Plant scientists from ETH Zurich and the University of Geneva have engineered a cassava plant that produces extra vitamin B6 in its roots and leaves, which could help alleviate deficiencies of the vitamin in African populations.
Cassava is one of the most important staple foods in many sub-Saharan African nations. The starchy roots are harvested as food, as are the leaves. Both parts must be thoroughly cooked to remove the plant's toxic cyanide compounds.
In its natural state, Cassava contains only small amounts of vitamin B6, but scientists have discovered a way to genetically modify the plant so that it produces much more vitamin B6.
A deficiency in vitamin B6 can cause cardiovascular and nervous system diseases.
"Using the improved variety, only 500 grams of boiled roots or 50 grams of leaves per day is sufficient to meet the daily vitamin B6 requirement," Wilhelm Gruissem, professor of plant biotechnology at ETH Zurich, said.
The basis for the new genetically modified cassava variant was developed by Professor Teresa Fitzpatrick at the University of Geneva, who discovered biosynthesis of vitamin B6 in model plant thale cress (Arabidopsis thaliana). Two enzymes, PDX1 and PDX2, are involved in the synthesis of the vitamin. With the introduction of the corresponding genes for the enzymes into the cassava genome, the researchers produced several new cassava lines that contained increased levels of vitamin B6.
"Our strategy shows that increasing vitamin B6 levels in an important food crop using Arabidopsis genes is stable, even under field conditions," Hervé Vanderschuren, who led the cassava research program at ETH Zurich and recently became a professor of plant genetics at the University of Liège, said.
