Harnessing Finger Millet to Combat Calcium Deficiency in Humans: Challenges and Prospects

First principles modelling of the ion binding capacity of finger millet

Finger millet, a cereal grain widely consumed in India and Africa, has gained more attention in recent years due to its high dietary fibre (arabinoxylan) and trace mineral content, and its climate resilience. The aim of this study was to understand the interactions between potassium (K+), calcium (Ca2+) and zinc (Zn2+) ions and the arabinoxylan structure and determine its ion-binding capacity. Three variations of a proposed model of the arabinoxylan structure were constructed and first principles Density Functional Theory calculations were carried out to determine the cation-binding capacity of the arabinoxylan complexes. Zn2+-arabinoxylan complexes were highly unstable and thermodynamically unfavourable in all three models. Ca2+ and K+ ions, however, form thermodynamically stable complexes, particularly involving two glucuronic acid residues as a binding pocket. Glucuronic acid residues are found to play a key role in stabilising the cation-arabinoxylan complex, and steric effects are more important to the stability than charge density. Our results highlight the most important structural features of the millet fibre regarding ion-storage capacity, and provide valuable preliminary data for confirmatory experimental studies and for the planning of clinical trials where the bioavailability of bound ions following digestion may be tested.

Finger millet (Eleusine coracana) enhancement through genomic resources and breeding methods: current implications and potential future interventions

Finger millet (Eleusine coracana) is an essential staple crop in many regions of Africa and Asia, valued for its nutritional content and resilience in challenging agro-ecological conditions. The enhancement of finger millet through genomic resources and breeding methods represents a promising avenue for addressing food and nutritional security. Current efforts in this field have harnessed genomic technologies to decipher the crop's genetic diversity and identify key traits related to yield, disease resistance, and nutritional content. These insights have facilitated the development of improved varieties through selective breeding, accelerating the crop's adaptation to changing environmental conditions. In the future, continued advancements in genomics and breeding methodologies hold the potential to further enhance finger millet's resilience, nutritional value, and productivity, ultimately benefiting both farmers and consumers. This review article synthesizes the current state of research and development in finger millet enhancement through the integration of genomic resources and innovative breeding methods. The utilization of these insights in selective breeding has already yielded promising results in developing improved finger millet varieties that meet the evolving needs of farmers and consumers. Moreover, this article discusses potential future interventions, including the continued advancement of genomics, precision breeding, and sustainable agricultural practices. These interventions hold the promise of further enhancing finger millet's adaptability to changing climates, its nutritional quality, and its overall productivity, thereby contributing to food security and improved livelihoods in finger millet-dependent regions.

A comparison of the bioaccessible calcium supplies of various plant-based products relative to bovine milk

Calcium deficiency is widespread globally, especially in diets with minimal consumption of dairy. It is therefore important to identify plant-based sources of calcium that can make a meaningful contribution to calcium intakes for populations following diets with a minimum supply of dairy products. The best sources of calcium have a high calcium content and bioavailability. Therefore, we evaluated the gross and bioaccessible calcium supplies of 25 plant-based products from 5 food groups considered to be good and important sources of calcium. Bioaccessible calcium was examined using the INFOGEST static digestion model in which isotopically labelled 43Ca was used as a tracer of reagent calcium to improve accuracy of bioaccessibility measurements. The gross calcium content varied widely amongst all the food products, ranging between 7.48 and 959 mg/100 g fresh weight (fw), with approximately 50 % of the products being equivalent to or surpassing the calcium content of skimmed milk. Bioaccessibility of calcium was equally variable, ranging from about 0.1 - 50 %. The lowest bioaccessibility (<10 %) was found in spinach, plant-based beverages, tofu, dried figs and tahini and was attributed to: 1. the high content of oxalate and phytate in some of the products, and 2. the low solubility of tricalcium phosphate which was used for fortification in the plant-based beverages. The remaining products generally had a high bioaccessibility that was similar to, or higher than that of skimmed milk (∼30 %). When both bioaccessibility and recommended serving portions were considered, only 3 products were identified as good sources of calcium, requiring 0.2 - 1.4 servings to equal the bioaccessible supply from skimmed milk. The top three sources of plant-based calcium identified were kale, finger millet and fortified white bread in that order, with kale providing 5 times more bioaccessible calcium than 1 serving of skimmed milk. Moderate sources of calcium where 1.5 - 3 servings was equivalent to 1 serving of skimmed milk included wholemeal bread, some bean varieties (black chickpeas, chickpeas, kidney beans, peas), broccoli, cabbage and almond drink. The rest of the products were either of low calcium content, poor bioaccessibility, and/or not consumed in sufficient quantities to make a significant contribution to daily requirements. White bread was a good source of calcium as it was fortified with calcium carbonate and this suggests that mandatory widescale fortification of staple cereals with this form of calcium should be considered a viable approach to augment dietary calcium intakes in vulnerable populations. Low bioaccessibility of fortified calcium in plant-based beverages, often marketed as good sources of calcium, suggests the need for regulation and for further in vivo studies to validate bioavailability of calcium in these products.

Exploration of nutritional, pharmacological, and the processing trends for valorization of finger millet (Eleusine coracana): A review

High nutrient variability and food security are the needs of the hour. Millets may be as effective as other cereal crops for dealing with severe malnutrition and increasing global population problems. Due to their physiologically active components, millets have attracted more research interest. Finger millet (FM), one of the climate-resilient and minor cereal crop species, is well known for several health benefits, primarily attributed to its nutritional value and polyphenolic content. FM seed coat phenolics exhibit excellent anti-diabetic, anti-oxidant, antimicrobial, anti-osteoporosis, wound healing, anti-lithiatic, inhibiting collagen glycation, cross-linking, and enzyme properties, which may serve well for the pharmacological purposes. Furthermore, the processing of FM is an important factor in its commercial use. It is necessary to invent some novel technologies to increase the productivity of FM by lowering the cost of processing and its effective utilization in the pharmaceutical and food industries. The literature presented will further explore the potential prospects of processing as well as value-added utilization and its nutritional and pharmacological aspects in view of initiating further research in the food industry to formulate ready-to-eat and ready-to-cook products, thereby acting as future crops for sustainability.

Effects of Individual or Combined Deficiency of Phosphorous and Zinc on Phenotypic, Nutrient Uptake, and Molecular Responses of Finger Millet (Eleusine coracana): A Nutri-Rich Cereal Crop

Deficiencies of either phosphorus (P) or zinc (Zn) or both are one of the major abiotic constraints influencing agricultural production. Research on the effects of individual or combined P and Zn deficiency is limited in cereals. This study reports the effects of the individual or combined deficiency of inorganic phosphate (Pi) and Zn on the phenotypic, root hair modification, nutrient uptake, and molecular responses of finger millet (Eleusine coracana), a nutri-rich cereal crop. Finger millet seedlings were grown hydroponically under control (+Pi+Zn), individual Pi deficiency (-Pi), individual Zn deficiency (-Zn), and combined Pi and Zn deficiency (-Pi-Zn) conditions for 30 days to find the phenotypic, root hair modification, nutrient uptake, and molecular responses. Compared to the individual -Zn condition, the individual -Pi condition had more of an effect in terms of biomass reduction. The combined -Pi-Zn condition increased the root hair length and density compared to the other three conditions. The individual -Zn condition increased the Pi uptake, while the individual -Pi condition favored the Zn uptake. EcZIP2 was highly upregulated in shoot tissues under the individual -Zn condition, and EcPHT1;2 was highly expressed in root tissues under the individual -Pi condition. This is the first study to report the effects of the individual or combined deficiency of Pi and Zn in finger millet and may lead to future studies to better manage P and Zn deficiency.

Managing Diabetes Mellitus With Millets: A New Solution

Diabetes mellitus (DM) is the leading cause of morbidity and mortality, and the disease's prevalence is increasing with each passing day. DM can be prevented and controlled with modifications to the diet, especially by incorporating millet in the diet. Throughout history, eating habits have been recognized for their significant contribution to promoting health and wellness by eating foods rich in nutrients. Millet is an underutilized food crop with many benefits for health, with the most beneficial being low glycemic index, high fiber content, polyunsaturated fatty acids (PUFA), non-acid-forming potential, and gluten-free. In addition to staple food crops, such as wheat, rice, and foxtail millet, millets are still highly nutritious and beneficial and have great potential to help the world combat the food insecurity many countries face today. Millets are in the top positions of recommended dietary charts with their numerous health benefits and antioxidant properties.

Genome analyses reveal population structure and a purple stigma color gene candidate in finger millet

Finger millet is a key food security crop widely grown in eastern Africa, India and Nepal. Long considered a 'poor man's crop', finger millet has regained attention over the past decade for its climate resilience and the nutritional qualities of its grain. To bring finger millet breeding into the 21^st century, here we present the assembly and annotation of a chromosome-scale reference genome. We show that this ~1.3 million years old allotetraploid has a high level of homoeologous gene retention and lacks subgenome dominance. Population structure is mainly driven by the differential presence of large wild segments in the pericentromeric regions of several chromosomes. Trait mapping, followed by variant analysis of gene candidates, reveals that loss of purple coloration of anthers and stigma is associated with loss-of-function mutations in the finger millet orthologs of the maize R1/B1 and Arabidopsis GL3/EGL3 anthocyanin regulatory genes. Proanthocyanidin production in seed is not affected by these gene knockouts.

Varietal and processing influence on nutritional and phytochemical properties of finger millet: A review

Food and nutrition insecurity is a problem for the majority of developing nations; incidentally, some underutilized crops have the potential to increase food security. A minor cereal grain called finger millet (Eleusine coracana L.) is widely cultivated in various regions of India and Africa and is consumed for its numerous health advantages. There is a wealth of research on the nutritional and health benefits of this crop, but little is known about how varietal difference and processing affect these qualities. Therefore, this study reviewed the effects of variety and different processing methods on the nutrition, antinutrients, phytochemicals, and antioxidative properties of finger millet and its probable uses in ensuring nutrition and food security. Finger millet is a nutritious cereal with relatively high values of protein, vitamins, minerals, fibre, and energy. The amount of minerals, particularly calcium and potassium, is larger than what is found in the most popular grains, including wheat and rice. The grain of finger millet is non-glutinous and contains only 1.3% fat; in contrast to other types of millet which are noticeably higher in dietary fibre, protein, ash, and fat. The coloured varieties particularly have high levels of minerals, antioxidants, and phytochemicals. The nutritional and phytochemical qualities of finger millet are affected by the cultivars, varieties, and geographical locations. This study elucidates the qualities of finger millet varieties and methods of processing which will help in the selection of appropriate cultivars for food applications.

Genome-wide transcriptome analysis of the orphan crop tef (Eragrostis tef (Zucc.) Trotter) under long-term low calcium stress

Calcium (Ca²⁺) is one of the essential mineral nutrients for plant growth and development. However, the effects of long-term Ca²⁺ deficiency in orphan crops such as Tef [(Eragrostis tef) (Zucc.) Trotter], which accumulate high levels of Ca in the grains, remained unknown. Tef is a staple crop for nearly 70 million people in East Africa, particularly in Ethiopia and Eritrea. It is one of the most nutrient-dense grains, and is also more resistant to marginal soils and climatic conditions than main cereals like corn, wheat, and rice. In this study, tef plants were grown in a hydroponic solution containing optimum (1 mM) or low (0.01 mM) Ca²⁺, and plant growth parameters and whole-genome transcriptome were analyzed. Ca⁺²-deficient plants exhibited leaf necrosis, leaf curling, and growth stunting symptoms. Ca²⁺ deficiency significantly decreased root and shoot Ca, potassium (K), and copper content in both root and shoots. At the same time, it greatly increased root iron (Fe) content, suggesting the role of Ca²⁺ in the uptake and/or translocation of these minerals. Transcriptomic analysis using RNA-seq revealed that members of Ca²⁺ channels, including the cyclic nucleotide-gated channels and glutamate receptor-like channels, Ca²⁺-transporters, Ca²⁺-binding proteins and Ca²⁺-dependent protein kinases were differentially regulated by Ca⁺² treatment. Moreover, several Fe/metal transporters, including members of vacuolar Fe transporters, yellow stripe-like, natural resistance-associated macrophage protein, and oligo-peptide transporters, were differentially regulated between shoot and root in response to Ca²⁺ treatment. Taken together, our findings suggest that Ca²⁺ deficiency affects plant growth and mineral accumulation by regulating the transcriptomes of several transporters and signaling genes.

Achieving nutritional security in India through iron and zinc biofortification in pearl millet (Pennisetum glaucum (L.) R. Br.)

The health problems caused by iron (Fe) and zinc (Zn) deficiency plague developing and underdeveloped countries. A vegetarian person mainly depends on cereal based diet with low quantity of Fe and Zn. Biofortification is an economical and sustainable approach to challenge the micronutrient malnutrition problem globally. Pearl millet (Pennisetum glaucum (L.) R. Br.) is one of the nutri-cereals and mostly grown under hot, dry conditions on infertile soils of low water-holding capacity, where other crops generally fail. It contains anti-nutrient compounds like phytic acid and polyphenols which reduce the mineral bioavailability because of their chelating properties. Biofortification of pearl millet is like a double-edged sword which cuts down the economic burden and simultaneously supplies required nutrition to the poor, offering a great scope for food security as well as nutritional security. With this background, this review focus on biofortification of grain Fe and Zn content in pearl millet. Genetic research on Fe and Zn uptake and accumulation in pearl millet grain is crucial in identifying the 'bottlenecks' in biofortification. The review also reveals the need and strategies for increasing bioavailability of Fe and Zn in humans by increasing promoters and decreasing anti-nutritional factors in pearl millet.

A high-density linkage map of finger millet provides QTL for blast resistance and other agronomic traits

Finger millet [Eleusine coracana (L.) Gaertn.] is a critical subsistence crop in eastern Africa and southern Asia but has few genomic resources and modern breeding programs. To aid in the understanding of finger millet genomic organization and genes underlying disease resistance and agronomically important traits, we generated a F_2:3 population from a cross between E. coracana (L.) Gaertn. subsp. coracana accession ACC 100007 and E. coracana (L.) Gaertn. subsp. africana , accession GBK 030647. Phenotypic data on morphology, yield, and blast (Magnaporthe oryzae) resistance traits were taken on a subset of the F_2:3 population in a Kenyan field trial. The F_2:3 population was genotyped via genotyping-by-sequencing (GBS) and the UGbS-Flex pipeline was used for sequence alignment, nucleotide polymorphism calling, and genetic map construction. An 18-linkage-group genetic map consisting of 5,422 markers was generated that enabled comparative genomic analyses with rice (Oryza sativa L.), foxtail millet [Setaria italica (L.) P. Beauv.], and sorghum [Sorghum bicolor (L.) Moench]. Notably, we identified conserved acrocentric homoeologous chromosomes (4A and 4B in finger millet) across all species. Significant quantitative trait loci (QTL) were discovered for flowering date, plant height, panicle number, and blast incidence and severity. Sixteen putative candidate genes that may underlie trait variation were identified. Seven LEUCINE-RICH REPEAT-CONTAINING PROTEIN genes, with homology to nucleotide-binding site leucine-rich repeat (NBS-LRR) disease resistance proteins, were found on three chromosomes under blast resistance QTL. This high-marker-density genetic map provides an important tool for plant breeding programs and identifies genomic regions and genes of critical interest for agronomic traits and blast resistance.

Interventions to improve calcium intake through foods in populations with low intake

Calcium intake remains inadequate in many low- and middle-income countries, especially in Africa and South Asia, where average intakes can be below 400 mg/day. Given the vital role of calcium in bone health, metabolism, and cell signaling, countries with low calcium intake may want to consider food-based approaches to improve calcium consumption and bioavailability within their population. This is especially true for those with low calcium intake who would benefit the most, including pregnant women (by reducing the risk of preeclampsia) and children (by reducing calcium-deficiency rickets). Specifically, some animal-source foods that are naturally high in bioavailable calcium and plant foods that can contribute to calcium intake could be promoted either through policies or educational materials. Some food processing techniques can improve the calcium content in food or increase calcium bioavailability. Staple-food fortification with calcium can also be a cost-effective method to increase intake with minimal behavior change required. Lastly, biofortification is currently being investigated to improve calcium content, either through genetic screening and breeding of high-calcium varieties or through the application of calcium-rich fertilizers. These mechanisms can be used alone or in combination based on the local context to improve calcium intake within a population.

Comparative Study of AMMI- and BLUP-Based Simultaneous Selection for Grain Yield and Stability of Finger Millet [Eleusine coracana (L.) Gaertn.] Genotypes

Finger millet, an orphan crop, possesses immense potential in mitigating climate change and could offer threefold security in terms of food, fodder, and nutrition. It is mostly cultivated as a subsistence crop in the marginal areas of plains and hills. Considering the changes in climate inclusive of recurrent weather vagaries witnessed every year, it is crucial to select stable, high-yielding, area-specific, finger millet cultivars. Sixty finger millet varieties released across the country were evaluated over six consecutive rainy seasons from 2011 to 2016 at the Agricultural Research Station, Vizianagaram. The genotype × environment interaction (GEI) was found to be significant in the combined ANOVA. Furthermore, the Additive Main effects and Multiplicative Interaction (AMMI) analysis asserted that genotypes and the GEI effects accounted for approximately 89% of the total variation. Strong positive associations were observed in an estimated set of eleven stability parameters which were chosen to identify stable genotypes. Furthermore, Non-parametric and Parametric Simultaneous Selection indices (NP-SSI and P-SSI) were calculated utilizing AMMI-based stability parameter (ASTAB), modified AMMI stability value (MASV), and Modified AMMI Stability Index (MASI) to identify stable high yielders. Both methods had inherent difficulties in ranking genotypes for SSI. To overcome this, the initial culling [i.e., SSI with culling strategy (C-SSI)] of genotypes was introduced for stability. In the C-SSI method, the top ten genotypes were above-average yielders, while those with below-average yield were observed in NP-SSI and P-SSI methods. Similarly, the estimation of best linear unbiased prediction (BLUP)-based simultaneous selections, such as harmonic mean of genotypic values (HMGV), relative performance of genotypic values (RPGV), and harmonic mean of relative performance of genotypic values (HMRPGV), revealed that none of the top ten entries had below-average yield. The study has proven that C-SSI and BLUP-based methods were equally worthy in the selection of high-yielding genotypes with stable performance. However, the C-SSI approach could be the best method to ensure that genotypes with a considerable amount of stability are selected. The multi-year trial SSI revealed that entries Indaf-9, Sri Chaitanya, PR-202, and A-404; and VL324 and VL146 were ascertained to be the most stable high-yielding genotypes among medium-to-late and early maturity groups, respectively.

Genome-editing in millets: current knowledge and future perspectives

Millets are small seeded cereal crops predominantly cultivated and consumed by resource-poor farmers in the semi-arid tropics of Asia and Africa. Millets possess rich nutrients and a climate resilience property when compared to the other cereals such as rice and wheat. Millet improvement using modern genetic and genomic tools is falling behind other cereal crops due to their cultivation being restricted to less developed countries. Genome editing tools have been successfully applied to major cereal crops and, as a result, many key traits have been introduced into rice, wheat and maize. However, genome editing tools have not yet been used for most millets although they possess rich nutrients. The foxtail millet is the only millet utilised up to now for genome editing works. Limited genomic resources and lack of efficient transformation systems may slow down genome editing in millets. As millets possess many important traits of agricultural importance, high resolution studies with genome editing tools will help to understand the specific mechanism and transfer such traits to major cereals in the future. This review covers the current status of genome editing studies in millets and discusses the future prospects of genome editing in millets to understand key traits of nutrient fortification and develop climate resilient crops in the future.

Nutritional Significance and Antioxidant-Mediated Antiaging Effects of Finger Millet: Molecular Insights and Prospects

Aging is a multifaceted process that is associated with progressive, lethal, and unalterable changes like damage to different molecules (DNA, proteins, and lipids), cells, tissues, and organs. It is an inevitable process but can be delayed by both genetic and dietary interventions. Besides aging, premature death and age-associated diseases can be dealt with diet regulation and the use of compounds that inhibit the stress responsiveness or promote the damage repair signaling pathways. Natural compounds offer a repertoire of highly diverse structural scaffolds that can offer hopeful candidate chemical entities with antiaging potential. One such source of natural compounds is millets, which are minor cereals with an abundance of high fiber, methionine, calcium, iron, polyphenols, and secondary metabolites, responsible for numerous potential health benefits. The present review article elucidates the nature and significance of different phytochemicals derived from millets with a major focus on finger millet and highlights all the important studies supporting their health benefits with special emphasis on the antiaging effect of these compounds. The present article also proposes the possible mechanisms through which millets can play a significant role in the suppression of aging processes and aging-related diseases by influencing genetic repair, protein glycation, and stress-responsive pathways. We further discuss well-established natural compounds for their use as antiaging drugs and recommend raising awareness for designing novel formulations/combinations from them so that their maximum antiaging potential can be harnessed for the benefit of mankind.

Improvement of small seed for big nutritional feed

Exploding global population, rapid urbanization, salinization of soils, decreasing arable land availability, groundwater resources, and dynamic climatic conditions pose impending damage to our food security by reducing the grain quality and quantity. This issue is further compounded in arid and semi-arid regions due to the shortage of irrigation water and erratic rainfalls. Millets are gluten (a family of proteins)-free and cultivated all over the globe for human consumption, fuel, feed, and fodder. They provide nutritional security for the under- and malnourished. With the deployment of strategies like foliar spray, traditional/marker-assisted breeding, identification of candidate genes for the translocation of important minerals, and genome-editing technologies, it is now tenable to biofortify important millets. Since the bioavailability of iron and zinc has been proven in human trials, the challenge is to make such grains accessible. This review encompasses nutritional benefits, progress made, challenges being encountered, and prospects of enriching millet crops with essential minerals.

Improvement of nutrient bioavailability in millets: Emphasis on the application of enzymes

Millets are a traditional staple food of the dryland regions of the world and are rich in essential nutrients like protein, fatty acids, minerals, vitamins, and dietary fiber. Also, millets commonly synthesize a range of secondary metabolites to protect themselves against adverse conditions. These factors are collectively termed anti-nutritional factors and the existence of these factors in millets might reduce the accessibility of the nutrients in humans. Some of these factors include protease inhibitors, tannins, non-starch polysaccharides-glucans, phytates, and oxalates each of which might directly or indirectly affect the digestibility of nutrients. Methods like soaking, germination, autoclaving, debranning, and the addition of exogenous enzymes have been used to reduce the anti-nutritional factors and elevate the bioavailability of the nutrients. This review summarizes various methods that have been used to improve nutrient bioavailability, specifically emphasizing the use of enzymes to improve nutrient bioavailability from millets. © 2021 Society of Chemical Industry.

Finger Millet [Eleusine coracana (L.) Gaertn]: An Orphan Crop With a Potential to Alleviate the Calcium Deficiency in the Semi-arid Tropics of Asia and Africa

Finger millet plays a vital role in the food and nutritional security of many people in developing countries particularly in Asia and Africa. It is a staple food for poor people in many regions of Asian (India, China, Nepal, and Sri Lanka etc.) and African (South Africa, Ethiopia, Kenya, Uganda, and Nigeria etc.) countries. Finger millet contains nutrient rich components such as dietary fibers, minerals, vitamins, and phytochemicals that include phenolic compounds with several potential health benefits. Calcium (Ca) is an important macronutrient for healthy life of plants, humans and animals. It plays an indispensable role in structure and signaling and its deficiency causes low bone density, osteoporosis, colon cancer etc. Finger millet grains contain exceptionally higher amount of Ca (&gt;300 mg/100 g) when compared to other major cereals. Ca transporter and sensor family genes are involved in the uptake, transport and accumulation of Ca. Understanding the molecular mechanisms of Ca transporter and sensor family genes is important for growth, development and seed fortification in finger millet. Expression analysis of Ca transporter and sensor family genes has been carried out in various tissues of finger millet. Only a very little research work has been done to understand the Ca accumulation in the grains of finger millet. In this review, we discuss the nutritional importance and health benefits of finger millet. We discuss the studies on Ca sensor, accumulation and transport genes that help to improve the grains of finger millet with special reference to Ca. Improved Ca content in finger millet may help to alleviate the Ca deficiency throughout the world particularly in the semi-arid tropics of Asia and Africa.

Calcium Biofortification of Crops-Challenges and Projected Benefits

Despite Calcium (Ca) being an essential nutrient for humans, deficiency of Ca is becoming an ensuing public health problem worldwide. Breeding staple crops with higher Ca concentrations is a sustainable long-term strategy for alleviating Ca deficiency, and particular criteria for a successful breeding initiative need to be in place. This paper discusses current challenges and projected benefits of Ca-biofortified crops. The most important features of Ca nutrition in plants are presented along with explicit recommendations for additional exploration of this important issue. In order for Ca-biofortified crops to be successfully developed, tested, and effectively implemented in most vulnerable populations, further research is required.

Modern India and Dietary Calcium Deficiency-Half a Century Nutrition Data-Retrospect-Introspect and the Road Ahead

Calcium and vitamin D are inseparable nutrients required for bone health. In the past half a century, the dietary calcium intake of rural, tribal, and urban India has declined. Though India is the largest producer of milk and cereals, the major source of calcium in India is through non-dairy products. The highest intake of cereals and lowest intake of milk & milk products was observed in rural and tribal subjects whereas, the intake of cereals, milk & milk products were similar in both urban and metropolitan subjects. One of the reasons for lower calcium intake was the proportion of calcium derived from dairy sources. Over the past half a century, the average 30-day consumption of cereals in the rural and urban population has declined by 30%. The Per Capita Cereal Consumption (PCCC)has declined despite sustained raise in Monthly Per capita Consumption Expenditure (MPCE) in both rural and urban households. The cereal consumption was the highest in the lowest income group, despite spending smaller portion of their income, as cereals were supplied through public distribution system (PDS). About 85% of the Indian population are vitamin D deficient despite abundant sunlight. Dietary calcium deficiency can cause secondary vitamin D deficiency. Though India as a nation is the largest producer of milk, there is profound shortage of calcium intake in the diet with all negative consequences on bone health. There is a decline in dietary calcium in the background of upward revision of RDI/RDA. There is a gap in the production-consumption-supply chain with respect to dietary calcium. To achieve a strong bone health across India, it is imperative to have population based strategies addressing different segments including supplementing dietary/supplemental calcium in ICDS, mid-day-meals scheme, public distribution system, educational strategies. Other measures like mass food fortification, biofortification, bioaddition, leveraging digital technologies, investments from corporate sector are some measures which can address this problem. India is a vast country with diverse social, cultural and dietary habits. No single measure can address this problem and requires a multi-pronged strategic approach to tackle the dietary calcium deficiency to achieve strong bone health while solving the problem of nutritional deficiency.

Foliar application of chitosan nanoparticle improves yield, mineral content and boost innate immunity in finger millet plants

The aim of the present study is to evaluate the potential of chitosan and chitosan nanoparticles (ChNPs) in enhancing the growth and yield of finger millet under greenhouse condition. Foliar application of ChNPs significantly enhanced the growth, yield and mineral content (Fe, Zn, Mn, P, Ca, Mg) when compared to the chitosan and untreated control. ChNPs also induced several defense related enzymes (chitinase, β-1,3 glucanase, chitosanase, protease inhibitors, peroxidase, polyphenol oxidase) in leaves of finger millet plants their by enhancing the innate immune response. This quantitative difference in defense enzymes was also detected qualitatively on polyacrylamide gels. Our results suggest that ChNPs application can be used as an ecofriendly approach to enhance yield and mineral content in finger millet for sustainable production.

Phosphate supply influenced the growth, yield and expression of PHT1 family phosphate transporters in seven millets

Phosphate starvation altered the root morphology and phosphate uptake with the induction of PHT1 family transporter genes in root and shoot tissues of seven millets. Millets are nutrient-rich cereals majorly cultivated in Asia and Africa. Foxtail millet (FoxM), pearl millet (PeaM), finger millet (FinM), kodo millet (KodM), little millet (LitM), proso millet (ProM), and barnyard millet (BarM) were examined for the influence of external phosphorous (P) supply on phenotypic traits, P uptake, yield, and PHosphate Transporter1 (PHT1) family gene expression. Millet seedlings grown under low Pi condition (LPC) produced significantly lower mean values for all traits except for lateral root length (LRL) and lateral root number (LRN) which were increased under LPC. Under LPC, seed weight (SW) also reduced by > 75% and had significantly lower levels of total P (TP) and Pi contents in leaf and root tissues. Expression dynamics of 12 PHT1 family (PHT1;1-1;12) transporters genes were analyzed in 7 millets. PHT1;2 has been found to be a constitutive transporter gene in all millets. Under LPC, root tissues showed the overexpression of PHT1;2, 1;3, 1;4 and 1;9 in FoxM, PHT1;1, 1;2, 1;3, 1;4, 1;8 and 1;10 in PeaM, PHT1;2 and 1;3 in FinM and ProM and PHT1;3, 1;6 and 1;11 in BarM. In leaf, LPC induced the expression of PHT1;3, 1;4 and 1;6 in FoxM, PHT1;2, 1;3, 1;4 and 1;8 in PeaM, PHT1;2, 1;3 and 1;4 in FinM and KodM, PHT1;2 in LitM and PHT1;4 in ProM and BarnM. This comprehensive study on the influence of P in phenotype, physiology, and molecular responses may help to improve the P uptake and its use efficiency of millets in future.

Genome-wide Identification and in silico Analysis of PHT1 Family Genes and Proteins in Setaria viridis: The Best Model to Study Nutrient Transport in Millets

Millets are small-seeded cereals predominantly cultivated and consumed by millions of poor people living in developing countries in Asia and Africa. Limited availability of genomic resources hinders studies of nutrient transport in millets. Two species, foxtail millet [ (L.) P. Beauv.] and its wild relative green foxtail [ (L.) P. Beauv.], are considered to be suitable models to study the genomics of other millets. Understanding the nutrient mobilization of millets is essential for improving nutrient use efficiency and biofortification in millets and other cereal crops. Millets are adapted for low-input agriculture, so understanding and improving the phosphate use efficiency of these plants is important because (i) subsistence farmers cannot afford to buy expensive phosphate fertilizers and (ii) the phosphate rock used for phosphate fertilizer production is depleting quickly. In this minireview, I discuss various studies on nutrient transport in millets and highlight phosphate transport studies. I report the identification and phylogenetic and multiple sequence analyses of 12 PHosphate Transporter1 (PHT1) family genes and proteins of green foxtail for the first time. With the exception of PHT1;5, all other green foxtail PHT1 transporters are closely clustered with foxtail millet PHT1 transporters. The multiple sequence analysis of SvPHT1s revealed that the key residues involved in phosphate and H-binding and transport are well conserved, as in other PHT1 transporters. Efforts need to be undertaken to understand and improve phosphate uptake and utilization in millets to strengthen food security in the developing world.

Finger Millet [Eleusine coracana (L.) Gaertn.] Improvement: Current Status and Future Interventions of Whole Genome Sequence

The whole genome sequence (WGS) of the much awaited, nutrient rich and climate resilient crop, finger millet (Eleusine coracana (L.) Gaertn.) has been released recently. While possessing superior mineral nutrients and excellent shelf life as compared to other major cereals, multiploidy nature of the genome and relatively small plantation acreage in less developed countries hampered the genome sequencing of finger millet, disposing it as one of the lastly sequenced genomes in cereals. The genomic information available for this crop is very little when compared to other major cereals like rice, maize and barley. As a result, only a limited number of genetic and genomic studies has been undertaken for the improvement of this crop. Finger millet is known especially for its superior calcium content, but the high-throughput studies are yet to be performed to understand the mechanisms behind calcium transport and grain filling. The WGS of finger millet is expected to help to understand this and other important molecular mechanisms in finger millet, which may be harnessed for the nutrient fortification of other cereals. In this review, we discuss various efforts made so far on the improvement of finger millet including genetic improvement, transcriptome analysis, mapping of quantitative trait loci (QTLs) for traits, etc. We also discuss the pitfalls of modern genetic studies and provide insights for accelerating the finger millet improvement with the interventions of WGS in near future. Advanced genetic and genomic studies aided by WGS may help to improve the finger millet, which will be helpful to strengthen the nutritional security in addition to food security in the developing countries of Asia and Africa.