Simultaneously inhibit cadmium and arsenic uptake in rice (Oryza sativa L.) by Selenium enhanced iron plaque: Performance and mechanism.

Selenium (Se) fortification is witnessed to simultaneously inhibit absorbing Cadmium (Cd) and Arsenic (As) by rice plants, but the mechanism is unclear. Here, the effects of Se on the root morphology, iron plaque (IP) content, soil Fe2+ content, radial oxygen loss (ROL), and enzyme activities of the rice plants in the soil contaminated by Cd and As were intensively investigated through the hydroponic and soil experiments. Se effectively alleviated the toxic effects of Cd and As on the plants and the dry weight, root length, and root width were increased by 203.18%, 33.41%, and 52.81%, respectively. It also elucidated that ROL was one of the key factors to elevate IP formation by Se and the specific pathways of Se enhancing ROL were identified. ROL of the plants in the experiment group treated by Se was increased 36.76%, and correspondingly IP was magnified 50.37%, compared to the groups with Cd and As. It was owing to Se significantly increased the root porosity (62.11%), facilitating O2 transport to the roots. Additionally, Se enhanced the activities of catalase (CAT) and superoxide dismutase (SOD) to promote the catalytic degradation of ROS induced by Cd and As stress. It indirectly increased O2 release in the rhizosphere, which benefit to form more robust IP serve as stronger barrier to Cd and As. The results of our study provide a novel molecular level insight for Se promoting root IP to block Cd and As uptake by the rice plants.

CAX control: multiple roles of vacuolar cation/H+ exchangers in metal tolerance, mineral nutrition and environmental signalling.

Plant vacuolar transporters, particularly CAX (Cation/H+ Exchangers) responsible for Ca2+/H+ exchange on the vacuole tonoplast, play a central role in governing cellular pH, ion balance, nutrient storage, metal accumulation, and stress responses. Furthermore, CAX variants have been employed to enhance the calcium content of crops, contributing to biofortification efforts. Recent research has uncovered the broader significance of these transporters in plant signal transduction and element partitioning. The use of genetically encoded Ca2+ sensors has begun to highlight the crucial role of CAX isoforms in generating cytosolic Ca2+ signals, underscoring their function as pivotal hubs in diverse environmental and developmental signalling networks. Interestingly, it has been observed that the loss of CAX function can be advantageous in specific stress conditions, both for biotic and abiotic stressors. Determining the optimal timing and approach for modulating the expression of CAX is a critical concern. In the future, strategically manipulating the temporal loss of CAX function in agriculturally important crops holds promise to bolster plant immunity, enhance cold tolerance, and fortify resilience against one of agriculture's most significant challenges, namely flooding.

Overexpression of Wheat Selenium-Binding Protein Gene TaSBP-A Enhances Plant Growth and Grain Selenium Accumulation under Spraying Sodium Selenite.

Selenium (Se) is an essential trace element for humans. Low concentrations of Se can promote plant growth and development. Enhancing grain yield and crop Se content is significant, as major food crops generally have low Se content. Studies have shown that Se biofortification can significantly increase Se content in plant tissues. In this study, the genetic transformation of wheat was conducted to evaluate the agronomic traits of non-transgenic control and transgenic wheat before and after Se application. Se content, speciation, and transfer coefficients in wheat grains were detected. Molecular docking simulations and transcriptome data were utilized to explore the effects of selenium-binding protein-A TaSBP-A on wheat growth and grain Se accumulation and transport. The results showed that TaSBP-A gene overexpression significantly increased plant height (by 18.50%), number of spikelets (by 11.74%), and number of grains in a spike (by 35.66%) in wheat. Under normal growth conditions, Se content in transgenic wheat grains did not change significantly, but after applying sodium selenite, Se content in transgenic wheat grains significantly increased. Analysis of Se speciation revealed that organic forms of selenomethionine (SeMet) and selenocysteine (SeCys) predominated in both W48 and transgenic wheat grains. Moreover, TaSBP-A significantly increased the transfer coefficients of Se from solution to roots and from flag leaves to grains. Additionally, it was found that with the increase in TaSBP-A gene overexpression levels in transgenic wheat, the transfer coefficient of Se from flag leaves to grains also increased.

Biofortification of Triticum species: a stepping stone to combat malnutrition.

BACKGROUND: Biofortification represents a promising and sustainable strategy for mitigating global nutrient deficiencies. However, its successful implementation poses significant challenges. Among staple crops, wheat emerges as a prime candidate to address these nutritional gaps. Wheat biofortification offers a robust approach to enhance wheat cultivars by elevating the micronutrient levels in grains, addressing one of the most crucial global concerns in the present era. MAIN TEXT: Biofortification is a promising, but complex avenue, with numerous limitations and challenges to face. Notably, micronutrients such as iron (Fe), zinc (Zn), selenium (Se), and copper (Cu) can significantly impact human health. Improving Fe, Zn, Se, and Cu contents in wheat could be therefore relevant to combat malnutrition. In this review, particular emphasis has been placed on understanding the extent of genetic variability of micronutrients in diverse Triticum species, along with their associated mechanisms of uptake, translocation, accumulation and different classical to advanced approaches for wheat biofortification. CONCLUSIONS: By delving into micronutrient variability in Triticum species and their associated mechanisms, this review underscores the potential for targeted wheat biofortification. By integrating various approaches, from conventional breeding to modern biotechnological interventions, the path is paved towards enhancing the nutritional value of this vital crop, promising a brighter and healthier future for global food security and human well-being.

Genetic Biofortification of Winter Wheat with Selenium (Se).

Wheat is one of the three most important cereals in the world, along with rice and maize. It serves as the primary food and source of energy for about 30-40% of the world's population. However, the low levels of micronutrients in wheat grains can lead to deficiencies of those micronutrients in people whose dietary habits are mostly based on cereals such as wheat. Apart from iron (Fe) and zinc (Zn), a lack of selenium (Se) is also one of the biggest problems in the world. The essentiality of Se has been confirmed for all animals and humans, and the lack of this micronutrient can cause serious health issues. Wheat dominates the world's cereal production, so it is one of the best plants for biofortification. Due to the fact that agronomic biofortification is not an economical or environmentally acceptable approach, genetic improvement of cereals such as wheat for the enhanced content of micronutrients in the grain represents the most efficient biofortification approach.

Ionomic Profile of Rice Seedlings after Foliar Application of Selenium Nanoparticles.

Nanotechnology has been increasingly used in plant sciences, with engineered nanoparticles showing promising results as fertilizers or pesticides. The present study compared the effects in the foliar application of Se nanoparticles (SeNPs) or sodium selenite-Se(IV) on rice seedlings. The degree of plant growth, photosynthetic pigment content, and concentrations of Se, Na, Mg, K, Ca, Mn, Co, Cu, Zn, As, Cd, and Pb were evaluated. The results showed that the application of SeNPs at high concentrations (5 mg L-1), as well as the application of Se(IV), inhibited plant growth and increased the root concentrations of As and Pb. The application of SeNPs at 0.5 mg L-1 significantly increased Se accumulation in the aerial part from 0.161 ± 0.028 mg kg-1 to 0.836 ± 0.097 mg kg-1 without influencing physiological, chemical, or biochemical parameters. When applied to leaves, SeNPs tended to remain in the aerial part, while the application of Se(IV) caused a higher Se translocation from the shoots to the roots. This study provides useful information concerning the uptake, accumulation, and translocation of different Se formulations in rice seedlings and their effect on plant ionomic profiles, thus showing that the foliar application of SeNPs at low concentrations can be an effective and safe alternative for rice biofortification.

Tracing isotopically labeled selenium nanoparticles in plants via single-particle ICP-mass spectrometry.

Agronomic biofortification using selenium nanoparticles (SeNPs) shows potential for addressing selenium deficiency but further research on SeNPs-plants interaction is required before it can be effectively used to improve nutritional quality. In this work, single-particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) was used for tracing isotopically labeled SeNPs (82SeNPs) in Oryza sativa L. tissues. For this purpose, SeNPs with natural isotopic abundance and 82SeNPs were synthesized by a chemical method. The NPs characterization by transmission electron microscopy (TEM) confirmed that enriched NPs maintained the basic properties of unlabeled NPs, showing spherical shape, monodispersity, and sizes in the nano-range (82.8 ± 6.6 nm and 73.2 ± 4.4 nm for SeNPs and 82SeNPs, respectively). The use of 82SeNPs resulted in an 11-fold enhancement in the detection power for ICP-MS analysis, accompanied by an improvement in the signal-to-background ratio and a reduction of the size limits of detection from 89.9 to 39.9 nm in SP-ICP-MS analysis. This enabled 82SeNPs to be tracked in O. sativa L. plants cultivated under foliar application of 82SeNPs. Tracing studies combining SP-ICP-MS and TEM-energy-dispersive X-ray spectroscopy data confirmed the uptake of intact 82SeNPs by rice leaves, with most NPs remaining in the leaves and very few particles translocated to shoots and roots. Translocation of Se from leaves to roots and shoots was found to be lower when applied as NPs compared to selenite application. From the size distributions, as obtained by SP-ICP-MS, it can be concluded that a fraction of the 82SeNPs remained within the same size range as that of the applied NP suspension, while other fraction underwent an agglomeration process in the leaves, as confirmed by TEM images. This illustrates the potential of SP-ICP-MS analysis of isotopically enriched 82SeNPs for tracing NPs in the presence of background elements within complex plant matrices, providing important information about the uptake, accumulation, and biotransformation of SeNPs in rice plants.

An Ex-Ante Analysis of the Impact of Biofortified Zinc Rice on Dietary Zinc Inadequacy: Evidence from Bangladesh, Indonesia, and the Philippines.

BACKGROUND: South, East, and Southeast Asia are among the regions of the world with the highest estimated prevalence of inadequate zinc intake. Because populations in those regions eat rice as their main staple, zinc biofortification of rice can potentially improve zinc intake, especially among the most vulnerable. OBJECTIVES: We modeled the impact of the consumption of zinc-biofortified rice on zinc intake and inadequacy among women of childbearing age and young children nationally in Indonesia, the Philippines, and at a subnational level in Bangladesh. METHODS: We conducted an ex-ante analysis by applying increments of zinc content in rice, from a baseline level of 16 parts per million (ppm) to 100 ppm, and based on rice consumption data to substitute levels of conventional rice with zinc-biofortified rice varying between 10% and 70%. RESULTS: Among all datasets evaluated from these 3 countries, the prevalence of dietary zinc inadequacy at baseline was 94%-99% among women of childbearing age, 77%-100% among children 4-5 y old, and 27%-78% among children 1-3 y old. At the current breeding target of 28 ppm, zinc-biofortified rice has the potential to decrease zinc inadequacy by ≤50% among women and children in rural Bangladesh and among children in the Philippines where consumption of rice is higher compared with Indonesia. CONCLUSIONS: Our analysis shows that increasing zinc content in rice ≤45 ppm reduces the burden of zinc inadequacy substantially, after which we encourage programs to increase coverage to reach the highest number of beneficiaries.

Strategies and Challenges of Microbiota Regulation in Baijiu Brewing.

The traditional Chinese Baijiu brewing process utilizes natural inoculation and open fermentation. The microbial composition and abundance in the microecology of Baijiu brewing often exhibit unstable characteristics, which directly results in fluctuations in Baijiu quality. The microbiota plays a crucial role in determining the quality of Baijiu. Analyzing the driving effect of technology and raw materials on microorganisms. Elucidating the source of core microorganisms and interactions between microorganisms, and finally utilizing single or multiple microorganisms to regulate and intensify the Baijiu fermentation process is an important way to achieve high efficiency and stability in the production of Baijiu. This paper provides a systematic review of the composition and sources of microbiota at different brewing stages. It also analyzes the relationship between raw materials, brewing processes, and brewing microbiota, as well as the steps involved in the implementation of brewing microbiota regulation strategies. In addition, this paper considers the feasibility of using Baijiu flavor as a guide for Baijiu brewing regulation by synthesizing the microbiota, and the challenges involved. This paper is a guide for flavor regulation and quality assurance of Baijiu and also suggests new research directions for regulatory strategies for other fermented foods.

Inoculation of Zaopei with biofortification: Inducing variation in community structure and improving flavor compounds in Nongxiangxing baijiu.

The deterioration of the quality of raw liquor caused by the low content of ethyl hexanoate in Nongxiangxing baijiu has become a pervasive problem in the baijiu industry. Therefore, this study attempted to increase the synthesis of ethyl hexanoate by microorganisms with high esterase activity to increase Zaopei fermentation. The results showed that biofortification was a feasible and important way to improve the quality of the raw liquor and increase the ethyl hexanoate content. Adding Bacillus subtilis, Staphylococcus epidermidis, and Millerozyma farinosa for biofortified fermentation disturbed the microbial community structure of Zaopei and increased the abundance of Wickerhamomyces, Saccharomyces, and Thermoascus. The contents of ethyl hexanoate, ethyl valerate, ethyl caprylate, and ethyl heptanoate also increased noticeably in baijiu. The results of E-nose and sensory analysis tested and verified that the baijiu in the fortified group had better flavor characteristics.

Zn solubilizing bacteria (ZSB) mitigate toxicity of silver and Titanium dioxide nanoparticles in Mung bean by increasing photosynthetic pigment content.

Zn-deficiency, a global health challenge affects one-third of the world population. Zn-biofertilizer offer an efficient and cost-effective remedy. As Zn-biofertilizer can improve plant growth and grain's Zn-content ensuring improved dietary Zn-supply. This study sought to understand how silver and TiO2 nanoparticles in the rhizosphere affect the activity of Zn-solubilization bacteria (ZSB) and plant growth. Two ZSB strains Bacillus sp. D-7 and Pseudomonas sp. D-117 with excellent Zn-solubilization efficiency of 254 and 260%, respectively were isolated and characterized using polyphasic characterization including 16S rRNA gene sequencing to formulate an effective Zn-biofertilizer. The plant growth promoting activity of this biofertilizer in Mung bean was checked in the presence and absence of various doses of TiO2 and Ag-NPs and was compared with plant grown without biofertilizer. The change in rate of seed germination, vegetative growth (shoot and root length, fresh and dry weight), photosynthetic pigment and Zn-content was checked. Lower doses of nanomaterials (50 and 100 mg kg⁻¹ soil) slightly promoted the plant growth compared to control. While, higher doses (200 and 400 mg kg⁻¹ soil) inhibited the growth. A maximum decrease of shoot length, root length, fresh-weight, and dry-weight of 57.1, 53.9, 53.1, and 10.4% respectively was observed with 400 mg kg⁻¹ of Ag-NPs. However, in the presence of ZSB, the decrease at the same Ag-NP concentration was 41.6, 31.5, 27.4, and 6.6, respectively. These results strongly suggest that Zn-solubilizing bacteria improve resilience to nanoparticles toxicity and helps in Zn fortification in Mung bean even under nanomaterial stress.

Selenium mitigates the loss of nutritional quality in rice grown at an elevated concentration of carbon dioxide.

Atmospheric CO2 enrichment has the potential to improve rice (Oryza sativa L.) yield, but it may also reduce grain nutritional quality, by reducing mineral and protein concentrations. Selenium (Se) fertilization may improve rice grain nutritional composition, but it is not known if this response extends to plants grown in elevated carbon dioxide concentration (eCO2). We conducted experiments to identify the impacts of Se fertilization on yield and quality of rice grains in response to eCO2. The effect of the Se treatment was not significant for the grain yield within each CO2 condition. However, the reduction in macronutrients and micronutrients under eCO2 was mitigated in grains of plants fertilized with Se. Fertilization with Se increased the concentration of Se in roots, flag leaves, and grains independently of atmospheric CO2 concentrations. Elevation of the transcripts of ion transport-related genes could, at least partially, explain the positive relationship between mineral concentrations and grain mass resulting from Se fertilization under eCO2. Treatment with Se also increased the accumulation of total protein in grains under eCO2. Overall, our results revealed that Se fertilization represents a potential asset to maintain rice grain nutritional quality in a future with rising atmospheric CO2 concentration.

Effects of different selenium biofortification methods on Pleurotus eryngii polysaccharides: Structural characteristics, antioxidant activity and binding capacity in vitro.

The effects of selenium biofortification methods involving sodium selenite and selenium yeast on the structural characteristics, antioxidant activity and binding capacity of Pleurotus eryngii polysaccharides were investigated. Sodium selenite Se-enriched Pleurotus eryngii polysaccharides (Se-SPEP), selenium yeast Se-enriched Pleurotus eryngii polysaccharides (Se-YPEP), and Pleurotus eryngii polysaccharides (PEP) had Se contents of 20.548 ± 1.561, 19.822 ± 0.613, and 0.052 ± 0.016 µg/g, respectively. Compared with PEP, Se-SPEP and Se-YPEP had lower molecular weight and contained the same monosaccharides in varying molar ratios. The results of FT-IR, PS, ZP, and SEM indicated significant alterations in structural characteristics following selenium biofortification. Se-PEPs exhibited superior activity against ABTS, DPPH, and ·OH radicals, as well as the higher binding capacity for Cd2+ and Cu2+ compared to natural polysaccharides. The binding capacity of the polysaccharides for Cd2+ and Cu2+ was higher at pH 6.8 compared to pH 2.0, while the opposite was observed for Pb2+. Furthermore, Se-PEPs exhibited a significantly higher binding capacity for Cd2+ and Cu2+ at both pH levels compared to natural polysaccharides (P < 0.05). Se-YPEP displayed higher antioxidant activity than Se-SPEP, with their binding capacities reversed. These data indicated that selenium biofortification methods have different positive impacts on the structure and activity of polysaccharides compared to natural polysaccharides, making Se-PEPs promising dietary supplements for safeguarding the body against the risks posed by food-derived heavy metals.

Pleurotus extract-mediated selenium and zinc nanoparticles exhibited improved yield of biofortified fruit bodies.

The current study was aimed for the generation of Pleurotus extracellular extract-mediated selenium and zinc-oxide nanoparticles (NPs). The Pleurotus djamor (PD) and Pleurotus sajor-caju (PSC) extracts were incubated with different concentrations of sodium selenate and zinc acetate to yield BioSeNPs and BioZnONPs. The NPs formation led to visual color change (brick-red and white for Se and Zn nanosols, respectively). The synthesized NPs were spherical with size of 124 and 68 nm and 84 and 91 nm for PD and PSC BioSeNPs and BioZnONPs respectively. The UV absorbance peaks were recorded at 293.2 and 292.2 nm and 365.9 and 325.5 nm for BioSeNPs and BioZnONPs derived from PD and PSC respectively. FT-IR spectroscopy indicated specific functional group adoration on metal-based NPs. On supplementation in straw, these NPs improved the fruit body yield besides enhancing their protein and Se/ Zn contents. These biofortified mushrooms could be potential dietary supplement/ nutraceutical.

Biofortification as a solution for addressing nutrient deficiencies and malnutrition.

Malnutrition, defined as both undernutrition and overnutrition, is a major global health concern affecting millions of people. One possible way to address nutrient deficiency and combat malnutrition is through biofortification. A comprehensive review of the literature was conducted to explore the current state of biofortification research, including techniques, applications, effectiveness and challenges. Biofortification is a promising strategy for enhancing the nutritional condition of at-risk populations. Biofortified varieties of basic crops, including rice, wheat, maize and beans, with elevated amounts of vital micronutrients, such as iron, zinc, vitamin A and vitamin C, have been successfully developed using conventional and advanced technologies. Additionally, the ability to specifically modify crop genomes to improve their nutritional profiles has been made possible by recent developments in genetic engineering, such as CRISPR-Cas9 technology. The health conditions of people have been shown to improve and nutrient deficiencies were reduced when biofortified crops were grown. Particularly in environments with limited resources, biofortification showed considerable promise as a long-term and economical solution to nutrient shortages and malnutrition. To fully exploit the potential of biofortified crops to enhance public health and global nutrition, issues such as consumer acceptance, regulatory permitting and production and distribution scaling up need to be resolved. Collaboration among governments, researchers, non-governmental organizations and the private sector is essential to overcome these challenges and promote the widespread adoption of biofortification as a key part of global food security and nutrition strategies.

Enriched-Fe maize kernels to prevent dietary Fe deficiency in humans.

Iron (Fe) biofortification of edible organs without influencing crop yield is challenging, and potential solutions are largely unknown. Recently, Yan et al. identified a key regulator NAC78 (NAM/ATAF/CUC DOMAIN TRANSCRIPTION FACTOR 78) that enriches Fe in maize kernels without compromising crop yield. This may provide new crop yield management strategies for Fe acquisition and nutritional security.

Growth of Romaine Lettuce in Eggshell Powder Mixed Alginate Hydrogel in an Aeroponic System for Water Conservation and Vitamin C Biofortification.

Vitamin C is crucial for physical well-being, and its deficiency can lead to severe health consequences. Biofortification has been used to address this deficiency by enhancing vitamin C in plants. Additionally, soilless agriculture has been used to conserve and optimize water use in comparison to conventional agriculture. While hydrogels have been shown to improve water conservation and are used for biofortification in crops, their application has only been explored in soil-based and hydroponic farming. The aeroponics system is a plant-growing method that has shown potential for increasing yields and biomass while conserving water and nutrients. In this paper, we have developed an aeroponic-compatible medium to grow romaine lettuce (Lactuca sativa L.) with eggshell powder (ESP) mixed with calcium-alginate hydrogel as a substrate and nutrient source aiming to conserve water and incorporate vitamin C through biofortification. Herein, lower water spray time and higher intervals, with varied gel types and ESP concentrations, resulted in healthy lettuce growth. Plants treated with 0.5% ascorbic acid-absorbed ESP-mixed alginate hydrogel for biofortification showed higher levels of vitamin C compared to the traditional method. This study suggests using an alginate hydrogel-ESP-based substrate in aeroponics to reduce water usage and enhance plant biofortification of vitamin C.

Selenobacteria-mediated Se transformation and uptake involving the unique genetic code.

Selenium (Se) is a crucial micronutrient for human health. Plants are the primary source of Se for humans. Selenium in the soil serves as the primary source of Se for plants. The soil contains high total Se content in large areas in Guangxi, China. However, the available Se is low, hindering Se uptake by plants. Microorganisms play a pivotal role in the activation of Se in the soil, thereby enhancing its uptake by plants. In this study, selenobacteria were isolated from Se-rich soils in Guangxi. Then two selenobacteria strains, YLB1-6 and YLB2-1, representing the highest (30,000 µg/mL) and lowest (10,000 µg/mL) Se tolerance levels among the Se-tolerant bacteria, were selected for subsequent analysis. Although the two selenobacteria exhibited distinct effects, they can significantly transform Se species, resulting in a decrease in the soil residual Se (RES-Se) content while concurrently increasing the available Se (AVA-Se) content. Selenobacteria also enhance the transformation of Se valencies, with a significant increase observed in soluble Se6+ (SOL-Se6+). Additionally, selenobacteria can elevate the pH of acidic soil. Selenobacteria also promote the uptake of Se into plants. After treatment with YLB1-6 and YLB2-1, the Se content in the aboveground part of Chinese flowering cabbage increased by 1.96 times and 1.77 times, respectively, while the Se accumulation in the aboveground part of the plant significantly increased by 104.36% and 81.69%, respectively, compared to the control. Further whole-genome sequencing revealed the genetic difference between the two selenobacteria. Additionally, 46 and 38 candidate genes related to selenium utilization were identified from YLB1-6 and YLB2-1, respectively. This work accelerates our understanding of the potential molecular mechanism of Se biofortification by selenobacteria. It also provides microorganisms and gene targets for improving crop varieties or microorganisms to exploit the rich Se source in soil.

Combined application of zinc oxide and iron nanoparticles enhanced Red Sails lettuce growth and antioxidants enzymes activities while reducing the chromium uptake by plants grown in a Cr-contaminated soil.

Soil contamination with chromium (Cr) is becoming a primary ecological and health concern, specifically in the Kasur and Sialkot regions of Pakistan. The main objective of the current study was to evaluate the impact of foliar application of zinc oxide nanoparticles (ZnO NPs) (0, 25, 50, 100 mg L-1) and Fe NPs (0, 5, 10, 20 mg L-1) in red sails lettuce plants grown in Cr-contaminated soil. Our results showed that both ZnO and Fe NPs improved plant growth, and photosynthetic attributes by minimizing oxidative stress in lettuce plants through the stimulation of antioxidant enzyme activities. At ZnO NPs (100 mgL-1), dry weights of shoots and roots and fresh weights of shoots and roots were improved by 53%, 58%, 34%, and 45%, respectively, as compared to the respective control plants. The Fe NPs treatment (20 mgL-1) increased the dry weight of shoots and the roots and fresh weights of shoots and roots by 53%, 76%, 42%, and 70%, respectively. Application of both NPs reduced the oxidative stress caused by Cr, as evident by the findings of the current study, i.e., at the ZnO NPs (100 mgL-1) and Fe NPs (20 mgL-1), the EL declined by 32% and 44%, respectively, in comparison with respective control plants. Moreover, Fe and ZnO NPs enhanced the Fe and Zn contents in red sails lettuce plants. Application of ZnO NPs at 100 mg L-1 and Fe NPs at 20 mg L-1, improved the Zn and Fe contents in plant leaves by 86%, and 68%, respectively, as compared to the control plants. This showed that the exogenous application of these NPs helped in Zn and Fe fortification in plants. At similar of concenteration ZnO NPs, CAT and APX activities were improved by 52% and 53%, respectively. Similarly, the POD contents were improved by 17% and 45% at 5 and 10 mg/L of Fe NPs. Furthermore, ZnO and Fe NPs limited the Cr uptake by plants, and the concentration of Cr in the leaves of lettuce was under the threshold limit. The exogenous application of ZnO NPs (100 mg L-1) and Fe NPs (20 mg L-1) reduced the Cr uptake in the leaves of red sails lettuce by 57% and 51%, respectively. In conclusion, ZnO and Fe NPs could be used for the improvement of plant growth and biomass as well as nutrient fortification in stressed environments. These findings not only underscore the efficacy of nanoparticle-assisted phytoremediation but also highlight its broader implications for sustainable agriculture and environmental health. However, future studies on other crops with molecular-level investigations are recommended for the validation of the results.

ZnO and Fe NPs improved the growth and photosynthesis of red sails lettuce plantsBoth NPs enhanced antioxidants enzymes activities in stressed plantsNPs mediated response reduced the oxidative stress and Cr uptake in red sails lettuceZnO and Fe NPs resulted in Zn and Fe fortification, respectively, in red sails lettuce.

Impact of foliar application of iron and zinc fertilizers on grain iron, zinc, and protein contents in bread wheat (Triticum aestivum L.).

Introduction: Micronutrient deficiencies, particularly iron (Fe) and zinc (Zn), are prevalent in a large part of the human population across the world, especially in children below 5 years of age and pregnant women in developing countries. Since wheat constitutes a significant proportion of the human diet, improving grain Fe and Zn content in wheat has become important in improving human health. Objective: This study aimed to quantify the effect of foliar application of iron sulfate heptahydrate (FeSO4.7H2O) and zinc sulfate heptahydrate (ZnSO4.7H2O) and their combination on grain Fe and Zn concentrations, as well as grain protein content (GPC). The study also aimed to assess the utility of these applications in large field conditions. Methods: To address this issue, field experiments were conducted using 10 wheat cultivars and applying a foliar spray of FeSO4.7H2O (0.25%) and ZnSO4.7H2O (0.50%) separately (@400 L of solution in water per hectare during each spray) and in combination at two different crop growth stages (flowering and milking) for three consecutive crop seasons (2017-2020). The study used a split-plot design with two replications to assess the impact of foliar application on GFeC, GZnC, and GPC. In addition, an experiment was also conducted to assess the effect of soil (basal) @ 25 kg/ha ZnSO4, foliar @ 2 kg/ha, ZnSO4.7H2O (0.50%), and the combination of basal + foliar application of ZnSO4 on the grain micronutrient content of wheat cultivar WB 02 under large field conditions. Results: GFeC increased by 5.1, 6.1, and 5.9% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. GZnC increased by 5.2, 39.6, and 43.8% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. DBW 173 recorded the highest increase in GZnC at 56.9% with the combined foliar application of FeSO4 and ZnSO4, followed closely by HPBW 01 at 53.0% with the ZnSO4 foliar application, compared to the control. The GPC increased by 6.8, 4.9, and 3.3% with foliar applications of FeSO4, ZnSO4, and their combination, respectively. Large-plot experiments also exhibited a significant positive effect of ZnSO4 not only on grain Zn (40.3%, p ≤ 0.001) and protein content (p ≤ 0.05) but also on grain yield (p ≤ 0.05) and hectoliter weight (p ≤ 0.01), indicating the suitability of the technology in large field conditions. Conclusion: Cultivars exhibited a slight increase in GFeC with solitary foliar applications of FeSO4, ZnSO4, and their combination. In contrast, a significant increase in GZnC was observed with the foliar application of ZnSO4 and the combined application of FeSO4 and ZnSO4. In terms of GPC, the most significant enhancement occurred with the foliar application of FeSO4, followed by ZnSO4 and their combination. Data demonstrated the significant effect of foliar application of ZnSO4 on enhancing GZnC by 39.6%. Large plot experiments also exhibited an increase of 40.3% in GZnC through the foliar application of ZnSO4, indicating the effectiveness of the technology to be adopted in the farmer's field.