Iron biofortification of maize grain

Abstract

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world's population suffer from iron deficiency-induced anaemia, 80% of which are in developing countries. The consequences of iron deficiency include increased mortality and morbidity rates, diminished cognitive abilities in children and reduced labour productivity, which in turn stagnates national development. The developed world has made tremendous success in alleviating nutrient deficiencies through dietary diversification, food product fortification, improved public health care and supplementation. In developing countries, these strategies are often expensive and difficult to sustain, especially in rural areas. The rural poor typically consume what they grow and are dependent upon a small number of staple crops for the vast majority of their nutrition. Therefore, genetic improvement of staple crops (biofortification) is the most cost-effective and sustainable solution to this global health problem. In this study, we describe a strategy to enhance iron nutritional quality in maize using a human cell culture (Caco-2)-based bioassay as a phenotyping tool to guide genetic analysis of the trait. We also report validation of this approach using an animal feeding study.

RETRACTED ARTICLE: High bioavailablilty iron maize (Zea mays L.) developed through molecular breeding provides more absorbable iron in vitro (Caco-2 model) and in vivo (Gallus gallus)

“…Maize ( Zea mays L.) is widely consumed in developing countries and provides energy, vitamins and minerals [8-15]. However, a major cause of Fe deficiency is poor intake of Fe, due to low bioavailability from plant-based diets containing mineral absorption inhibitors as polyphenols and phytates.…”

“…Research into the genetic basis for Fe nutritional quality in maize has established the potential for Fe biofortification, as Fe concentration and bioavailability are under genetic control and have demonstrated potential for improvement [8,9]. Previously, we utilized quantitative trait locus (QTL) mapping to characterize the genetic complexity of Fe concentration and bioavailability in maize [9,20,21].…”

“…These derivatives were selected to create a maximal degree of contrast in predicted Fe bioavailability. With High and Low varieties in both parental backgrounds, these High-Fe and Low-Fe bioavailability hybrids are essentially identical for all parts of their genomes (all features of grain quality would be expected to be the same) except the 3 QTL-containing regions on maize chromosomes 3, 6 and 9 [8,9]. Preliminary in vivo study indicated that the predictions made with the Caco-2 bioassay were valid for predicting Fe bioavailability [8].…”

“…With High and Low varieties in both parental backgrounds, these High-Fe and Low-Fe bioavailability hybrids are essentially identical for all parts of their genomes (all features of grain quality would be expected to be the same) except the 3 QTL-containing regions on maize chromosomes 3, 6 and 9 [8,9]. Preliminary in vivo study indicated that the predictions made with the Caco-2 bioassay were valid for predicting Fe bioavailability [8]. The equivalence of the High-Fe and Low-Fe bioavailability varieties for grain Fe concentration, flowering time, and other characteristics except Fe bioavailability suggests that our strategy of creating these hybrids and the focus on the effect of the 3 major QTL was successful [8,9].…”

The Combined Application of the Caco-2 Cell Bioassay Coupled with In Vivo (Gallus gallus) Feeding Trial Represents an Effective Approach to Predicting Fe Bioavailability in Humans

“…For example, research has demonstrated that the Caco-2 cell bioassay [20] is a fast and cost effective approach to screening of hundreds of samples and prior to the selection of the most promising lines to be assessed in vivo [21]. Subsequent feeding trials of the selected lines confirmed the enhanced Fe bioavailability developed via the in vitro screening [22]. …”