Food security is a global concern as micronutrient malnutrition, and health disorders are negatively impacting the socioeconomic conditions all over the world. Biofortification is directly related to reducing micronutrient malnutrition and food insecurities. However, there should be direct and target-oriented strategies to improve mineral loading in edible plant parts. Therefore, this article is intended to discuss the importance of the biofortification of cereals, wheat, rice, and chickpea.
Biofortification of chickpea to Achieve Food Security
Chickpea is an important nutritious pulse crop and it is quite often used by human beings. It is a good source of micronutrients. By increasing the concentration of micronutrients in chickpea the absorption of mineral nutrients by the human digestive system can be enhanced. Selection of proper site and genetic material can be a sustainable strategy for providing food-based solutions to global micronutrient malnutrition by biofortification. https://soilplantfood.com/reducing-hidden-hunger-by-fertilization-of-edible-plants/
Improving Micronutrients in Pulses for Biofortification
Usually, pulses contain a variety of micronutrients but the mineral biofortification of chickpea offers multiple health benefits. It is one of the ancient pulse crops and its first domestication was in the middle east about 7450 years ago. About 9.4 million metric tons of chickpea are produced across the globe.
Pulse crops like lentils, field peas, and chickpea are gaining popularity due to healthy food choices. By increasing the concentration of mineral elements in pulses the problem of micronutrient malnutrition can be significantly reduced. Chickpea can serve as a whole food solution to micronutrient malnutrition. https://soilplantfood.com/elimination-of-hidden-hunger-by-micronutrients-remobilization/
Other than biofortification, biodiversity enhances human food security because it plays a direct role to improve ecosystem functioning and sustainability. Food security and climate change are strongly interconnected because food quality and quantity are significantly affected by global warming and the greenhouse phenomenon. The condition of food security in the U.S and other countries is declining due to climate change and poor policies. Therefore, it is essentially important to teach people what is food security and why is it important.
Wheat Biofortification to Attain Food Security
Wheat makes more than 50% of the diet and it is a major staple food crop. Worldwide wheat is consumed on daily basis and it provides 25% of proteins and 20% calories. Also, it is an important source of micronutrients (Shewry and Hey, 2015). Especially in developing countries, it is the most important source of calorie intake but wheat is inherently low in Zn.
Zn Levels for Wheat Biofortification
For wheat fortification, the level of Zn is increased from 25 to 37 microgram zinc per gram in the grain part. This biofortified wheat crop can be produced by hybridization, genetic manipulation, etc. The Highest Zn concertation is found in bran, whereas micronutrient contents in seeds are also reduced by the milling and polishing processes.
The mortality rate is being increased due to consumption of poor quality wheat having fewer nutrient concentrations. Especially food security has been identified as a problem in the areas containing low soil Zn levels and deprived communities.
CPG-B1 Allele for Wheat Biofortification
Wild type CPG- B1 allele has been incorporated into modern wheat cultivars for the improvement of nutritional contents. This quantitative trait CPG is greatly influenced by environmental conditions and genotypes. It causes a significant increase in Fe and Zn contents in grains in a wide variety of environments and genetic backgrounds.
It causes no negative impacts on yield and yield components. Biofortification through biotechnology of wheat protocols is a promising approach to improve mineral nutrients in wheat. There has been good ongoing work about NIFA vitamin A biofortification of wheat grains using a tilling mutant based approach.
Characterizing bread wheat genotypes of Pakistani origin for grain zinc biofortification potential is greatly helpful to improve Zn loading in wheat grains. Moreover, identification of the mechanism of biofortification of iron in wheat is also important to resolve the issues of nutrients loading for agricultural sustainability and food security. However, sound understanding is required for agricultural sustainability and intensive production practices. Decreasing the use of pesticides and herbicides can help agricultural sustainability and food security.
Foliar Zn Fertilization for Wheat for Food Security
Application of foliar Zn fertilization causes a significant increase in Zn concentration of wheat grains especially at the time of grain filling period (Cakmak et al., 2010). Increased micronutrient contents in wheat will also increase the wheat yield. Development of wheat varieties that delivers more mineral nutrients in wheat grains, agricultural productivity will be improved because both plants and human beings need micronutrients. https://soilplantfood.com/physiology-of-micronutrients-accumulation-and-factors-affecting-biofortification/
Micronutrients Diversity in Wheat and Molecular Markers to Achieve Food Security
There is a wide diversity of micronutrients in wheat. Molecular markers can assist the breeding techniques for the development of wheat genotypes containing a significantly greater amount of critical micronutrients. Among cereals, wheat is the most promising crop to increase the Zn and Fe contents in grains.
Using Wild Wheat Relatives to Improves Cultivars
Several improvements in modern wheat cultivars are possible. Wild relatives of wheat have higher concentrations of grain nutrients and broader genetic diversity. So these characters can be incorporated into modern wheat cultivars for better nourishment.
Biofortification of Rice for Food Security
50% of the world population is using rice as a staple food crop. Rice provides 21% per capita energy and 15% of protein to the human population all across the world. Rice is extensively cultivated in Asia. Appropriate zinc and Fe fertilization greatly improve the yield and quality of grains by enhanced uptake and accumulation in grains.
Zn Deficiency in Rice
Rice is the most susceptible crop to zinc deficiency. Zinc deficiency is even observed after the application of zinc fertilizers to the soil but this deficiency is related to total bioavailable zinc contents. Zn accumulation is also related to soil pH. In saline soils, the zinc uptake is reduced in rice crops. It was reported that consumption of Fe biofortified rice impressively amended the Fe eminence of nonanemic Filipino women.
Effects of Severe Zn deficiency on Rice Plants
Under rice cultivation, Zn deficiency is very common. Severe deficiency reduces the number of tillers and also delays crop maturity. Adequate uptake of Zn and Fe during the growth and developmental stages of rice enriches the rice grains with these mineral nutrients and also increases the yield on a sustainable basis. Increased absorption by roots does not always associate with higher accretion of micronutrients in grains as well. This phenomenon has been observed in the case of Fe in rice.
Reduction in Grain Zn Contents by Milling, Polishing, and Pearling
Milling, polishing, and pearling processes also cause the loss of micronutrients in rice grains (Borg et al., 2009). Polished rice has an only little fraction of micronutrients or completely devoid of micronutrients (Lucca et al., 2006). In rice, the essential micronutrients are more exclusively stored in husk, embryo, and aleurone so they are easily removed by the milling process.
Approaches to Reduce Zn and Fe deficiencies in Rice to Achieve Food Security
Several approaches have been followed to increase Zn and Fe contents in rice grains to mitigate micronutrient malnutrition in human beings. To improve the shelf life of rice grains pericarp, testae, embryo, and aleurone layers are removed during the milling processes so the only endosperm is left as an edible part. Focus on rice breeding just started recently.
Progress regarding the micronutrient contents in rice was also limited but now much work has been started by some organizations on both national and international levels. Improvement in the nutritional quality of rice would exert significant impacts on human health. https://soilplantfood.com/role-of-iron-for-life-and-iron-deficiency-across-the-globe/
Biofortification of Cereals
In terms of calories, cereals are the most important source for human beings. Wheat, rice, and maize are the main staple food crops to feed the resource-poor population in the world. Cereals are grasses that belong to the monocots family which are cultivated for edible grains.
Mostly their grains are used as basic food stock in many parts of the world. But the low concentration of Fe and Zn in these foods is causing serious health issues around the globe. So Zn and Fe enriched cereal grains would cause significant health impacts.
Uptake and Movement of Zn in Cereals
In cereals, the xylem is discontinuous at the base end of each seed. So Zn should be transferred from the xylem to the phloem before entering the grain. It causes a significant bottleneck for Zn accumulation in the grains. The bottleneck of Zn biofortification varies between the cereals.
Continuous Zn uptake during grain filling stages and continuity in loading of endosperm from xylem is a key process. In cereals, grain loading is more important than root shoot loading. The contribution of Zn translocation from leaves is much more important for Zn allocation to cereals grains than Zn uptake during grain filling stages.
Moreover, the adequate concentration of these mineral elements also increases crop production. As compare to Zn, Fe is less mobile in phloem parts of cereals.
Effective Requirements to Target Cereals Biofortification
To effectively target biofortification in cereals, few key steps must be targeted.
- Increased mineral uptake from the soil.
- Increased transport and accumulation of micronutrients in grains.
- Enhanced sequestration of mineral elements to endosperm than husk and aleuronic part.
- Reducing the anti-nutritional factors in grains.
- Identification of promoter substances for improving micronutrient bioavailability.
- Increasing the promoters of mineral bioavailability for grains.
- Most reliable bioavailability models should be explored as basic mechanisms for underlying micronutrient deficiency.