Einfluss des Einsatzes von Pflanzenbehandlungsmitteln auf die Genexpression in Pflanzen

• Forschungsstelle: BAG
• Projektnummer: 02.000450

Schlüsselwörter (Deutsch)

Pflanzenschutzmittel
Genexpression

Kurzbeschreibung (Deutsch)

Bei der Sicherheitsbeurteilung von Pflanzenbehandlungsmitteln (PBM) stehen die toxikologischen Eigenschaften der eingesetzten Substanzen im Vordergrund. Weiter wird die Rückstandssituation beurteilt.
Inwieweit der PBM Einsatz aber zu Veränderungen im Stoffwechsel der Zielpflanzen führt, ist bis heute weitgehend ungeklärt, kann aber für die Beurteilung der Nahrungsmittelsicherheit von Bedeutung sein. Es ist eine ganze Reihe von Pflanzeninhaltsstoffen bekannt, deren Gehalte in den Pflanzen nahe an ihrer pharmakologisch/toxikologischen Wirkschwelle vorliegen.
Analytische Screening Methoden, die auf molekularer Ebene ein Gesamtbild von Metabolismusveränderungen geben würden, standen bis vor kurzem nicht zur Verfügung. Neuerdings gibt es aber solche Methoden, die ein Abbild von Stoffwechselveränderungen aufgrund von Genaktivierungs- und Gendeaktivierungsmustern liefern können

Projektziele (Deutsch)

Analyse der Genexpression des mit Fungiziden und Herbiziden behandelten Weizens und Vergleich der Genexpression Analyse mit der Chip-Technologiw.

Abstract (Deutsch)

Abstract (Englisch)

During this project, we wanted to achieve several objectives and milestones.
The first consisted in a technical part of the project to define better printing
conditions compared to our previous results with the GMS417 arrayer. The use
of DMSO in the printing buffer allowed good spot morphology on poly-L-lysine
coated slides as well as a reduction of the evaporation of the samples during
the printing process. Finally, the right parameters to print with our arrayer were
successfully found. These settings are really critical to achieve good
reproducibility of the hybridisation results and it often requires a long time to
find them.
In a second milestone for this period, we focused on monitoring the effects of
fungicide treatments on gene expression of field-grown wheat plants using
slides printed in Lausanne as we had not yet identified the right parameters for
our spotter at that time. The data analysis of this field experiment has given
dramatically different results compared to the one we had previously obtained
for the greenhouse trial. In the field, the treatment with the fungicides did not
induce any significant differential expression, in contrast to the greenhouse
trial. This is probably due to the growth conditions that were more stressing for
the plants grown in the field compared to the controlled conditions of the
greenhouse. We conclude from these data that (i) greenhouse trials are
probably not giving the relevant data for making any risk assessment of
agricultural technologies and (ii) that field plants are considerably more
stressed than greenhouse plants.
In addition, the confirmation of our results using another technique (RNA
blotting) which is well established in our laboratory allowed us to conclude that
our use of the microarray technique as well as the statistical normalisation
method that we are using are reliable. The experiment on fungicides is now
being finalised by the writing of a publication.
The second main part of our project consists of the analysis of the impact of
herbicides. The preliminary analyses of this experiment are promising with the
observation of differentially expressed genes 24hr after treatment. Here again,
like with the fungicide experiment, the defence-related genes are showing an
over-expression but mostly with the herbicide Lotus. The gene expression analysis remains to be done for the other time-points as well as the field
experiment comparison. These first results allow us to expect again interesting
responses from the wheat to the treatments with these phytochemical
compounds.

Umsetzung und Anwendungen (Deutsch)

Publikation in wissenschaftlichen Journals

Publikationen / Ergebnisse (Deutsch)

In Vorbereitung