Historical background
The first GMO was obtained in
1973 by Stanley Cohen and Herbert Boyer. In 1974,
the scientific community imposed itself an international suspension
of the use of recombinant DNA technology, as a precautionary
measure in order to have time to evaluate the new
technology’s progress and the possible risks. The conference
collecting the achieved results was held in Asilomar in California.
It concluded that experiments on recombinant DNA could proceed as
long as they respected strict guidelines, which were prepared by
the National Institute of Health and accepted by the
scientific community. These guidelines are still used to inspire
gene transformation research and experiments. The same strictiness
was also applied to regulations on the commercial use and
environmental release of these organisms. The aim was to only allow
the use of varieties and animals that were considered safe for the
environment and for human and animal consumption.
The first transgenic animals were mice. They were
created in 1974 by Rudolf Jaenisch, who completed the insertion of
an external gene inside embryos. Later, Jaenish showed the
actual efficiency of the transgenetic process. His mice not
only had integrated the external DNA but were also able to hand
this feature down to their descendants.
In the vegetable sector, the main progress in
the practical application of biotechnology has taken place over the
last twenty years. In particular, vegetable biotechnology started
when test-tube culture methods for vegetable cells and/or tissues
were combined with the recombinant DNA technology and with the
development of systems that insert single genes directly in the
cell nucleus.
Combining the possibility of regenerating whole plants from a few
cells, on one side, and the possibility of modifying the DNA
content and structure of single cells on the other, provided an
extraordinary tool for the production of genetically modified
plants.
There are five main methods to permanently introduce a specific
gene in a plant’s genome and to modify and adapt it to the
specific features of the single plant species. These are:
The Agrobacterium infection technique produced the first
transgenic plant in 1983. It created tobacco that was able to
resist an antibiotic.
In the early 1980s, some private companies were able to transfer a
copy of the Bacillus thuringiensis gene to plants, in
order to endow them with insect-resistant features. B.
thuringiensis is a bacteria commonly found in soil that
produces a protein which is toxic for most phytophagous insects but
harmless for human beings.
In 1994, the United States authorized the distribution of
the first transgenic plant products. This was the
Flavr Savr tomato, characterized by fruits that kept their
compactness even at an advanced ripeness.
In the last few years, various transgenic plants belonging to
different species have been obtained and their cultivation has been
authorized. In these plants, the insertion of genetic traits has
determined some specific features such as:
- herbicide tolerance (gliphosate, gluphosinate);
- insect resistance (Bt);
- male sterility;
- virus resistance;
- fungi resistance;
- environmental stress resistance (low temperatures, salinity,
etc.);
- biosynthetic alteration (contained in: nitrates, proteins, fat
acids, etc.);
- morphological amendment (ramification, bearing, etc.)
- increased productivity.
Genetic engineering is now addressing new sectors such as the
production of high added-value products derived from plants.
For the production of this new “biomaterial”, attention
is paid to direct improvement or to the amendment of the
plant’s constituents and to the production of non-vegetable
compounds in plants.
