Compositional Analysis of Genetically Engineered GR2E “Golden Rice” in Comparison to That of Conventional Rice

Abstract

Compositional analyses were performed on samples of rice grain, straw, and derived bran obtained from golden rice event GR2E and near-isogenic control PSBRc82 rice grown at four locations in the Philippines during 2015 and 2016. Grain samples were analyzed for key nutritional components, including proximates, fiber, polysaccharides, fatty acids, amino acids, minerals, vitamins, and antinutrients. Samples of straw and bran were analyzed for proximates and minerals. The only biologically meaningful difference between GR2E and control rice was in levels of β-carotene and other provitamin A carotenoids in the grain. Except for β-carotene and related carotenoids, the compositional parameters of GR2E rice were within the range of natural variability of those components in conventional rice varieties with a history of safe consumption. Mean provitamin A concentrations in milled rice of GR2E can contribute up to 89–113% and 57–99% of the estimated average requirement for vitamin A for preschool children in Bangladesh and the Philippines, respectively.

Marker-free carotenoid-enriched rice generated through targeted gene insertion using CRISPR-Cas9

“…In the dehusked, polished seeds from 48A-7, the βcarotene content was 7.90 ± 0.19 μg g −1 dry weight (Supplementary Table 4), while no significant amount of β-carotene was detected in the dehusked, polished Kitaake seeds. The observed β-carotene content in 48A-7 is slightly lower than that of the GR2 transformation event GR2E in japonica rice variety Kaybonnet under greenhouse conditions (9.22 μg g −1 dry weight) 30 , and comparable to the higher end of the range of β-carotene content measured in field-grown indica rice variety PSB Rc82 (1.96-7.31 μg g −1 dry weight) 32 . The difference in the β-carotene content observed in these studies may be due to the differences in growth conditions, genomic positional effects, and/or postharvest decay of the carotenoids 45 , the rate of which varies among cultivars 46 .…”

“…Because of the valuable socio-economic impact conferred by the Golden Rice 2 (GR2) cassette, its availability, and the clear phenotype it confers 30 , we chose to modify this cassette and use it as the donor DNA to assess the efficiency of marker-free targeted insertion in rice. Rice varieties carrying the Golden Rice 1 (GR1) and the GR2 cassettes accumulate carotenoids in the grain [30][31][32] . The endosperm of GR1 and GR2 is golden in color 30,31 , compared with the white endosperm observed in most conventional rice varieties.…”

Carotenoid biofortification in crop plants: citius, altius, fortius

“…Similarly, intake of biofortified orange maize resulted in a significant improvement in vitamin A status, indicated by an increase in pupillary responsiveness, of marginally vitamin A deficient children [255,261]. Finally, Golden Rice has the potential to fulfill up to 89−113% and 57−99% of the estimated average requirement for vitamin A for preschool children in Bangladesh and the Philippines, respectively [258].…”

“…None of the five major staple crops (wheat, corn, rice, potato, cassava) can provide 25% of the RDA, which is sufficient to prevent vitamin A deficiency [44]. There are several studies on the bioavailability, bioaccessibility and retinol equivalency of carotenoids from biofortified crops (reviewed in: [44,[256][257][258]. The bioaccessibility of -carotene from biofortified cassava, melon, sorghum and potato is comparable with that from the corresponding original varieties [44].…”

Rice Biofortification: High Iron, Zinc, and Vitamin-A to Fight against “Hidden Hunger”

“…Detailed molecular characterization of GR [95], field performance analysis [102], and metabolic and proteomic analyses [103] have been performed in different laboratories worldwide, and have been found to be safe for human consumption [104]. Recently in 2018, three renowned international food safety regulatory agencies: Food Standards Australia New Zealand, Health Canada, and the United States Food and Drug Administration recommended GR for commercialization and gave positive feedback on it (www.irri.org/golden-rice, access on 20 April 2019).…”