Transcript Biotechnologies Influencing Agriculture: Molecular

Biotechnologies Influencing
Agriculture:
Molecular Pharming
Betty Ikawati, Rahmi Yuniarti, Nita
Plant made Pharmaceutical Wave of Agricultural
Biotechnology
First Generation : Agronomic traits
Second Generation : Nutritional
Enhancement traits
Third Generation : Plants/animals as
Factories
Molecular Pharming by
Chloroplast Transformation

Chloroplast transformation for transgene
containment
Chloroplasts : - class of plastids
- organelle
- from cyanobacteria (blue-green
bacteria )
- contain chlorophyll
transformation of the chloroplast
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1988 : - putting the foreign genes into chloroplast
genome
Late 1990 : several biotech companies have initiated
major programmes on chloroplast transformation
1998 : Chloroplast transformation has been touted
at least as far back as 1998 as a means
of “containing” transgenes; that is, preventing them
from transferring to non-GM crops or wild relatives
through pollen, and hence preventing the creation of
transgenic herbicide tolerant weeds. The theory is
that chloroplasts are inherited exclusively through
the female line.
Other benefits of
chloroplast transformation
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Chloroplast transformation involves homologous
recombination
In practice, the inserted transgene has short
DNA sequence tails added at each end, the tails
are homologous to sequences on the chloroplast
target gene, which thus initiate homologous
recombination. Once the transgene is inserted
into the chloroplast chromosome, the target
gene is disrupted. The disruption of the target
gene is expected to alter the growth and
metabolism of the plant
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Leaf discs are bombarded with plasmid constructs
containing a selectable antibiotic resistance marker
physically linked to the gene of interest, flanked by
DNA for inserting into the correct site of the
chloroplast genome. The antibiotic resistance marker
most frequently used is the aadA gene encoding
resistance for spectinomycin and streptomycin,
driven by the promoter of the chloroplast encoded
16S rRNA gene.
this transformation procedure applied to tobacco,
Arabidopsis or oil seed rape, generates plants in
which all the chloroplast genomes are uniformly
transformed
(a
condition
referred
to
as
homoplasmic), despite the fact that tobacco leaf
cells may contain 100 chloroplasts, each containing
100 copies of the chloroplast genome.

Transformation of the chloroplast genome by
bombarding tobacco leaves with microprojectiles
coated with DNA. Following bombardment, leaf
discs are placed onto antibiotic-containing
medium (panel A). Transgenic plants are
regenerated from the transformed tissue that is
able to develop green chloroplasts (panel B)

Another advantage of chloroplast transformation
is that foreign genes can be over-expressed,
due to the high gene copy number, up to 100
000 compared with single-copy nuclear genes.
And there does not seem to be gene-silencing
and other instability that plague nuclear
transformation. The gene product is retained
inside the chloroplasts or can in principle be
targeted to a specific compartment in the
chloroplast.
Plant Made pharmaceuticals

The manufacturing of bulk active
pharmaceutical ingredients derived from
plants
• A transgenic plant/seed is developed to
perform as a high production system
• The plant/seed containing the active
pharmaceutical ingredient is harvested
• The active pharmaceutical ingredient is
isolated and processed to be used in
pharmaceuticals