Towards a Solution for Hidden Hunger: Folate Biofortification of Crop Plants

Improving nutritional health is one of the major socio-economic challenges of the 21st century, especially with the continuously growing and aging world population. Biofortification holds great promises to tackle nutrient deficiencies by providing balanced levels of vitamins and micronutrients in staple crops. Folate deficiency is an important and underestimated problem of micronutrient malnutrition affecting billions of people worldwide. Several countries are adapting policies to fight folate deficiency, mostly by fortifying foods with folic acid. However, there is growing concern about this practice, calling for alternative or complementary strategies. Additionally, fortification programs are often inaccessible to remote and poor populations, where folate deficiency is most prevalent. Enhancing folate content in staple crops by metabolic engineering is a promising, cost-effective strategy to eradicate folate malnutrition worldwide. Over the past decade, major progress has been made in this field. Nevertheless, engineering strategies have thus far been implemented on few plant species only, and need to be transferred to other, highly consumed staple crops to maximally reach target populations. Moreover, successful engineering strategies appear to be species-dependent, hence need to be tuned to biofortify different staple crops with folate. Last but not least, several factors affecting vitamin stability lower the beneficial effect of metabolic engineering. We recently adapted our engineering strategy to further increase folate levels in biofortified rice, together with an enhancement of folate stability (Blancquaert et al., Nature Biotechnology, 33:1076–1078, 2015).