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Professor Jerry RobertsSchool of Biosciences
Global Food Security – is there a Role for the Genetic Manipulation of Crop
Plants?
• Food demand will rise by approximately 50% by 2030
• Global population to approach 9 billion
• Increased consumption of meat, fish and dairy products
United Nations forecasts:
Global Food Security
Global Food Security
A household is considered ‘food secure’ when its occupants do not
live in hunger or fear of starvation
Global Food Security
World-wide around 1 billion people are hungry due to
extreme poverty, while up to 2 billion lack food security
intermittently
Global Food Security
World-wide around 1 billion men, women and children are obese, while up to 2 billion
adults are described as overweight
The challenge
Global Food Security
To increase food production with the same amount of land, but:
• Using less fertilisers• Using less water• Using less energy• Sustainably
Not forgetting climate change
Global Food Security
Is there a role for GM technology to engineer crops
that use resources more efficiently and are more
sustainable?
History of GM• 1953 Structure of DNA
• 1964 Green revolution
• 1972 Recombinant DNA
• 1973 Insertion of foreign DNA
• 1975 Ground rules on GMOs in Labs
History of GM
• 1983 Tobacco plant expressing luciferase
• 1994 Flavr savr tomato
Isolate gene of interest
Insert into a bacterium
Transform plants
Confirm plant properties
Tomato plant tolerant of low temperature
Use of GM technology to improve crops
Crop improvements using GM technology
Resistance by inserting a single transgene
• Herbicides• Insects• Viruses
Herbicide-resistant tomato plants
Transgenic Wild type
Crop improvements using GM technology
Weed-infested non-transgenic soybean plot
Herbicide resistant soybeans after Roundup
treatment
Herbicide resistance in the field
Crop improvements using GM technology
Insect resistant tobacco plants
Transgenic Wild type
Crop improvements using GM technology
Corn hybrid with a Bt gene (left) and a hybrid susceptible to European corn borer (right)
Stem undamaged
Stem damaged
Crop improvements using GM technology
Quality traits
• Increased shelf life• Improved flavour• Designer oils• Nutritional value
Crop improvements using GM technology
Post harvest losses of fresh fruits and vegetables
From 20-50% of the total crop may be lostDeterioration and wastage leads
to:• Decrease in quality• Reduced nutritional value• Lower income• Fewer jobs• Hungry people
Down regulation of a biochemical pathway
A B C D
A B C
A B
A
Crop improvements using GM technology
DUPLEX FORMATION
Protein synthesis blocked
Sense mRNA
TRANSCRIPTION
Antisense mRNA
Sense gene
Protein synthesis
TOBACCO FLOWERS
SENSE ANTISENSE
Use of antisense RNA technology
Antisense gene
blocked
Fruit ripening can be arrested in tomato fruit
Sodium thiosulphate treatment
Silver thiosulphate treatment
Use of antisense RNA technology
Regulation of Fruit Ripening
ETHYLENE
ACTIVATE A CASCADE OF GENES
CO-ORDINATE BIOCHEMICAL CHANGES
FRUIT QUALITY
COLOURFLAVOUR& AROMA
TEXTURE
GR R
Proteins
Green fruit Ripe fruit
Degraded
PG
Softening is caused by the activity of the pectin-degrading enzyme polygalacturonase (PG)
Intact
Cell wall
Regulation of Fruit Ripening
1 2 3 4 5 6
Antisense lines
Inhibition of PG accumulation by antisense transgenes
0
25
50
75
100
GR R 1 2 3 4 5 6
PG a
ctiv
ity
(%)
GR R wt Antisense lines
GR R wt
Use of antisense RNA technology
Antisense PGControl
Inhibiting PG synthesis with an Antisense Gene reduces fruit deterioration and spoilage
Use of antisense RNA technology
Tomato puree made from antisense PG fruit on sale in the UK from 1996
Use of antisense RNA technology
Synthesis of Ethylene – The Hormone involved in Ripening and Senescence
SAM(S-adenosylMethionine)
ENZYMIC STEPSCATALYSED BY
ACC1-amino cyclopropane
1-carboxylic acidEthylene(ethene)
ACC Synthase ACC Oxidase
Synthesis of Ethylene
Synthesis of Ethylene – The Hormone involved in Ripening and Senescence
SAM(S-adenosylMethionine)
ENZYMIC STEPSCATALYSED BY
ACC1-amino cyclopropane
1-carboxylic acid
ACC Synthase ACC Oxidase
Reduced Ethylene
Use of antisense technology to regulate ethylene synthesis
Control
Blocking ACC oxidase synthesis prevents fruit spoilage
Use of antisense RNA technology
Antisense ACC oxidase
Antisense ACOControl
Antisense ACC oxidase tomato plants exhibit delayed leaf senescence
Use of antisense RNA technology
Novel products:
• Vaccines• Antibodies• Pharmaceuticals• Biodegradable
plastics
Crop improvements using GM technology
Generation of golden rice
• Rice is a major world crop• It contains no Provitamin A• 400 million people suffer
from vitamin A deficiency • Many babies go blind• Conventional breeding not
effective
………..so why are so many people opposed to GM crops?
GM crops and Global Food Security
Bad publicity
GM crops and Global Food Security
GM crops and Global Food Security
Opposition by ‘pressure’ groups
So what are the concerns?
GM crops and Global Food Security
• Impact on the environment• Safety of products• Interfering with nature • Irreversibility• Exploitation of farmers in
developing countries
GM crops and Global Food Security
Conclusions • Urgent need to address the issue of GFS• Need to improve the resource efficiency and
sustainability of agricultural production • GM technology provides a useful strategy to
help us achieve these goals• Need a dialogue between scientists,
environmental pressure groups, and the public to resolve issues surrounding growing and utilisation of GM crops
