|Yin, Shi-An -|
|Wang, Yin -|
|Qin, Jian -|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2010
Publication Date: N/A
Technical Abstract: Golden Rice (GR) is a transgenic product engineered to produce beta-carotene in the rice endosperm. It has been developed as a means to combat vitamin A malnutrition, which exists throughout much of the developing world (especially in rice eating populations) and can lead to blindness, increased susceptibility to various diseases, and higher incidence of childhood mortality. To determine the vitamin A value (ie, beta-carotene conversion efficiency) of this rice, GR beta-carotene was intrinsically labeled with deuterium, a non-radioactive stable isotope of hydrogen, by growing plants in a nutrient solution containing 23% heavy water (deuterium oxide). The GR beta-carotene was enriched with deuterium with the highest abundance isotopomer peak at M+9. Human subjects were given a known amount of an oil capsule of 13C-retinyl acetate as a reference dose, in addition to a single serving of deuterium-labeled GR. Serum samples collected from the subjects were analyzed using GC/ECNCI-mass spectrometry for the enrichments of labeled retinol by monitoring the isotopomers M+5 (derived from GR) and M+10 (derived from 13C-retinyl acetate). By using the response to the dose of 13C-retinyl acetate as reference, the conversion efficiency of GR beta-carotene could be determined. The results of two studies, one involving healthy adults, and the other a comparative study with children (replete or marginally deficient in vitamin A), will be presented. Results will be discussed in the context of GR's potential contribution to the alleviation of vitamin A deficiency and the maintenance of population-based vitamin A adequacy. Discussion will also focus on how this information has been used for event selection and in strategic planning to move this technology into locally adapted cultivars.