Advances in Genomic Interventions for Wheat Biofortification: A Review

Abstract

Wheat is an essential constituent of cereal-based diets, and one of the most significant sources of calories. However, modern wheat varieties are low in proteins and minerals. Biofortification is a method for increasing the availability of essential elements in the edible portions of crops through agronomic or genetic and genomic interventions. Wheat biofortification, as a research topic, has become increasingly prevalent. Recent accomplishments in genomic biofortification could potentially be helpful for the development of biofortified wheat grains, as a sustainable solution to the issue of “hidden hunger”. Genomic interventions mainly include quantitative trait loci (QTL) mapping, marker-assisted selection (MAS), and genomic selection (GS). Developments in the identification of QTL and in the understanding of the physiological and molecular bases of the QTLs controlling the biofortification traits in wheat have revealed new horizons for the improvement of modern wheat varieties. Markers linked with the QTLs of desirable traits can be identified through QTL mapping, which can be employed for MAS. Besides MAS, a powerful tool, GS, also has great potential for crop improvement. We have compiled information from QTL mapping studies on wheat, carried out for the identification of the QTLs associated with biofortification traits, and have discussed the present status of MAS and different prospects of GS for wheat biofortification. Accelerated mapping studies, as well as MAS and GS schemes, are expected to improve wheat breeding efficiency further.

The role of bread in the UK diet: An update

“…Importantly though, the introduction of selenium‐biofortified wheat could, without monitoring, care and planning, result in toxicity among individuals with high intakes and therefore would require careful consideration (Bañuelos et al 2017). Another area of interest for biofortification is the anthocyanin content of wheat (Saini et al 2020), a class of polyphenols that gives plant foods such as berries their colour. Coloured wheat (purple, blue, red, black) which naturally has higher concentrations of anthocyanins, and also higher micronutrient contents in some lines compared with amber wheat, can be used to produce high yield coloured wheat lines (Ficco et al 2014; Sharma et al 2018).…”

“…While zinc‐biofortified wheat lines have been successfully developed by identifying and exploiting natural genetic variation and through the use of fertilisers, both techniques have proven to be less effective for significantly increasing iron in wheat. However, genetic modification through transgenesis has been used to produce wheat containing bioavailable iron and zinc in the starchy endosperm (Balk et al 2019; Saini et al 2020). While transgenesis is currently unacceptable to some, in the future this approach may be viewed more favourably if it can deliver nutritional benefits that cannot be attained using conventional breeding methods; for example, increases in iron and zinc that are not associated with phytate have been achieved in wheat (Balk et al 2019), in a compartment that would not be lost during milling (Shewry 2016).…”

Applying genomic resources to accelerate wheat biofortification

“…This QTL, Gpc-B1, conferred an 18% increase in iron and a 12% increase in zinc content, and the gene underlying the QTL was identified to be the NAC transcription factor NAM-B1 (Distelfeld et al 2007;Uauy et al 2006). Many QTL studies have been conducted to explore the genetic regions for iron and zinc contents in wheat, which have been recently reviewed elsewhere (Garcia-Oliveira et al 2018;Saini et al 2020). The QTLs identified within each study were often different from each other due to differences in populations, environments and marker sets, which greatly affect the location and precision of the QTL identified.…”

“…Due to the importance of this topic, there are many recent review articles (e.g. Cakmak and Kutman 2018;Connorton and Balk 2019;Ludwig and Slamet-Loedin 2019;Saini et al 2020), which summarise agronomic and genetic Associate editor: Alison Bentley approaches to wheat biofortification. However, limited attention has been paid to how the recent developments in wheat genomics can be applied specifically to biofortification.…”

Breeding for Biofortification Traits in Rice: Means to Eradicate Hidden Hunger

“…Biofortification is a promising, cost-effective, agricultural strategy to improve the nutritional status of the world's undernourished populations. Strategies for biofortification based on crop breeding, targeted genetic manipulation, and/ or mineral fertiliser application have great potential to address human mineral malnutrition [70][71][72]. Developing biofortified food crops with improved nutrient content such as increased content of iron, zinc, Se, and provitamin A provides adequate levels of these and other such micronutrients that are often lacking in developed and developing diets.…”