1. Chapter 12: Transgenic crop plants
Inactivation of a gene (antisense)
Herbicide tolerance
Insect resistance
Other examples
Regulations

2. Modification of genetic characteristics
To produce an extra protein
e.g. Roundup ® Ready Soja
Bt rice
To stop the production of a specific protein: antisense strategy
e.g. Flavr Savr ® tomato
e.g. virus resistant plants

3. Flavr Savr ® tomato (Calgene)
Antisense polygalacturonase (cell wall - degrading enzyme) to prevent overripening of the fruit
(tomato gene in reverse orientation)
Zeneca tomato paste first on the market in US and also in UK in 1996.
Taken from the market in 1999 due to negative propaganda in the media.

4. Antisense strategy messenger RNA ANTISENSE protein coding sequence
promoter
promoter
DNA
messenger RNA
ANTISENSE
protein
Not only useful for functional analysis, also for applications

5. Longer fresh
Tomatoes with less cell wall degration are stronger and less susceptible to fungal infection.

6. Anti-overripening (also with other genes)
Other examples in the pipeline:
squash, melon, strawberry, banana, papaya, etc.

7. HT Herbicide tolerant soya or corn or rice
Tolerance to herbicides that are specific for plants and thus less toxic to animals e.g. glyphosate (Roundup®) or gluphosinate (Basta® of Liberty®)

8. HT Roundup ® ready soya (Monsanto) Glyphosate-tolerant soya
The herbicide glyphosate blocks EPSP synthase, an enzyme for biosynthesis of aromatic amino acids
EPSP synthase of Agrobacterium CP4 is relatively insensitive for glyphosate
Monsanto’s transgenic soybean contains :
P35S - TP EPSPS Petunia - EPSPS (CP4) - 3’nos
Promoter - localisation - GENE – terminator
signal for protein
This soybean stays as (in)sensitive to other herbicides as non-transgenic soybean, the only change is its tolerance to glyphosate by the intorduction of one gene

9. HT
Plants protected
Herbicide tolerant soya, corn and oilseed rape are commercially cultivated in the US and Canada

10. HT Soya with Soya without Herbicide treatment herbicide treatment
` Bron: Monsanto

11. Herbicide tolerant soybean in the worldHT
US: soya 2 HT % in 1996; 77 % in 2002 (>20 milj ha)
Global: 60% of the
90 M ha in 2005
Argentina:
95% of the 9,6 milj ha in 2000 = HT

12. HT Why use it? The farmer Less costs simpler The environment
Much less toxic for animals
10-40% less herbicide needed
biodegradable

13. HT
Concerns
Dependence on chemical herbicides stays in this way of farming
“superweeds”
Uncareful use can lead to resistance in weeds (this can also happen in the trasditional use of these herbicides or with other herbicides)

14. HT Herbicide tolerant crops for developing countries?
Striga (parasitic plant) on corn  burn the field?

15. HT Left: control corn (striga damage)
Right: herbicide tolerant corn, seed treated with herbicide before planting, no striga damage

16. Insect tolerant crops by using Bt
Bt protein crystal toxic for insect larvae
Bacillus thuringiensis protein
Biological crop protection product
Environmentally friendly
Toxic for specific group of insects, for example only for beetles or only for caterpillars
Transgenic plant produces Bt-protein

17. Bt-corn BT
Bt control
Control Bt
Bt control

18. BT
Bt-cotton: biggest Bt success: on average 1.2 million kg less insecticide on cotton in US

19. BT
Bt-cotton in China
Study on website of isaaa:
Cotton of Monsanto or CAAS (China Academy of Agricultural Sciences)
Grown by 3 million small farmers in 2000 (ca. 10%)
On average 20-23% lower costs with Bt-katoen
ton less insecticide (- 47kg/ha)
Less farmer intoxications with Bt-cotton:
(4.7% compared to non-Bt: 22%)

20. BT Why use it? The farmer Lower costs for the farmer Higher yields
Less work: no of few spraying needed
For the environment
No or low use of insecticides
Much more target specific than insecticides

21. BT Concerns Bt crops may affect some useful insects
but less than with traditional insecticides
Large scale cultivation of Bt-crops can enhance the emergence of resistant insects

22. www.isaaa.org Worldwide total GM crops 1 million ha in 1996
Europe: only some crops are allowed (mainly corn)

23. Transgenic crops in the field: 90 mil. ha in 2005
Most important production areas

24. Transgenic crops in the field: 90 mil. ha in 2005
The traits in the transgenic plants in the field: mainly HT and BT

25. local crops or cultivars relevant characteristics
Transgenic crops for developing countries
local crops or cultivars
relevant characteristics
preferentially own technology
own production
for example Cornell University developed
Virus resistant papaya for Hawaï/Philippines

26. Transgenic crops for developing countries
Besides Bt cotton, China has also developed its own transgenic herbicide tolerant rice and insect tolerant rice.
Kenya is developing its own herbicide tolerant and insect tolerant corn.
Mexico has developed aluminium-tolerant corn
Virus-resistant cassava has been developed
Fungus-resistant banana for Ecuador/Uganda (Kuleuven)
Nematode resistant potato for Bolivia (University Leeds)

27. Production of sugar trehalose at drought stress
Transgenic crops for developing countries
Drought tolerant rice
Production of sugar trehalose at drought stress
Mechanism cfr. other drought- tolerant plants
BBC nieuws 26-11
PNAS vol.99 p (2002)
GM control

28. Transgenic crops
Transgenic crops can only be grown after a permission has been given. A technical dossier with all the details of the characteristics of the transgenic plant and the results of toxicity test and environmental risk analysis has to be given to the authorities.
In Europe the regulations are very demanding and foods containing ingredients from transgenic crops have to be labeled. In the US this is only required if the transgenic crop has a different composition than the non-transgenic crop (e.g. a different oil composition).
list of commercially grown GMOs in USA
list commercially grown GMOs in Europe

29. GMO’s in the media: many false messages
GMO’s are allergenic
GMO’s make you impotent, make your brain shrink
Bt corn kills the Monarch butterfly
Genes from GMO’s spread without control, normal genes don’t
Many of the other claims are true but also hold for traditionally bred varieties, for example risks of herbicide tolerant plants

30. Transgenic soya Non-transgenic soya
Herbicide tolerant
gene can “flow”
biodegradable
Roundup, low toxicity
tested in detail before
commercialisation
modification known
Monsanto
Herbicide tolerant
gen can “flow”
persistent Synchrony
low toxicity
no procedure
for commercialisation
modification unknown
Dupont
Both varieties are sold by
© 1999 Pioneer Hi-Bred International, Inc.
Archer Daniels Midland offers now more money for the non-GMO!!!

31. Conclusion :
It is wise to be careful with transgenic plants, to test them before putting them on the market, but this testing is thoroughly done.
Possible risks of transgenic plants have to be compared with risks also occurring with traditionally bred varieties and conventional field practices.