Genetic engineering and the food we eat*

Transcription

1 Genetic engineering and the food we eat* Prof. Daniel Chamovitz Tel Aviv University *and the clothes we wear, and the medicines we take, and gasoline we burn

2 Problem #1: World Population is exploding billion

3 Problem #2: Arable land is decreasing Arable land is decreasing by 100,000 km 2 per year Projections are that while 24% of the earth s surface today is arable, less than 20% will be arable by 2050!

4 Problem #3: Gains in yield are decreasing World cereal production per person is 2000 kcal / day To maintain this level, yields have to increase 36% by 2025! And this with: Less land Less water Less phosphates Hotter world Corn in west Africa

5 Result Still, About 800 million people go hungry each day!

6 Partial Solution: Genetic engineering

7 (Psychological) Barriers to Genetically Modified Food 1. Its not natural

8 Tomatoes: What s natural? Natural (found in the wild) Resistant to diseases Resistant to all pests Poisonous 100 s of years of breeding Sensitive to diseases Sensitive to pests Delicious

9 Corn: What s natural?

10 Human intervention has invented all our cultivated foods!

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12 Tomatoes: Classic Breeding X

13 Tomatoes: Classic Breeding X X

14 Tomatoes: Breeding X

15 Tomatoes: Molecular breeding (genetic engineering)

16 How do we do this? Agrobacterium Agrobacterium

17 How do we do this? genetic engineering Gene switch Agrobacterium engineered Agrobacterium transformed Plant cell (genetically engineered)

18 DNA gun

19 Proof of concept

20 How can this technology be used for the common good?

21 Vitamin A deficiency among children Blind: 0.5 million Xerophthalmia: 3.1 million Night blind: 13.5 million Inadequate vitamin A: 231 million

22 Why so much vitamin A deficiency? Rice has no vitamin A (beta-carotene) Rice is the primary food source for the majority of the world s population Solution: put the genes for beta- carotene into rice

23 The Tale of Golden Rice Rice seeds have no beta-carotene Need to develop two technologies: Clone genes for beta-carotene Protocols for transforming rice 1991: First gene needed for beta-carotene cloned (Chamovitz D.A. et al., 1991) 1994: First rice transformation 2000: Three needed genes engineered into the first golden rice 2007: Next generation rice strains have nine introduced genes to increase vitamin A and protein content.

24 Next generation nutritionally enhanced plants Grains with full protein Hypoallergenic rice (or peanuts)

25 Protection from Insects

26 Cotton, Bugs and BT Toxin, Boll weevil and other insects can completely destroy cotton crops The bacteria Bacillus thuringiensis (BT) kills insects due to a toxin that punches holes in cell membranes. The BT toxin only works in an alkaline environment (like in insect guts), so is safe for humans. Organic farmers spray entire fields with X the bacteria (and anything else it might do). Through genetic engineering, the BT toxin has been put into cotton, so the cotton is naturally resistant to insects.

27 Protection from Insects

28 Protection from Insects Is this good? The accumulative reduction in pesticides for the decade 1996 to 2005 was estimated at 224,300,000,000 tons of active ingredient. Less poisons in our soil Less poisons in ground water Savings in petroleum used to make pesticides

29 Inhibition of fruit ripening Normal ripe fruit (A) Same fruit as (B), sprayed with ethylene No ethylene (fruit ripening hormone) by genetic engineering (B)

30 Producing naturally decaffeinated coffee plants Ogita et al.(2003) Nature, 423: 823

31 Herbicide resistance

32 Long-lived carnation

33 Problem 4: 3 rd world disease Barriers to immunizations: Cost Lack of refrigeration Social acceptance of shots

34 Solution: Oral Immunization

35 Problem 5: Petro-chemicals (plastics, gasoline, pesticides)

36 Petro-chemicals (plastics, gasoline)

37 Biodegradable (plant made) plastic

38 Modified Oils

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41 (Psychological) Barriers to Genetically Modified Food 1. Its not natural! 2. Its dangerous! In the U.S., children die annually because of allergy to peanut butter. In the U.S., there has been 1 documented case of death due to allergy to transgenic corn

42 Actual scene from a pro-organic documentary

43 What s really dangerous? In China, in 2000, 29% of farmers who DID NOT use transgenic cotton suffered from pesticide poisoning, while only 7% of those who did use transgenic cotton got poisoned. As an added bonus, yield of the transgenic crops was up 50% per hactacre, and revenue up 400% per hactacre.

44 Agriculture must be sustainable

45 Contribution of Biotech Crops to Food Security, Sustainability and Climate Change From 1996 to 2013: Increased crop production valued at US$116.9 billion Reduction of 497 million kg of pesticides Reducing CO 2 emissions by 26.7 billion kg / year Potentially conserving biodiversity by saving 123 million hectares of land Help alleviate poverty

46 (Psychological) Barriers to Genetically Modified Food 1. Its not natural! 2. Its dangerous! 3. Monsanto owns all the patents

47 What are the challenges for this century (aside from world peace )? Find a way of reducing population growth Find a way of feeding the increased population Increased yield on dwindling land Reduce our dependency on fossil fuels Reduce green house emissions Reduce pollution Increased use of recyclable materials Maintain a supply of pure fresh water, free of chemical contaminants Cure cancer