Agronomic Biofortification of Zinc in Pakistan: Status, Benefits, and Constraints

Abstract

Micronutrient malnutrition (e.g., zinc) is one of the major causes of human disease burden in the developing world. Zinc (Zn) deficiency is highly prevalent in the Pakistani population (22.1%), particularly in women and children (under 5 years) due to low dietary Zn intake. In Pakistan, wheat is the primary staple food and is poor in bioavailable Zn. However, the number of malnourished populations has decreased over the last decade due to multiplied public awareness, accelerated use of Zn fertilizers (particularly in wheat and rice), initiation of several national/international research initiatives focusing on Zn biofortification in staple crops and availability of supplements and Zn fortified meals merchandise, nonetheless a large number of people are facing Zn or other micronutrient deficiencies in the country. There are few reports highlighting the significant increase in daily dietary Zn uptake in population consuming biofortified wheat (Zincol-2016) flour; indicating the positive prospect of biofortification interventions up scaling in lowering the risk of dietary Zn deficiency in rural and marginalized communities. Zinc fertilizer strategy has not only helped in enhancing the grain Zn concentration, but it also helped in improving crop yield with high economic return. In addition, Zn biofortified seeds have exhibited strong inherent ability to withstand abiotic stresses and produce higher grain yield under diverse climatic conditions. However, there are many constraints (soil, environment, genetic diversity, antinutrients concentration, socioeconomic factors etc.) that hinder the success of biofortification interventions. This review highlights the status of Zn deficiency in Pakistan, the success of agronomic and genetic biofortification interventions. It also discusses the economics of agronomic biofortification and cost effectiveness of Zn fertilization in field conditions in Pakistan and the potential of Zn biofortified seeds against abiotic stresses. Furthermore, it also highlights the constraints which limit the sustainability of biofortification interventions.

Cross Talk Between Zinc-Solubilizing Bacteria and Plants: A Short Tale of Bacterial-Assisted Zinc Biofortification

“…Zinc is a "wonderful micronutrient, " necessary for all organisms, acted as a prosthetic group for approximately 3,000 proteins in animals and humans, and inimitable in numerous metabolic activities of plants such as (a) the activation of a series of miscellaneous enzymes ("RNA polymerases, " "carbonic anhydrase, " and "superoxide dismutase") and (b) the formation and metabolism of biomolecules (proteins, carbohydrates, and lipids) (7,(17)(18)(19)(20)20). In plants, the deficiency of Zn decreases their growth, their ability to survive under stressful conditions, and finally the production of chlorophyll, which affect the plant health and its productivity (21,22).…”

High-Temperature and Drought Stress Effects on Growth, Yield and Nutritional Quality with Transpiration Response to Vapor Pressure Deficit in Lentil

“…However, micronutrient deficiencies are currently becoming more serious due to the high consumption of carbohydrate-rich cereal-based diets, which are low in micronutrients and vitamins [ 5 , 6 ]. Micronutrient malnutrition, commonly known as hidden hunger, affects more than 2 billion people in developing countries, while all over the world, >3 billion people suffer from micronutrient deficiencies [ 7 , 8 , 9 , 10 , 11 ]. In the last decade, efforts have been made to reduce the risks of malnutrition using several approaches including nutrient supplementation, diet diversification and food fortification.…”

The Role of Sulfur in Agronomic Biofortification with Essential Micronutrients

“…This treatment improved grain Fe concentration in wheat by about 28% in China, and 21% in Iran, whereas in Canada, it remained ineffective. By increasing soil N application, shoot and grain Fe contents significantly enhanced both under field and greenhouse conditions [ 204 , 205 , 206 , 207 , 208 , 209 , 210 , 211 , 212 , 213 , 214 ]. Application of Fe fertilizers alone either in inorganic (FeSO 4 ) or in chelated form (e.g., Fe-EDDHA, Fe- EDTA or Fe-citrate) presented a small positive impact on increasing Fe content in grain, while in combination with soil N application, it enhanced by 47%.…”

“…At a given Fe treatment, soil N supply can enhance shoot Fe concentrations by up to 70%. Foliar application of urea also improved grain Fe concentration [ 204 , 205 , 206 , 207 , 208 , 209 , 210 , 211 , 212 , 213 , 214 ].…”