Biofortification in Vegetable Crops

Introduction

The most important concerns affecting almost every nation throughout the world include increasing population, insufficient food and nutrition, hunger, vitamin, and micronutrient malnourishment, and so on. Vitamin A deficiency (VAD) is frequent among children and women in underdeveloped nations, resulting in over 600,000 deaths among children under the age of five every year. Micronutrient malnourishment in the population is dominated by 60 percent iron, 30 percent zinc, 30 percent iodine, and 15 percent selenium. Inadequate availability of these vital vitamins and minerals resulted in a wide range of health and physical issues in people. Traditional agricultural practices can improve the nutritional content of plant foods to some extent, but biofortification is the practice of incorporating nutrient fortification into food crops through agronomic, conventional, and transgenic breeding methods to provide a long-term strategy to combat the negative effects of vitamin and nutrient deficiencies. The majority of horticultural crops, including banana, cassava, beans, potato, orange sweet potato (OSP), cowpea, pumpkin, and others, have been biofortified. Several conventional and transgenic kinds have already been introduced, with more on the way. The results of efficacy and effectiveness tests, as well as recent distribution successes, show that biofortification is a potentially successful strategy for alleviating hidden hunger. Biofortification is the process of adding nutritious value to a crop. It refers to the addition of nutrients to crops to mitigate the negative economic and health repercussions of vitamin and mineral deficits in individuals.

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Bio-fortification is the process of enhancing the bioavailable mineral content of food crops by genetic modification. Producing bio-fortified crops enhances their growth efficiency on soils with depleted or unavailable mineral composition. Plant breeding for increased phytonutrients is most easily accomplished with crops that have short juvenile periods to reach the fruiting stage, such as vegetables, berries, and melons, but it is a much longer-term strategy for tree-fruit and nuts, which generally require a juvenile period of many years before fruit-set is possible. Discovering plant variations with increased phytonutrient content within germplasm collections or existing commercial cultivars is an alternative strategy.

This can identify lines that are already acceptable to consumers, or it can indicate a prospective donor parent with the proper phytonutrient background for transfer into a more edible plant variety.

Importance of Biofortification

Biofortification is a reasonably cost-effective, sustainable, and long-term method of delivering additional micronutrients in distant rural regions, as well as giving naturally-fortified foods to population groups with limited access to commercially marketed fortified foods. Biofortified staple foods cannot provide as many minerals and vitamins per day as supplements or industrially fortified meals, but they can aid by boosting the daily adequacy of micronutrient intakes across individuals across the lifespan.Biofortification is not expected to treat micronutrient deficiencies or eliminate them in all population groups. No single intervention will solve the problem of micronutrient malnutrition, but biofortification complements existing interventions to sustainably provide micronutrients to the most vulnerable people in a comparatively inexpensive and cost-effective way. For instance, according to World Health Organization (WHO) estimation, biofortification could help cure two billion people suffering from iron deficiency-induced anemia.

Table 1: Sources of nutrients from vegetables

Nutrients	Vegetables
Carbohydrate	Sweet potato, potato, cassava
Protein	Pea, lima bean, French bean, cowpea
Vitamin A	Carrot, spinach, pumpkin
Vitamin B1	Tomato, chili, garlic, leek, pea
Vitamin C	Chilli, sweet pepper, cabbage, drumstick
Calcium	Hyacinth bean, amaranthus, palak
Iron	Amaranthus, palak, spinach, lettuce, bitter gourd
Phosphorous	Pea, lima bean, taro, drumstick leaves
Vitamin B5	Palak, amaranthus, bitter gourd, pointed gourd
Iodine	Tomato, sweet pepper, carrot, garlic, okra
Sodium	Celery, green onion, Chinese cabbage, radish

Methods of Biofortification

Biofortification can be achieved through three strategies:

• Agronomic Biofortification

• Conventional plant breeding

• Genetic engineering

Agronomic Biofortification

Application of fertilizers to increase the micronutrients in edible parts. The most suitable micronutrients for agronomic biofortification are Zinc (foliar applications of ZnSO4), Iodine (Soil application of iodide or iodate), and Selenium (as selenate). Foliar application is the quick and easy method of nutrient application to the fortification of micronutrients (Fe, Zn, Cu, etc.) in plants. Several studies have found that the mycorrhizal associations increase Fe, Se, Zn, and Cu concentrations in crop plants. AM-fungi increase the uptake and efficiency of micronutrients like Zn, Cu, Fe, etc. Sulphur oxidizing bacteria increase the sulphur content in onion.

Biofortification of crops with Iron:

Tomato plants can tolerate high levels of iodine, stored both in the vegetative tissues and fruits at concentrations that are more than sufficient for the human diet, and conclude that tomato is an excellent crop for iodine-biofortification programs. The fruit concentration of iodine detected in 5 mM iodide–treated plants was more than enough to cover a daily human intake of 150 μg. Increasing iron levels of Amaranthus plants by using S.platensis as microbial inoculant when compared with control and he also reported that Spirulina platensis has been used as a biofortifying agent to enhance the iron the status in Amaranthus gangeticus plant.

Biofortification of crops with Zinc

The relationship between tuber Zn concentration and foliar Zn application followed a saturation curve, reaching a maximum at approx. 30 mg Zn kg–1 DM at a foliar Zn application rate of 1.08 g plant–1. Despite a 40-fold increase in shoot Zn concentration compared to the unfertilized controls following foliar Zn fertilization with 2.16 g Zn plant–1. The use of fertilizer "River" during the cultivation of sweet pepper, eggplant, and tomatoes helps to be enriched by zinc. Biofortified vegetables contain 6.60-8.59 % of Zn more than control.

Biofortification of crops with Selenium

Se-enriched S. pinnata is valuable as a soil amendment for enriching broccoli and carrots with healthful forms of organic-Se. Onions and carrots were bio-fortified by foliar application of a solution of 77Se(IV) that was enriched to 99.7% as 77Se. In Brassica vegetables, selenium application did not affect the yield or oil content [32]. A high accumulation of Se in the seeds and meal of (1.92–1.96 μg Se g−1) was detected.

Conventional plant breeding

Traditional breeding mainly focused on yield attributes and resistance breeding forthe last four decades and a lack of priority on nutritional aspects leads to decreased amount of nutrient status in the existed varieties. Examples of minerals whose mean concentration in the dry matter have declined in several plant-based foods are Fe, Zn, Cu, and Mg. Recent progress in conventional plant breeding has emphasizedthe fortification of important vitamins, antioxidants, and micronutrients. The potential to increase the micronutrient density of staple foods by conventional breeding requires adequate genetic variation in concentrations of β-carotene, other functional carotenoids, iron, zinc, and other minerals exists among cultivars, making a selection of nutritionally appropriate breeding materials possible.

Genetic Engineering

Genetic engineering (also called genetic modification) is a process that uses laboratory-based technologies to alter the DNA makeup of an organism. This may involve changing a single base pair (A-T or C-G), deleting a region of DNA, or adding a new segment of DNA. For example, genetic engineering may involve adding a gene from one species to an organism from a different species to produce a desired trait. Used in research and industry, genetic engineering has been applied to the production of cancer therapies, brewing yeasts, genetically modified plants and livestock, and more

Table 2: Example of biofortification in vegetable crops

Crop	Biofortified element/mineral/vitamin
Tomato	Chlorogenic acid, stilbene, flavonoids, anthocyanin,Folate, phytoene, lycopene β-carotene, provitamin A ,Zinc, Iodine
Potato	Amino acid,protein, anthocyanin, starch, carbohydrate (fructan)
Onion Brocolli	Selenium
Lettuce,Beans	Iron
Carrot	Calcium
Radish	Selenium
Brassica spp.	Selenium,Carotene
Cassava	Protein, carotene, and mineral contents
Sweet Potato	Protein,Carotein
Brocoli	Selenium
Cucumber	Potassium
Spinach	Iodine
Pumpkin	Carotenoids

Conclusion

Biofortification is a viable method of addressing malnourished populations in somewhat remote rural regions by distributing naturally fortified meals to those who do not have easy access to commercially promoted fortified foods, which are more commonly available in cities. As a result, biofortification and commercial fortification are extremely complimentary. Finally, effective nutrition is dependent on adequate intakes of a variety of nutrients and other chemicals, in combinations and quantities that are yet unknown. Thus, increasing the intake of a variety of non-staple foods is the greatest and final answer to eliminate undernutrition as a public health concern in developing nations. However, this will take decades to accomplish, as well as intelligent government policies and a relatively big investment in agricultural research and other public and on-farm infrastructure.

To sum up in the words of M.S. Swaminathan, “GM foods have the potential to solve many of the world’s hunger and malnutrition problems and to help protect and preserve the environment by increasing yield, quality and reducing reliance upon chemical pesticides. Yet there are many challenges ahead for governments, especially in the areas of safety testing, regulation, industrial policy, and food labeling.”

Future thrust

Crop biofortification is a difficult task. Many plant breeding initiatives aim to increase production, tolerance to biotic and abiotic stresses, and food palatability. In recent years, improving nutritional quality has been included as a new breeding goal. Collaboration between plant breeders and nutrition specialists is critical to achieving these goals. Furthermore, certain biofortification projects cannot be implemented due to a lack of adequate genetic variety for micronutrients in the germplasm. In such cases, genetic engineering methods must be used, and coordination between plant breeders and molecular scientists is vital. The regulatory approval procedure, which is both costly and time-consuming, is the most significant barrier to the commercial use of GM crops.Biofortification is a potential agriculturally based technique for improving the nutritional status of the world's starving populations. As a result, significant resources should be committed to biofortification efforts.

About the Authors

Moomal Bharadwaj1* and Harshwardhan Bhardwaj2 1College of Agriculture, Ummedganj, Agriculture University Kota - 324001 (Rajasthan)

2Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur - 313001 (Rajasthan)

*Corresponding Author: moomalbharadwaj@gmail.com