Golden (Beta Carotene) Rice

Kui Tang

Vitamin A Crisis

● Rice, Oryza sativa, is vitamin A deficient.● 124 million suffer from vitamin A deficiency

annually (1). Many eat rice as a staple.● 500,000 cases of dry eyes and blindness (1).

Also major factor in disease and childhood death (3).

● Vitamin A rice is simple, inexpensive solution.

Prevalence of Vitamin A Deficiency

History● Created by Ingo

Potrykus, Swiss from 1992-2000 (right).

● Cross-bred to local rice strains in Philippines, Taiwan.

● Field trials at Louisiana State University reveal 3-4 times more β-carotene than greenhouse.

History● First generation proof of concept only; 1.6µg/g of

β-carotene insufficient (3).● Second generation used psy gene from maize and

rice genes. Produced 31 µg/g β-carotene. Exactly the required amount (3).

Overview

● Two steps of β-carotene pathway are missing in the endosperm.

● Recombining two genes completes the pathway.

● GGPP is precursor for many important pigments.

Genetics

● Rice can naturally produce β-carotene in leaves for photosynthesis, but not nutritionally significant amount.

● Golden rice produces it in endosperm (grain).

● Recombine two β-carotene synthesis genes under endosperm glutelin promoter (3):

– phytoene synthase (psy) from daffodil;

– crt1 from Erwinia uredovora.● Unique because researchers engineered entire biosynthesis

pathway from geranylgeranyl diphosphate to β-carotene (2).

Genome

Genetics● Geranylgeranyl

diphosphate produced naturally in plastids.

● Recombinant genes convert to lycopene.

● Native lycopene cyclase (lyc) gene converts lycopene to β-carotene.

● Excess lycopene creates yellow color.

The carotene synthesis biopathway, occurring in the endosperm.

Engineered Pathway

Criticism

● Genetic engineering is a fundamentally flawed approach to solving malnutrition.

● Promotes loss of biodiversity: corporate monoculture of rice destroys ability to plant a variety of foods, which is the best way to combat malnutrition (4), (5).

● World bank admits replanting local plants is more effective (4).

● Only a balanced diet can provide nutrition. Vegetables, not rice, should be the focus (5).

● Monsanto, Novartis, Astra-Zeneca own patents. They may extort money in the future.

Legal Issues● 4 patents, 70 patent

claims.● EEC funding required

giving rights to industry.● Licensed to farmers in

developing countries who earn < $10,000/yr

● Some claim main purpose of Golden Rice is to restore political respectability to GMO.

Conclusion● Golden Rice can save millions through Vitamin A provision

—the genetic engineering equivalent of iodized salt or fluorinated water (2).

● This would be one of the first GMO crops to help consumers instead of merely farmers—and help them to not die.

● Second generation produces requisite amounts of β-carotene. Old arguments about not providing enough are void.

● Alternate foods (fruits, vegetables) may not be available, hence consuming Golden Rice is essential.

● Genes breed well into local rice varieties.

● Intellectual property issues may still need to be worked out, but free licenses are available now and the corporations have pledged humanitarian efforts (4).

Bibliography(1) Humphrey, J.H., West, K.P. Jr, and A. Sommer. “Vitamin A deficiency and attributable

mortality in under-5-year-olds.” WHO Bulletin. 70 (1992): 225-232.

(2) “Golden Rice.” Wikipedia. 23 Jan 2008. 24 Jan. 2008 <http://en.wikipedia.org/wiki/Golden_rice>.

(3) “Golden Rice.” Golden Rice Humanitarian Board. 2007. 23 Jan. 2008 <http://www.goldenrice.org/>.

(4) Shiva, Vandana. “The Golden Rice Hoax—When Public Relations Replaces Science.” 23 Jan. 2008 <http://online.sfsu.edu/~rone/GEessays/goldenricehoax.html>.

(5) “‘Golden Rice’ and Vitamin A Deficiency.” 23 Jan. 2008 <http://www.foe.org/safefood/rice.html>.

(6) Nash/Zurich, Madeline J. “Grains of Hope.” Time 31 Jul. 2000: (Internet, n.pag.).

(7) Beyer, Peter, et al. “Golden Rice: Introducing the ß-Carotene Biosynthesis Pathway into Rice Endosperm by Genetic Engineering to Defeat Vitamin A Deficiency.” The Journal of Nutrition. 132 (2002): 506S-510S.