Dear forum participants,
Few messages have been posted on the specific part of the guidance for
RA of LM crops tolerant to abiotic stress.
This is however a group of LMOs in extended development.
This specifice guidance surely pinpoints several pecularities of these
plants.
But, generally speaking, I agree with the comments of our Belgian
Biosafety Advisory Committee on this issue, saying that the roadmap
suffers of some redundancies and some lack of clarity and of coherence
concerning the successive steps to follow in the course of the RA and on
specific aspects to consider.
In particular, the complexity of the issue regarding the finding of
adequate comparators and adequate situations for comparative testing (
cf. section on "Challenges with respect to experimental design" p. 29 of
the final report of the AHTEG) could be more clearly explicited for
unexperimented users of the RA guidance ( see for some details the
comments of the Belgian Biosafety Advisory Committee sent to and posted
by the SCBD ).
Our experts also consider that a clear definition of "tolerance" could
be useful, to highlight the distinction between the wording "stress
tolerance" and "stress resistance"
This issue of GM plants tolerant to abiotic stresses is, with this of LM
mosquitoes, an issue that will particularly have to benefit from the
"living" aspect of the guidance and the necessity for further reflexion,
knowledge, experience, and methodologies development.
Presently, I notice that there is some discrepancy among expert opinions
concerning the potential higher ability of this type of LM plants to be
persistant and invasive.
A previous message ( from Paulo Paes de Andrade ) mentionned that the
concerned transgenic traits would give very limited tolerance, and would
not not allow the GM plants to propagate in a new environment , taking
moreover into account that most of cultivated plants cannot easily
propagate without our direct help.
By contrast, experts underline in the relevant comments of our Belgian
Biosafety Advisory Council that " there are significant connections
between both signalling pathways and the genes and molecules involved in
diverse abiotic stresses" and thus " it is likely that some modified
traits will cause increased tolerance to more than one abiotic stress".
This would rather suggest a larger potentiality of persistance and maybe
invasivity. In any case, it should be clear in the course of the RA what
are the intended effects of the transgenesis. Any other effects of
increased tolerance or other advantage or disadvantage given
simultaneaously or indirectly by the concerned transgenes should be
tested among "unintended" effects and looked at for their potential
safety concerns.
It would be good to give still some more attention in the guidance
concerning the pecularity in the general physiology/resistance/tolerance
changes of the plant that could induce a tolerance trait to a specific
abiotic stress.
Attention should also be given to the constitutivity or signal-induced
tolerance(s).
With best regards.
Lucette Flandroy
Disclaimer :
http://www.health.belgium.be/eportal/disclaimer/index.htm