mg g-1, fresh leaf yield and dry matter yield (214.33, 30.87 g pot-1) respectively which were superior among the rest of treatments. Moreover, regarding to quality attributes of sorrel leaves via. macro and micronutrient uptake significantly higher under the treatment of 100% RDF + 60 mg FeSO4 kg-1 soil + Azospirillum lipoferum as compared to control (only RDF).

Selenium Resistant Bacilli and Pseudomonas as Potential Candidate for Selenium and Iron Biofortification in Maize Plants

Selenium is an essential element and is required in minute quantities for performing vital functions in living cells. Food is the ultimate source of selenium for animal and human populations. Crops, such as maize, which are used as food and feed, can be biofortified with selenium to alleviate selenium deficiency in both populations. The current study was conducted to isolate selenium-resistant bacteria from soil samples. Isolated bacteria were characterized on a morphological and biochemical basis. For specie level classification, 16S rRNA sequences were obtained. Isolated strains belonged to Bacillus halotolerans (TM3),Pseudomonas protegens (TM5), and Bacillus endophyticus (TM7). In-vitro PGPB characterization showed that some of the strains can produce IAA, Ammonia, HCN, and phosphate solubilization enzymes. Greenhouse pot experiments showed that the isolates enhanced seed germination rate, shoot length, and plant dry weight. Selenium supplementation caused decreased growth, but its effect was mitigated by the inoculation of isolated bacteria. Inoculation of these bacteria enhanced selenium content in maize leaves and shoots, ranging from 6-7%, while the addition of selenium to the soil increased selenium content by 300%. The iron content of maize leaves was also increased up to 17% in the inoculated strains.

Iron biofortification of broccoli microgreens under different radiation spectrum and composition of nutrient solution

Iron biofortification of broccoli microgreens under different radiation spectrum and composition of nutrient solution

Thiobacillus Bacteria-Enhanced Iron Biofortification of Soybean in a Calcareous Soil Enriched with Ferrous Sulfate, Mill Scale, and Pyrite

Thiobacillus Bacteria-Enhanced Iron Biofortification of Soybean in a Calcareous Soil Enriched with Ferrous Sulfate, Mill Scale, and Pyrite

The Role of Membrane Transporters in the Biofortification of Zinc and Iron in Plants.

Over three billion people suffer from various health issues due to the low supply of zinc (Zn) and iron (Fe) in their food. Low supply of micronutrients is the main cause of malnutrition and biofortification could help to solve this issue. Understanding the molecular mechanisms of biofortification is challenging. The membrane transporters are involved in the uptake, transport, storage, and redistribution of Zn and Fe in plants. These transporters are also involved in biofortification and help to load the Zn and Fe into the endosperm of the seeds. Very little knowledge is available on the role and functions of membrane transporters involved in seed biofortification. Understanding the mechanism and role of membrane transporters could be helpful to improve biofortification. In this review, we provide the details on membrane transporters involved in the uptake, transport, storage, and redistribution of Zn and Fe. We also discuss available information on transporters involved in seed biofortification. This review will help plant breeders and molecular biologists understand the importance and implications of membrane transporters for seed biofortification.

Iron bio-fortification and heavy metal/(loid)s contamination in cereals: successes, issues, and challenges

Biofortification of micronutrients, particularly of the iron (Fe) in cereals, is a viable, attractive, and sustainable strategy to cope with malnutrition as cereals are the major staple diets, particularly in developing countries. Increased concentrations of heavy metal/(loid)s (HMs); i.e. cadmium (Cd), lead (Pb), arsenic (As) etc. in agricultural soils is an increasing and serious challenge, posing severe health problems through food chain contamination. Accumulation of HMs in plants is challenging and contrasts to the development of biofortification strategies to combat micronutrient deficiencies. Agricultural biofortification strategies aim to increase plant uptake of mineral nutrients from soil and the translocation/storage of micronutrients to edible portions of cereal grains. However, it also means that any strategy to increase the uptake of Fe in plants may result in increased uptake of other toxic HMs. Therefore, the issue of HM contamination in cereals needs further understanding. This review describes the advancements in Fe biofortification strategies and the conflicting issue of HM accumulation in the grain of cereals.

Iron biofortification through genetic modification in rice, wheat, and cassava and its potential contribution to nutritional security

Abstract Micronutrient malnutrition is one of the major concerns noted in the United Nations Sustainable Development Goals. In developing countries, children under the age of five and pregnant women are at the highest risk of adverse events from micronutrient malnutrition. Staple food crops that are common in developing countries are rich in carbohydrates but low in micronutrients, especially iron. Genetic biofortification of staple food crops in farmer-preferred cultivars is a promising approach to deliver nutritious food, enhanced in iron concentration, to consumers who are at risk of malnutrition. In order to achieve biofortification, it is critical to understand the processes of iron uptake, regulation, transport dynamics, and whole-plant iron storage and how to manipulate them in individual crops. In this review, case studies of staple food crops including rice, wheat, and cassava are used to introduce iron biofortification strategies in both monocotyledonous and dicotyledonous species, along with a discussion of consumer-based considerations for the deployment of biofortified crops also presented.

Accumulation of zinc, iron and selenium in wheat as affected by phosphorus supply in salinised condition

Biofortification of zinc (Zn), iron (Fe) and selenium (Se) in crops could be affected by environmental factors such as soil salinity and phosphorus supply levels, as well as by the genotypic effect. Two pot experiments were conducted with one examined the effects of P supply and salinity on plant growth and Zn, Fe and Se uptake in wheat, and the other examined genotypic differences in Zn, Fe and Se accumulation among 20 wheat genotypes. The results of the first pot study showed significant interactive effects between P supply and salinity on Zn, Fe and Se accumulation. Increasing salinity at the same P supply level increased shoot Zn concentrations, but significantly decreased total shoot Zn amount owing to decreased aboveground biomass. An increased accumulation of total shoot Fe and Se in P-added treatments, relative to the no-P treatments, was mainly due to increased aboveground biomass. The results of the second pot study showed substantial genotypic variations in Zn, Fe and Se accumulation; principal component analysis (PCA) suggested that agronomic traits and nutrient accumulation were controlled by independent genetic mechanisms. These results indicated that the amount of P supply is a key factor regulating biomass and accumulation of Zn, Fe and Se in certain saline soils; the sizable genotypic difference in Zn, Fe and Se accumulation observed in salinised conditions has provided potential scope for genetic improvement by breeding strategies.

Importance of the Rhizosphere Microbiota in Iron Biofortification of Plants.

Increasing the iron content of plant products and iron assimilability represents a major issue for human nutrition and health. This is also a major challenge because iron is not readily available for plants in most cultivated soils despite its abundance in the Earth’s crust. Iron biofortification is defined as the enhancement of the iron content in edible parts of plants. This biofortification aims to reach the objectives defined by world organizations for human nutrition and health while being environment friendly. A series of options has been proposed to enhance plant iron uptake and fight against hidden hunger, but they all show limitations. The present review addresses the potential of soil microorganisms to promote plant iron nutrition. Increasing knowledge on the plant microbiota and plant-microbe interactions related to the iron dynamics has highlighted a considerable contribution of microorganisms to plant iron uptake and homeostasis. The present overview of the state of the art sheds light on plant iron uptake and homeostasis, and on the contribution of plant-microorganism (plant-microbe and plant-plant-microbe) interactions to plant nutritition. It highlights the effects of microorganisms on the plant iron status and on the co-occurring mechanisms, and shows how this knowledge may be valued through genetic and agronomic approaches. We propose a change of paradigm based on a more holistic approach gathering plant and microbial traits mediating iron uptake. Then, we present the possible applications in plant breeding, based on plant traits mediating plant-microbe interactions involved in plant iron uptake and physiology.

Agronomic bio-fortification of iron, zinc and selenium enhance growth, quality and uptake of different sorghum accessions

Agronomic bio-fortification is one of the main approaches for mitigation of micronutrient shortage in human populations and endorses sustainable production of food and feed. Studies related to agronomic bio-fortification of crops are mainly focused on single or rarely two micronutrients application, and no attempt has made to study the combined effect of zinc (Zn), iron (Fe) and selenium (Se) on forage sorghum. Therefore, this research was accomplished to evaluate the effect of Zn, Fe and Se bio-fortification on diverse sorghum accessions. The field experiments were conducted in a randomised complete block design with a split-plot arrangement. The treatments comprised of Zn (10 mg/L as ZnSO<sub>4</sub>∙5H<sub>2</sub>O), Fe (7 mg/L as FeSO<sub>4</sub>∙7H<sub>2</sub>O), Se (3 mg/L as SeSO<sub>4</sub>) and CK (control) were applied to five sorghum accessions: G<sub>1</sub> (Y-16), G<sub>2</sub> (YSH-166), G<sub>3</sub> (YSH-134), G<sub>4</sub> (YSS-98) and G<sub>5</sub> (YSH-132). According to our results, the sorghum accession G<sub>5</sub> showed superiority over all other accessions and produced maximum values of all growth and quality traits except grains number per panicle and 1 000-grain weight. All applied micronutrients (Zn, Fe and Se) enhanced the growth, quality and uptake of nutrients in sorghum accessions. However, Se recorded the highest plant height, stem diameter, 1 000-grain weight and Zn produced the maximum protein, oil and starch contents. Conclusively, it can be concluded that G<sub>5</sub> with Se must be used to achieve the optimum values of agronomic traits, while G<sub>5</sub> with Zn found more effective to improve the quality traits of sorghum.