Abstract
Less than 10% of the estimated average requirement (EAR) for iron and zinc is provided by consumption of storage roots of the staple crop cassava (Manihot esculenta Crantz) in West African human populations. We used genetic engineering to improve mineral micronutrient concentrations in cassava. Overexpression of the Arabidopsis thaliana vacuolar iron transporter VIT1 in cassava accumulated three- to seven-times-higher levels of iron in transgenic storage roots than nontransgenic controls in confined field trials in Puerto Rico. Plants engineered to coexpress a mutated A. thaliana iron transporter (IRT1) and A. thaliana ferritin (FER1) accumulated iron levels 7–18 times higher and zinc levels 3–10 times higher than those in nontransgenic controls in the field. Growth parameters and storage-root yields were unaffected by transgenic fortification in our field data. Measures of retention and bioaccessibility of iron and zinc in processed transgenic cassava indicated that IRT1 + FER1 plants could provide 40–50% of the EAR for iron and 60–70% of the EAR for zinc in 1- to 6-year-old children and nonlactating, nonpregnant West African women.
Highlights
Less than 10% of the estimated average requirement (EAR) for iron and zinc is provided by consumption of storage roots of the staple crop cassava (Manihot esculenta Crantz) in West African human populations
We previously found that overexpression of the A. thaliana vacuolar iron transporter VIT1 in cassava results in a three- to four-times increase in iron concentration in storage roots compared with the concentrations in nontransgenic controls under greenhouse conditions[17]
Data from field-grown VIT1 and IRT1 + FER1 transgenic lines in Puerto Rico field trials (2014–2017) indicate that both technologies result in cassava storage roots and foodstuffs with elevated iron and zinc levels that may beneficially affect the nutritional status of consumers
Summary
Less than 10% of the estimated average requirement (EAR) for iron and zinc is provided by consumption of storage roots of the staple crop cassava (Manihot esculenta Crantz) in West African human populations. We report that coexpression of a mutant A. thaliana iron transporter (IRT1)[18] and ferritin (FER1) generates transgenic cassava plants that accumulate iron and zinc in storage roots to substantial levels in the human diet. When assessed as whole plants, IRT1 + FER1 transgenic lines, compared with nontransgenic controls, showed significantly higher (P ≤ 0.01) total iron and zinc content, by up to five and two times, respectively (Supplementary Fig. 3a,b).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
