Breeding for micronutrients in staple food crops from a human nutrition perspective

Abstract

Over three billion people are currently micronutrient (i.e. micronutrient elements and vitamins) malnourished, resulting in egregious societal costs including learning disabilities among children, increased morbidity and mortality rates, lower worker productivity, and high healthcare costs, all factors diminishing human potential, felicity, and national economic development. Nutritional deficiencies (e.g. iron, zinc, vitamin A) account for almost two-thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Importantly, these crops can be enriched (i.e. 'biofortified') with micronutrients using plant breeding and/or transgenic strategies, because micronutrient enrichment traits exist within their genomes that can to used for substantially increasing micronutrient levels in these foods without negatively impacting crop productivity. Furthermore, 'proof of concept' studies have been published using transgenic approaches to biofortify staple crops (e.g. high beta-carotene 'golden rice' grain, high ferritin-Fe rice grain, etc). In addition, micronutrient element enrichment of seeds can increase crop yields when sowed to micronutrient-poor soils, assuring their adoption by farmers. Bioavailability issues must be addressed when employing plant breeding and/or transgenic approaches to reduce micronutrient malnutrition. Enhancing substances (e.g. ascorbic acid, S-containing amino acids, etc) that promote micronutrient bioavailability or decreasing antinutrient substances (e.g. phytate, polyphenolics, etc) that inhibit micronutrient bioavailability, are both options that could be pursued, but the latter approach should be used with caution. The world's agricultural community should adopt plant breeding and other genetic technologies to improve human health, and the world's nutrition and health communities should support these efforts. Sustainable solutions to this enormous global problem of 'hidden hunger' will not come without employing agricultural approaches.

Arabidopsis thaliana transcription factors bZIP19 and bZIP23 regulate the adaptation to zinc deficiency

“…Zinc deficiency afflicts up to 40% of the world's human population, mainly in developing countries where people depend on cereal-rich diets for sustenance (29,30). Biofortification of crops with zinc, using plant breeding and other genetic technologies, offers a sustainable solution to this global problem (31,32). Achieving a plant-based solution to alleviate zinc deficiency has thus far been hampered by insufficient knowledge on the mechanisms and regulation of the zinc homeostasis network in plants (32,33).…”

Sequence related amplified polymorphism (SRAP) analysis for genetic diversity and micronutrient content among gene pools in mungbean [Vigna radiata (L.) Wilczek]

“…Biofortification through genetic manipulation of staple food crops is the most promising strategy to alleviate micronutrient deficiency (Tiwari et al 2010). There are several approaches to biofortify crops, including agronomic biofortification (Cakmak 2008), genetic engineering (Brinch-Pederson et al 2007) and conventional or molecular breeding (Welch and Graham 2004). Among these approaches, breeding for micronutrient enhancement has been considered as the best strategy due to low and nonrecurrent expenditure and higher public acceptability (Nestel et al 2006;Ortiz-Monasterio et al 2007).…”

Biofortified crops to alleviate micronutrient malnutrition

“…Even though insufficient intake of any essential micronutrient will result in metabolic impairment of individuals, potentially increasing morbidity and death rates, numerous national and regional surveys have identified iron, vitamin A and iodine as most vital for global human health, among almost 30 essential micronutrients [13]. Micronutrients such as zinc and folate, are acquiring similar status as statistics accumulate (see Box 1).…”