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Golden Rice

Golden rice is a variety of rice (Oryza sativa) produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A, in the edible parts of rice.It is intended to produce a fortified food to be grown and consumed in areas with a shortage of dietary vitamin A, a deficiency which each year is estimated to kill 670,000 children under the age of 5 and cause an additional 500,000 cases of irreversible childhood blindness. Rice is a staple food crop for over half of the world's population, providing 30–72% of the energy intake for people in Asian countries, and becoming an effective crop for targeting vitamin deficiencies.

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Golden Rice

  1. 1. Golden rice “This rice could save a million kids a year D r. P a v an J K u n d u r A ssistant P rofessor D ept of B iotechnology and M icrobiology P C Jabin S cience C ollge H ubballi
  2. 2. Why Golden ...Rice? • Rice is a staple food crop for over half of the world's population, • Providing 30–72% of the energy intake for people in Asian countries • 124 million children are deficientin vitamin-A. • 1-2 million deaths annually (1-4years). • 0.25-0.5million deaths (5-10years) UNICEF. • In 2005, 190 million children and 19 million pregnant women, in 122 countries, • were estimated to be affectedby V’A’D • White rice lacks: beta-carotene,which is converted into vitamin A in the body.
  3. 3. Symptoms of a Provitamin-a-free diet • Night-blindness shortage of dietary vitamin A, a deficiency which each year is estimated to kill 670,000 children under the age of 5 and cause an additional 500,000 cases of irreversible childhood blindness. • Xerophthalmia • Fatal susceptibility to childhood diseases (e.g. measles) and general infections (diarrhoea, respiratory diseases). Solution :- • For many countries, the infrastructuredoesn’t exist todeliver vitamin pills. • Improved vitamin-Acontentin major staple consumedcrops an attractive alternative to fight micronutrient deficiencies.
  4. 4. Golden rice is a variety of rice (Oryza sativa) produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A, in the edible parts of rice. Golden rice is a genetically engineered by the International Rice Research Institute ( IRRI - a not for profit research organization based in the Philippines) as a potential new food-basedapproach to improve vitamin A status. Ingo Potrykus
  5. 5. • Idea first discussed at International Conference at IRRI in Philippines in 1984. • 1999 Team of scientists, including Ingo Potrykus, Swiss Federal Institute of Technology, successfully genetically engineerrice to produce carotenoids,precursors to Vitamin-A. • The hype begins: 2000 Time magazinecover story:“This rice could save a million kids a year.” • May 2000: Adrian Dubock (Zeneca, now Syngenta):“One month delay = 50,000 blind children [a] month.” • June 29, 2000 US special CongressionalForum, “Can Biotechnology Solve World Hunger?” Invitation stated, “ ‘golden rice’, which has been modified to include certain vitamins……….Is already saving the sight of thousands of children in the poorest parts of Asia.”
  6. 6. IPPIsopentenyl diphosphate  -carotene (vitaminAprecursor) Geranyl diphosphate Phytoene synthase Phytoene Phytoene desaturase ξ-carotene desaturase Lycopene Lycopene-beta-cyclase Problem: Rice lacks these enzymes Normal Vitamin A “Deficient” Rice  -carotene pathway in Rice
  7. 7. • Golden Rice technology is based on the simple principle that rice plants possess the whole machinery to synthesis of β-carotene, and while this machinery is fully active in leaves, parts of it are turned off in the grain endosperm. • By adding only two genes, a plant phytoene synthase (psy) and a bacterial phytoene desaturase (crt I), the pathway is turned back on and β-carotene consequently accumulates in the grain. • Golden rice was created by transforming rice with only two β-carotene biosynthesis genes: 1) psy (Phytoene synthase) from daffodil (Narcissuspseudonarcissus) 2) crtI (Carotene desaturase) from the soil bacteriumErwiniauredovora Golden Rice technology
  8. 8. Gene construct used to generate Golden Rice-1. RB, T-DNA right border sequence; Glu, rice endosperm-specific glutelin promoter; tpSSU, pea ribulose bis-phosphate carboxylase small subunit transit peptide for chloroplast localisation; crtI Carotene desaturase from the soil bacterium Erwinia uredovora; nos, nopaline synthase terminator; Psy, phytoene synthase gene from Narcissus pseudonarcissus (GR1) or Zea mays (GR2); Ubi1, maize polyubiquitin promoter; Pmi, phosphomannose isomerase gene from E. coli for positive selection (GR2); LB, T-DNA left bordersequence. • Lycopene is then cyclized to beta-carotene by the endogenous cyclase in Golden Rice. (The insertion of a lcy (lycopene cyclase) gene was thought to be needed, but further research showed it is already being produced in wild-type rice endosperm.)
  9. 9. • The psy and crtI genes were transformed into the rice nuclear genome and placed under the control of an endosperm-specific promoter, so they are only expressed in the endosperm. • The exogenous lcy gene has a transit peptide sequence attached so it is targeted to the plastid, where geranylgeranyl diphosphate formation occurs. • The end product of the engineered pathway is lycopene, but if the plant accumulated lycopene, the rice would be red. Recent analysis has shown the plant's endogenous enzymes process the lycopene to β-carotene in the endosperm, giving the rice the distinctive yellow color for which it is named.. • The original golden rice was called SGR1, and under greenhouse conditions it produced 1.6 µg/g of carotenoids.
  10. 10. The Golden Rice: Solution IPP  -carotene (vitaminAprecursor) Lycopene-beta-cyclase Geranylgeranyldiphosphate Daffodil gene Phytoene synthase Phytoene Phytoene desaturase Single bacterial gene; performs both functions ξ-carotene desaturase Lycopene Daffodil gene -Carotene Pathway GenesAdded VitaminA Pathway is complete andfunctional Golden Rice Presence of pro-vitamin -A gives rice grains a yellowish-orange color,thus,thename ‘GoldenRice.’
  11. 11. Originial Golden Rice (GR1) does not produce enough ß-carotene (Provitamin A); it produces “only 1.6 μg/gm of carotenoids; a child would have to eat more than 10kg/day to get sufficient dose”. Unexpected effect: GR1 was supposed to produce lycopene (as in tomatoes) and so be bright red; instead, it produced ß-carotene due to unexpected metabolicpathway 37 µg/g of carotenoids). • Toreceive the RecommendedDietaryAllowance(RDA), it is estimated that peoplewho eat about 75g of golden rice perday. In June2005, researcherPeter Beyer received funding from theBill and Melinda Gates Foundation to further improve golden rice by increasing the levels of or the bioavailabilityof pro-vitamin A, vitamin E, iron, and zinc, and to improve protein quality. Golden Rice 1(GR1) : Specifications
  12. 12. Golden Rice 2 (GR2) : Specifications • In 2005, Syngenta, produced a variety of golden rice called "Golden Rice 2". • They combined the phytoene synthase(psy) gene from maize with carotene desaturase (crt1) from the original Golden rice-1. • Both genes are under endosperm specific promoter control and the mannose act as selectablemarker. • Golden rice 2 produces 23 times more carotenoids than golden rice (up to 37 µg/g), and preferentially accumulates β- carotene (up to 31 µg/g of the 37 µg/g of carotenoids). • To receive the Recommended Dietary Allowance (RDA), it is estimated that people who eat about 75g of golden rice per day. • In June 2005, researcher Peter Beyer received funding from the Bill and Melinda Gates Foundation to further improve golden rice by increasing the levels of or the bioavailability of pro-vitamin A, vitamin E, iron, and zinc, and to improve protein quality.
  13. 13. Controversy: Golden Rice…..Isit worth the risks? • Critics of genetically engineered crops have raised various concerns. • Health • May cause allergies or fail to perform desiredeffect. • Supply does not provide a substantial quantity as the recommended daily intake.  Environment • Loss of Biodiversity. May become a super weed and endanger theexistence of natural rice plants. • Genetic contamination of natural, global staplefoods. • Gene flow from GM to non-GM fieldcrops.  Culture • Some peopleprefer to cultivate and eat only white rice based ontraditional values and spiritual beliefs on Veg. orNon-Veg. • Intervention in “Godscreation”.
  14. 14. An early issue was that “golden rice originally did not have sufficient vitaminA”. “The speed at which vitamin A degrades once the rice is harvested”, and “how much remains after cooking are contested.” Greenpeace opposes the use of any patented genetically modified organismsin agriculture and opposes the cultivation of golden rice, claiming “it will open the door to more widespread use ofGMOs.”. Vandana Shiva, an Indian anti-GMO activist, Shiva claimed “these problems could be amplified by the corporate control of agriculture.” • Other groups argued that a varied diet containing foods rich in beta carotene such as sweet potato, leafy green vegetables and fruit would provide children with sufficient vitaminA. • Keith West of Johns Hopkins, “foodstuffs containing vitamin A are either unavailable, or only available at certain seasons, or that they are too expensive for poor familiesin underdeveloped countries”.
  15. 15. IRRI also assures the public that “Golden Rice” will be available to farmers and consumers only after it has been determined to be safe for humans, animals, and the environment and authorized for propagation and consumption by the appropriate regulatory authorities. Therefore, “Golden Rice”, if and when released, will be deemed to be as safe as other rice. WHO, report says These assessments found no risk to human health”. The Food Allergy Resource and Research Program of the University of Nebraska (2006) that showed “the proteins from the new genes in Golden Rice did not show any allergenic properties”. In 2009, research results of a clinical trial of Golden Rice with adult volunteers from the USA were published in the American Journal of Clinical Nutrition. It concluded that "β- carotene derived from Golden Rice is effectively converted to vitamin A in humans is a safe". In August 2012, Tufts University and others published new research on Golden Rice in the American Journal of Clinical Nutrition showing that “the β-carotene produced by Golden Rice is as good as β- carotene in oil at providing vitamin A to children”. Clinical trials / food safety and nutrition research
  16. 16. The Conversation US-07-Feb-2020 The Conversation US-07-Feb-2020
  17. 17. “Public sentiment is everything. With public sentiment, nothing can fail. Without it, nothing can succeed.” – AbrahamLincoln.

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