Crop biotechnology and food production. Maarten J. Chrispeels.
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Transcript of Crop biotechnology and food production. Maarten J. Chrispeels.
1. Every person has sufficient food for a healthy life
2. Malnutrition is absent
3. Food comes from effective low-cost systems
4. Food production is compatible with sustainable use of natural resources.
5. Farmers and farm workers earn a decent living
What moral vision do we have for food and food production in our world?
Food and Agriculture Requirements for 2050
• Two times as much food as is produced now!• Foods that relieve specific deficiencies• Eliminate food insecurity for 800 million people
Achieving this goal will require:
• Increased productivity per hectare (2X)• Agriculture with less environmental impact• Crops less dependent on water
There are many inputs into agriculture, but plant breeding (genetics) accounts for 50 % of all crop
yield increases.
Wheat in Mexico
1950 1960 1970 19800
4
3
2
1
To
ns
per h
ectare
All plant traits are encoded by genes. A plant has 30,000-40,000 genes. Molecular biology makes it
possible to identify the genes that are associated with specific traits. Many genes encode enzymes that
catalyze specific biochemical reactions.
Dwarf rice lacks the enzyme Gibberellin 3ß hydroxylase that catalyzes the conversion of GA20 (inactive) to GA1 (active in elongation).
Dwarf, GreenRevolution riceon the left.
Domestication followed by plant breeding changed the genetic makeup of maize (corn) which was
derived from teosinte.
Corn Teosinte
QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
The March of Genetic Technology
1860 Mendel: making crosses, introducing genes
1920 Discovery of hybrid vigor
1950 Inducing mutations (radiation; chemicals)
1960 Tissue culture and embryo rescue
1980 Plant transformation and GM crops
2000 Genomics (study of all the genes)
Gregor Mendel
Lycopersiconesculentum
Lycopersiconperuvianum
Back-crossseries
Tomato Cultivar
Introducing a trait by repeated “backcrossing” to a cultivar
Genetic technology # 1
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Hybrid corn (maize) and rice, the result of controlled crossing of two varieties, are raising crop productivity all over the world
Genetic technology # 2: Hybridization
When crossing two different species, the progeny (children) usually do not survive.
Or, if they survive, they are not fertile (mule). Culturing the early embryo that
results from the cross under special conditions in the laboratory, can result in fertile plants that have the best properties
of both species.Ex.: cross of Asian and African rice
Asian rice
African rice
Mule: Horse X Burro
Genetic technology # 3Interspecific crosses andembryo rescue
Aerial view of Gamma Field for radiation breeding in Japan
Hundreds of crop varieties have been produced by irradiating plants or seeds
followed by breeding.
Genetic technology # 4:Radiation breeding
Genetic technology # 5: Plant transformation to introduce a gene (GM technology/genetic engineering or GMOs)
Creation of a GM plant relies on a natural gene transfer mechanism
QuickTime™ and aPhoto - JPEG decompressor
are needed to see this picture.
Bacillus thuringiensis produces an insecticidal protein. When the gene that encodes this protein is introduced in cotton and
other crops, the crops are resistant to certain insect pests.
Example # 1: Insect resistant cotton, a successful GM crop
Why do cotton farmers all over the world love GM cotton that is insect resistant?
It cuts insecticide application by 40 %, saves money and increases yields.
Example # 2: Herbicide (Roundup) resistant GM soybeans have been rapidly adopted by farmers
world-wide because they simplify weed management and save money.
They also facilitate no-till practices reducing the environmental impact of agriculture.
GM technology can be used to increase the vitamin content of foods
Vitamin A-rich rice (“Golden rice”) is the first example.
Greenpeace calculations show that an adult would have to eat at least 3.7 kilos of dry weight rice, i.e. around 9 kilos of cooked rice, to satisfy
his/her daily need of vitamin A from "Golden Rice". In other words, a normal daily intake of 300 gram of rice would, at best, provide 8%
percent of the vitamin A needed daily. A breast-feeding woman would have to eat at least 6.3
kilos in dry weight, converting to nearly 18 kilos of cooked rice per day.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.The Dilemma
The recommended daily allowance for Vitamin A is 700 g per day for females and 900 g per day for males. Your intake of carotene needs to be 10 x as much because of inefficient conversion.
Lines used for subsequent calculation.
SGR 1 SGR2Wildtype
SGR2: 16g developed by private sector; donated to the humanitarian
project
SGR1: 1.6g regulatory
clean; jointly developed by
public & private sector.
How much rice does a child need to eat to prevent VADD?
50% RDA sufficient to prevent vitamin A malnutrition!
How much rice does a child need to eat to prevent VADD?
Estimation from International Food Policy Institute:
(2) Vitamin A contribution from food intake.
Conversion factor used: 12:1
RDA
VADD without Golden Rice!
No VADD with Golden Rice!
Isoflavone *
Anthocyanins
Isoflavonoid/Flavonoid biosynthetic pathway to produce
antioxidants.
Naringenin can be converted to isoflavone by IFS (isoflavone synthase) and
dihydrokaempferol can be converted to anthocyanin pigments or to quercetin.
Quercetin
*
Genetically engineered plants (GMOs) for industry
Aspen, genetically engineered to have less lignin, grow faster and have a lignin to cellulose ratio of 1:4 instead of 1:2. Lignin removal in the paper industry is expensive and highly polluting.
Two plant genomes have been fully sequenced. The genomes of pathogens have been sequenced.This information is being used to discover the functions of important genes.
Genetic technology # 6: Genome sequencing and gene discovery
Gene knowledge from one plantis immediately transferable to othersplant species. Our understanding increases exponentially.
Genetic crop improvement will require use of all plant bio-technologies
Current array: 26,912 oligonucleotides(26,090 Arabidopsis genes, 822 controls)
ag vs. L- er
Tissue culture
GM Technology
Genomics
What about the consumer?What about the farmer?
What about the environment?
El consumador? El campesino? El ambiente?
GM crops are highly regulated and as safe as other crops for
the consumer!
• Government regulations have made it quite difficult to introduce GM crops. In the USA they have to be approved by the USDA, the EPA and the FDA. Each country has its own agencies.
• All new crops are tested and approved on a gene by gene and crop by crop basis.
• The tests are expensive and companies will only develop those crops for which there is a clear financial reward and return on investment.
Is “organic” better?• Consumers can switch to “organic” where GM
is not allowed, but there is little scientific evidence that organic crops are more nutritious or healthier than traditional crops.
• Nutritional value depends on ingredients, not on the method of plant breeding.
“Junk food” can be made from “organic”crops as long as the crops are grownaccording to the organic rules. “Organic”is no guarantee for quality.
Not all products carry warning labels.
Margarine contain trans-fatty acids producedduring the hydrogenation of vegetable oil. There is considerable evidence that TFAs area contributing factor to cardiovascular disease.To label or not to label is as much a politicaldecision as a scientific one. Remember theLong struggle to get warning labels oncigarettes?
9% TFA
14% TFA
26 % TFATFA = trans-fatty acids
Voluntary labeling works in the US for Kosher and Organic foods. Europe requires that all food that has any ingredient that is
more than 0.9% GM be labeled as “GM containing”.
What about the environment?
“No-Till” crop planting, which avoids plowing the soil, conserves
water, reduces dust and saves energy. It is made easier with herbicide resistant soybeans.Harvesting soybeans in the Cerrado
No-till soybeans in the USA
Iguazu will always be there, but we can’t be sure about the rainforests. Most wilderness
will disappear unless we can raise agricultural productivity by 100% (2-fold)
Benefits of GM crops to the farmers
Lower production costs (fewer pesticide applications in Bt crops)
Healthier work environment (fewer pesticides)
Less work (easier weed control with GM soybeans)
Greater yields and more income.
Four crops account for 99.5 % of all GMOs
Biotech Crops - Planted by 7 million Farmers in 18 countries in 2003
Biotech Crops - Planted by 7 million Farmers in 18 countries in 2003
canola
cotton
corn
soy
Million Acres
0
20
40
60
80
100
120
140
160
180
1996
1997
1998
1999
2000
2001
2002
2003
2004
200
Forec
ast
Forec
ast
Benefits for developing countries: consumers, farmers and the environment.
1. 15 % of the population is still food insecure2. Big farmers can benefit as in developed countries3. Small farmers can benefit (examples already in China, Philippines,South Africa etc)4. To preserve the environment we need to raise productivity 2-fold (population increase).
European opposition to GM crops
Europeans are well-fed and agriculture is heavily subsidized.No need to support this “American” technology.Farmers can do well without this technology.Anti-globalization forces have made GM crops their line in the sand.
The US has taken a conservative approach.
Europe has taken a very conservative(precautionary) approach.
What should other countries do?
Genetic modification with molecular methods is an important new tool in the toolbox of the
plant breeder.Better seeds (genetically improved) are the
most important input into agriculture.There is no reason not to accept foods from
GM crops and every reason to embrace them.
This does not mean that GM technology by itself will feed the hungry or that agricultural practices cannot be improved.