Genetically Modified Crops

lessfrustratedΒιοτεχνολογία

23 Οκτ 2013 (πριν από 4 χρόνια και 2 μήνες)

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Genetic modification involves the insertion or
deletion of genes.
It is a special set of
technologies that alter the genetic makeup of
organisms Combining genes from different
organisms, the resulting organism is genetically
modified


The
method to introduce new genes into plants
requires several important factors such as specific
promoter, codon usage of the gene and how to
deactivate the gene. The specific promoter must
relate to area that we want the gene to express.
The transgenic genes should also be able to be
denatured by heat in order for human
consumption








Two physical barriers prevent the entry of DNA
into the nucleus, the cell wall and plasma
membrane


Delivering the DNA into the cell


Agrobacterium
-
mediated transformation delivers
the DNA specifically into the nuclear compartment
with high efficiency and also provides a
mechanism for its
integration


Protoplast
-
mediated transformation, the cell wall is
digested with a mixture of
enzymes


Biolistic transformation uses fine metal particles
coated with DNA that are accelerated with
helium


Microinjection uses silicon carbide fiber treatment,
vacuum infiltration, dipping of floral parts,
sonication, and electroporation, cause transient
micro wounds
in the cell wall that allows DNA in
the medium to enter the cytoplasm


Microinjection

Protoplast


C
rops



Enhanced taste and quality


Reduced maturation time


Increased
nutrients in GM crops


Higher yields


Higher stress
tolerance


Improved resistance to disease, pests, and
herbicides


New products and growing techniques


Drought tolerance


Society



Increased
food security for growing
populations


Lower cost of food


Increase in the amount of successful crops
that yield more money


Help stomp out famine





Safety


Potential human health impacts, including allergens, transfer of
antibiotic resistance markers, unknown effects


Potential environmental impacts, including: unintended transfer of
transgenes through cross
-
pollination, unknown effects on other
organisms (e.g., soil microbes), and loss of flora and fauna
biodiversity


Domination
of world food production by a few companies


Increasing dependence on industrialized nations by developing
countries


Biopiracy, or foreign exploitation of natural resources


Ethics



Violation of natural organisms' intrinsic values


Tampering with nature by mixing genes among species


Objections to consuming animal genes in plants and vice versa


Labeling Not
mandatory in some countries (e.g., United States)


Society


Introducing
allergens and toxins to food


Antibiotic
resistance


Adversely changing the nutrient content of a crop


Creation of "super" weeds and other environmental risks


Example
-

found soybeans expressing a storage protein from Brazil


nuts
that showed allergenic properties can be transferred.




Pictures
from (
Science

Creative

Quarterly
)
http://microbewiki.kenyon.edu/index.php/Agrobacterium
http://seedmagazine.com/page/about/


D.Z
. Skinner and G.H. Liang.

Genetically Modified Crops Their
Development, Uses, And Risks.
Food Products Press. 2004. as well as




Pros
http
://
www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml


Pictures from: http://www.escience.ws/b572/L20/L20.htm,
http://www.sonidel.com/sonidel/ltm
-
1000
-
laser
-
thermal
-
microinjector/,


http://www.webmd.com/food
-
recipes/features/are
-
biotech
-
foods
-
safe
-
to
-
eat