Iron and protein biofortification of cassava: lessons learned.
Over two hundred and fifty million Africans rely on the starchy root crop cassava (Manihot esculenta) as their primary source of calories. Cassava roots, however, have the lowest protein:energy ratio of all the world's major staple crops. Furthermore, a typical cassava-based diet provides less than 10-20% of the required amounts of iron, zinc, vitamin A and vitamin E. The BioCassava Plus program employed modern biotechnologies to improve the health of Africans through development and delivery of novel cassava germplasm with increased nutrient levels. Here we describe the development of molecular strategies and their outcomes to meet minimum daily allowances for protein and iron in cassava based diets. We demonstrate that cyanogens play a central role in cassava nitrogen metabolism and that strategies employed to increase root protein levels result in reduced cyanogen levels in roots. We also demonstrate that enhancing root iron uptake has an impact on the expression of genes that regulate iron homeostasis in multiple tissues. These observations demonstrate the complex metabolic interactions involved in enhancing targeted nutrient levels in plants and identify potential new strategies for further enhancing nutrient levels in cassava.
Phycal Sugar LLC, 1005 N Warson Rd., St. Louis, MO 63132, USA.
Elisa
E
Leyva-Guerrero
Narayanan N
NN
Narayanan
Uzoma
U
Ihemere
Richard T
RT
Sayre
D004044:Dietary Proteins; D005527:Food, Fortified; D006801:Humans; D019266:Iron, Dietary; D002365:Manihot / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development; D018517:Plant Roots / Q000737:chemistry; D030821:Plants, Genetically Modified / Q000737:chemistry* / Q000254:growth & development; D014801:Vitamin A / Q000032:analysis; D014810:Vitamin E / Q000032:analysis; D015032:Zinc / Q000032:analysis
D004044:Dietary Proteins; D019266:Iron, Dietary; D014801:Vitamin A; D014810:Vitamin E; D015032:Zinc