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A case study: Cisgenic barley and
wheat for animal feed
Preben Bach Holm
Aarhus University
Science and Technology
Dept. of Molecular Biology and Genetics
Research Centre Flakkebjerg
DK-4200 Slagelse
Cisgenesis:
What are its implications for food safety, society
and economy
European Parliament ASP 5G-2, June 21, 2011
Project
Cisgenic barley and wheat for animal feed
Aim:
1) To develop new generations of genetically modified feed
barley and wheat based on the concept of cisgenesis
2) To assess if such crops provide environmental benefits,
have economic advantages and are perceived as useful and
ethical acceptable by the Danish citizens.
3) To achieve these objectives a research consortium has
been assembled that integrates expertise in plant molecular
biology, physiology, breeding, downstream handling and
processing, economy, sociology and ethics.
Cisgenesis criteria
1) Only utilize genes for genetic modification (genomic clones)
from the same species and species with which it can
intercross
2) The genetically modified plants should
•
have inserted the cisgene in the host genome with a
minimum of rearrangements and outside endogenous
genes
•
have no foreign DNA in the form of vector backbone
•
have no foreign DNA in the form of selection genes
Improvement of:
• Phosphate availability
• Amino acid composition
• Cell wall digestibility
• Starch digestibility
• Mineral bioavailability
Reduced N and P load
on the environment
Phytic acid and phytases
O Zn
O
++
H
Ca
O
O P O
O
5
++
H
P O
O
4
3
O
O Fe
O
H
P O
O
O
HO P O
O
O P O
Mg
++
O
H
2
H
6
O
O P O
O
1
H
++
Ca
++
• 70-80% of the phosphate
reserves in seeds are bound
as phytic acid.
• Phytic acid can only be
degraded by specific enzymes – phytases.
• Phytases are activated at
germination to ensure the
supply of phosphate to the
developing plantlet.
• Phytic acid inhibits the
uptake of zinc, calcium and
iron
Phosphate: An important nutrient and limited resource
• Monogastric animals like pigs, chicken and human cannot degrade
phytic acid since they lack phytase. In consequence most of the
phosphate is excreted and cause pollution
• Microbial produced phytase is today added to animal feed in areas with
intensive livestock production
• GM cereals that produce additional phytase may be a valuable
supplement to increase phytate digestibility
• Many livestock farmers mix their own feed from homegrown cereals.
• Organic farmers are not permitted to use microbial phytase
• Phosphate is a limited non-renewable ressource that is depleted in a
few decades
The PAPhy_a gene
Promoter
Gene
2730 bp
2388 bp
Exon
Terminator
734 bp
Intron
Co-transformation with Agrobacterium
LB
RB
Hygromycin resistance gene
p-Soup
Antibiotic resistance gene
LB x 2
PaPhy_a
p- Clean
Antibiotic resistance gene
RB
Frequency of cisgenic lines
Frequence of cisgenic lines= Frequency of GM lines * Frequency
of lines without backbone * Frequency of lines without hygromycin resistance gene *
Frecuency of lines with minimal rearrangement = 10%
Dosis effect of PAPhy_a
Public perception and ethical issues
The main results of the analyses were that cisgenic crops are acceptable
for a larger part of the population than transgenic crops. Hence, 56% of
the interviewed were willing to buy bread made of flour from cisgenic
wheat while only 19% were willing to buy bread made from transgenic
wheat.
The analyses further revealed that cigenic crops are considered to be
less unnatural than transgenic crops. The results are not unequivocal
though since the population operated with up to five different
understandings of unnaturalness and for some of these understandings
cisgenis is not necessarily considered to be more natural.
Perceptions of risks, benefits and unnaturalness remain, however,
relevant indicators of acceptance also for cisgenic crops. This implies
that the cisgenesis concept does not attend to all the concerns people
have about GM crops being unnatural and risky.
Miele, Lassen and Sandøe 2011. In preparation
Down-stream handling and segregation
On the farm
Storage facility on farm
Non cisgenic field
Animal
production
Cisgenic
field
Grain elevator
Slurry /
manure
Field on neighbour farm
Outside the farm
Haastrup, Nielsen, Hauge Madsen and Gylling 2011, in preparation
Consequences of different levels of regulation
for fodder wheat and barley
1. Cisgenic grain is handled as a Gmo (full regulation)
2. Cigenic grain has a lower level of risk assessment and
segregation requirements (deregulated)
3. Cisgenic grain is handled as a non-GM fodder grain
variety (No regulation)
1.
2.
3.
4.
5.
Cleaning harvester, grain wagon, seeder and baler
Cleaning grain transporter and storage containers at farm
Cleaning production line at grain elevator
Cleaning concrete floor
Annual cleaning
Break even analysis
Estimated potential price reduction on premix
per 1 ton of feed mix:
Scenario 1: 7,80 kr./ton
Scenario 2: 20,10 kr./ton
Scenario 3: 32,30 kr./ton
(- phytase)
(- phytase – 50% MCP)
(- phytase - MCP)
1) Substitution of phytase in on farm feed mix is economic
competitive (after coexistence costs) if cisgenic wheat is
used as the only grain component.
1) If all MCP or part of it can be substituted in the on farm
feed mix by cisgenic grain with high phytase activity both
cisgenic barley and wheat will be economic competitive
(after coexistence costs)
Gylling et al. 2011. In preparation
Wheat
Triticale
Trithordeum
CISGENIC GROUP
Rye
Barley
Rye x wheat x
barley
Gene pool concept in crop breeding
Primary gene pool (GP-1): Varieties of the
same species that can intermate freely
Secondary gene pool (GP-2): Closely
related species that can intercross with GP-1
and produce at least some fertile hybrids
Tertiary gene pool (GP-3): Distantly related
species that can intercross with GP-1 and -2
but requires additional measures such as
embryo rescue or chromosome doubling to
obtain offspring.
After: JR Harland and JMT de Wet. 1971. Toward a Rational Classification of
Cultivated Plants. Taxon 20: 509-517. and Wikipedia
Thank you for
your attention
Cisgenic barley and wheat for animal feed
A project funded by the Danish Directorate for Food, Fisheries and
Agro-business (Fødevareforskningsprogrammet 2006) and Plant
Biotech Denmark
Participating institutions:
COPENHAGEN UNIVERSITY
• Faculty of Life Sciences, Dept of Agricultural Sciences (Jan
Schjørring)
• Faculty of Life Sciences, Institute of Food and Resource Economics
(Peter Sandøe and Morten Gylling)
• Jesper Lassen, Faculty of Life Sciences, Department of Human
Nutrition (Jesper Lassen)
DANISH AGRICULTURAL ADVISORY CENTRE, THE NATIONAL
CENTRE (Kathrine Hauge Madsen)
SEJET PLANT BREEDING (Kurt Hjortsholm and Lars Eriksen)
UNIVERSITY OF AARHUS, Faculty of Agricultural Sciences, Dept. of
Genetics and Biotechnology (Preben Bach Holm)
Transformation in Wheat
Promoter
Genomic Ferritin clone
1DX5 Glutenin
Nos
1 kb.
Exon Intron
A
We have introduced extra copies of
the genomic sequence of the most
active homoeoallele of the TaFer1
gene into wheat by transformation
using the high molecular weight
glutenine1Dx5 promoter for driving
endosperm specific expression.
B
Biolistic transformed ferritin transgenic plants,
(A) on selection media and (B) in pots.