Biotechnology and Crops

E. SouzaProfessor, 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

TATAGTCCAUGGene sequence

Arabidopsis

TATAGTCCAUGGene sequence

Potato

Protein structureand function

Model proteins

Design DNAprobes

New understanding of plantfunction 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.WheatRyeBarleyRiceMaize

Source: Graingenes

Autoradiogram of DNA marker from oatCDO64

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 DNArather 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 non-sexual means

Comparable human research: ‘Gene therapy’

treatments

Genetic Engineering of CropsIsolation 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 – APHISSafety and use – EPA, FDA, or bothMarketing – 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

on

s

1992-1997 1999-2003

Transgenic PlantsCrop 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 Round-up Herbicide by a modified enzyme from bacteria.

Potatoes with Cry proteins from B. thuringensis protected fromColorado 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

178

0.50

102030405060708090

100%

of

GE

cro

ps

HerbicideTolerance

InsectResistance

Herb &InsectResist.

Quality orVirus

Source: C. James, 2002, ISAAA

United States63%

Argentina21%

Canada6%

Brazil4%

Other1%

South Africa1%

China4%

Percent of land area planted to transgenic crops by country 2003 – total global land area planted: 167 million acreshttp://www.colostate.edu/programs/lifesciences/TransgenicCrops/current.html#crops

Soybean62%

Maize21%

Cotton12%

Canola5%

Squash0%

Papaya0%

Relative percent of transgenic cultivars by crop, 2002http://www.isaaa.org/kc/Publications/pdfs/isaaabriefs/Briefs%2027.pdf

Traits Used for GE Crops: Crop Quality

Ripening gene modificationsPharmaceuticals and Vaccines

Traits Used for GE Crops: Crop Quality

Ripening gene modificationsPharmaceuticals and Vaccines Vitamin A enhancement of riceAdditional gluten genesOil compositionEssential oils/flavors

GE Crops: Risks and Problems

Consumer acceptance Safety/allergenicity (Perceived and

actual) Naturalness

GE Crops: Risks and Problems

Consumer acceptancePoor Utilization Traits are expensive – the cost of

technology as described in essay Tendency to overuse

GE Crops: Risks and Problems

Consumer acceptanceNaturalnessPoor UtilizationWeediness Weediness of crop Escape of genes

GE Crops: Risks and Problems

Consumer acceptanceNaturalnessPoor UtilizationWeedinessSafety/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?