Biotechnology and Crops
E. Souza
Professor, Plant Breeding and
Genetics
Basic Areas of Biotechnology
Research
Sequence and Function
Sequencing all the DNA of corn, rice, and
Arabidopsis
(a small mustard).
Comparable Human research: The Human
Genome Project
Sequence and function
TATAGTCCAUG
Gene sequence
Arabidopsis
TATAGTCCAUG
Gene sequence
Potato
Protein structure
and function
Model
proteins
Design DNA
probes
New understanding of plant
function and faster approaches
to crop improvement
Basic Areas of Biotechnology
Research
Structure and Function
Diagnostics
Identifying genes that cause disease resistance
or quality enhancement.
Human research: Identifying ‘cancer’ genes
Consensus map:
Triticeae Group 1
Chromosome.
Wheat
Rye
Barley
Rice
Maize
Source: Graingenes
Autoradiogram of
DNA marker from oat
CDO64
One of many gene
markers used to
construct maps of
cereals.
Source: Graingenes
Difficult traits such as head scab
resistance are easier to select by
selecting directly for DNA
rather than the disease
Marker Assisted
Selection
Smaller DNA
Large DNA
Basic Areas of Biotechnology
Research
Structure and Function
Diagnostics
Genetic Engineering of Crops
Defined by transfer of genetic material from one
organism to another through nonsexual means
Comparable human research: ‘Gene therapy’
treatments
Genetic Engineering of Crops
Isolation of gene
Development of new ‘construct’ or ‘vector’
A carrier often small circular or linear DNA
Other genes for efficient transfer
Regulatory genes to activate the target gene
Insertion into plant
Selection and recovery of plants with
activated gene
Regulation of Genetically Engineered Plants
GE plants for lab use
Regulated by internal biological safety
committees
Vast majority of engineering ‘events’
Field testing and transport – APHIS
Safety and use – EPA, FDA, or both
Marketing – All of the above plus other
nation’s regulatory agencies
Frequency of Journal Publications Listed
in AGRICOLA Database
1351
540
5236
466
0
1000
2000
3000
4000
5000
6000
Pu
blicati
ons
19921997
19992003
Transgenic Plants
Crop Cultivation
Traits Used for Enhancing Crops
Herbicide resistance
Roundup ready
Bialophos resistant
Bromoxinyl resistant
Bt organic insecticide
Different forms of
Cry
proteins from a pathogen
of insects
Virus resistance
coat protein genes
Potatoes in foreground are normal, background protected
from Roundup Herbicide by a modified enzyme from bacteria.
Potatoes with
Cry
proteins from
B. thuringensis
protected from
Colorado potato beetles
Genetically Enhanced Daws Wheat
Resistant to Wheat Streak Mosaic
Virus from ‘96’97 Field Test
Types of traits incorporated into
genetically enhanced crops, 2002
75
17
8
0.5
0
10
20
30
40
50
60
70
80
90
100
% o
f
GE crops
Herbicide
Tolerance
I nsect
Resistance
Herb &
I nsect
Resist.
Quality or
Virus
Source: C. James, 2002, ISAAA
United States
63%
Argentina
21%
Canada
6%
Brazil
4%
Other
1%
South Africa
1%
China
4%
Percent of land area planted to transgenic crops by country
2003 – total global land area planted: 167 million acres
http://www.
colostate
.
edu
/programs/
lifesciences
/
TransgenicCrops
/current.html#crops
Soybean
62%
Maize
21%
Cotton
12%
Canola
5%
Squash
0%
Papaya
0%
Relative percent of transgenic cultivars by crop, 2002
http://www.isaaa.org/kc/Publications/pdfs/isaaabriefs/Briefs%2027.pdf
Traits Used for GE Crops:
Crop Quality
Ripening gene modifications
Pharmaceuticals and Vaccines
Traits Used for GE Crops: Crop Quality
Ripening gene modifications
Pharmaceuticals and Vaccines
Vitamin A enhancement of rice
Additional gluten genes
Oil composition
Essential oils/flavors
GE Crops: Risks and Problems
Consumer acceptance
Safety/allergenicity (Perceived and actual)
Naturalness
GE Crops: Risks and Problems
Consumer acceptance
Poor Utilization
Traits are expensive – the cost of technology as
described in essay
Tendency to overuse
GE Crops: Risks and Problems
Consumer acceptance
Naturalness
Poor Utilization
Weediness
Weediness of crop
Escape of genes
GE Crops: Risks and Problems
Consumer acceptance
Naturalness
Poor Utilization
Weediness
Safety/Labeling
Segregation of products expensive
Labeling is cheap – the process to match the
food to the label is very expensive
So Why Do Genetic Engineering?
In some cases we will not
Roundup Ready Wheat Terminated in 2004
Reduce costs and lower agriculture’s
environmental impact
less pesticides
lower rate and toxicity
Traits available throughout third world
Competitive edge?
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