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[SANET-MG] scorpion toxin in canola
It will be claimed that no toxin will get into the canola oil. However,
the press cake is used for both feed and food (it added to junk
food).Will scorpion toxin injure us? If not in the toxin at least in the
Scorpion gene gives plants a sting in their tail
Oilseed rape: the modified plants have scorpion and moth genes
1 August 2005
Chinese scientists have inserted scorpion and moth genes into oilseed
rape (canola) plants to make them poisonous to insects feeding on them.
The researchers say that using two foreign genes at the same time means
insect pests will be less likely to develop resistance to the
genetically modified (GM) plants. The findings were published online in
Plant Cell Report on 19 July.
The researchers tested the GM plants by exposing them to caterpillars of
the diamondback moth (Plutella maculipenis). All of the plants showed
some defense against the caterpillars, although the extent of this
varied from plant to plant.
The caterpillars, which are major crop pests in parts of Africa, Asia
and Latin America, have developed resistance to several available
pesticides. There are also reports they are becoming resistant to 'Bt'
plants, which are genetically modified to produce a toxin that kills
insects but is harmless to birds and mammals.
The Chinese team, led by Jingxue Wang of the Agri-Biotechnology Research
Centre of Shanxi Province, inserted two genes at once to overcome this
The gene from the Asian scorpion (Buthus martensii) produces a poison
that specifically affects insect nervous systems, leading to paralysis.
The gene from the tobacco hawkmoth (Manduca sexta) produces a chemical
that breaks down chitin, a major component of insects' outer surface and
Because it is unlikely that a caterpillar would be able to resist both
toxins at once, the researchers say their approach could slow down and
minimise the chance of an insect developing resistance to the plants.
They also suggest using their approach in combination with the Bt toxin
genes already widely used.
Lead researcher Wang, told SciDev.Net the team is trying the same
combination of genes in GM cotton.
Eric Messens, a professor of plant molecular genetics at Flanders
Interuniversity Institute for Biotechnology at Ghent University,
Belgium, warns however that some scorpion toxins previously thought to
affect only insects can also affect mammals.
He told SciDev.Net that detailed studies must be conducted to see
whether the toxins produced by the GM plants affect human health.
Another concern about GM oilseed rape is that insects or the wind could
carry pollen with foreign genes into non-GM oilseed rape crops or
"Discussions about biosafety should be based on the results of practical
case studies and not on worst case scenarios," says Gerhard Schwarz, a
researcher at the Germany-based EpiGene company.
Schwarz and colleagues published a two-year field study of GM oilseed
rape online in the European Journal of Agronomy on 21 June.
The team found that genetic contamination of non-GM plants with GM genes
could be kept below the 0.9 per cent level required by European food
labelling rules, without limiting the distance between the two sets of
"Our results showed that the gene flow by pollen dispersal can be
brought under control and does not lead to a biological catastrophe,"
Schwarz told SciDev.Net.
GM crops can therefore co-exist with conventional and organic farming,
Link to abstract of paper in Plant Cell Report
Reference: Plant Cell Report doi: 10.1007/s00299-005-0967-3
Link to abstract of paper in European Journal of Agronomy
Reference: European Journal of Agronomy doi: 10.1016/j.eja.2005.04.002
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