Golden rice, genetically biofortified to contain beta-carotene (pro-vitamin A), has shown its efficiency in uptake and conversion in the initial nutritional study with humans. Tests indicate the body can absorb enough beta-carotene from 200g to 300g of golden rice per day to prevent vitamin A deficiency, which impairs eyesight and causes over a million deaths worldwide each year.
This breakthrough was one of the first aimed at using genetic modification techniques to improve the nutritional content of staple foods. Golden rice was created by Prof Ingo Potrykus of the Institute of Plant Sciences at the Swiss Federal Institute of Technology, working with Prof Peter Beyer of the University of Freiburg. The objective was to improve rice as staple food for over a billion people in Asia. The project has taken a long time due to the novelty of the approach.
The first hurdle was to insert a gene from yellow daffodil into the rice genetic system, but this modification in 1999 produced inadequate levels of the beta-carotene. In the second round, this gene was replaced with a yellow maize gene that increased beta-carotene by over 20 times, resulting in the Golden Rice 2 version. From here it became necessary to develop a number of isotope-marked rice lines to enable precise conversion measurements.
Tufts University in the US, funded by the US’s National Institute of Health, conducted feeding studies and measured uptake and conversion to vitamin in humans. he next step, planned for 2008, will be nutritional studies on some 50 vitamin A-deficient children. In the meantime plant breeders are already breeding this beneficial trait into rice varieties adapted to South East Asia. – Wynand van der Walt ([email protected]). Source: Ornamental Bioscience website, September 2006.