Abstract :
[en] Consequently with the pressure exerted by chemical pesticides on environment, and the
awakening of politics, the demand for bio-pesticides is increasing. Nevertheless, supply is not
sufficient, and moreover those products are not competing enough.
In this context, the aim of this research is to set up a biological insecticide, which is
economic, with vegetal proteins resulting from alimentary industry, here the pea, Pisum
sativum L.. A group of proteins, which is quite easy to highlight, is present in relatively
important proportions (2%) in pea seeds, it’s the lectins class. Insecticidal effects of lectins
from different organisms have already been proved. Indeed, by binding to membrane glycosyl
groups of digestive tract cells, lectins can be very toxic for a lot of insects. Thus initially we
focus our investigations on Pisum sativum lectins (PSL).
First, PSL have been localised within the industrial process among different extraction juices.
Then, a chromatography has been performed on the selected juice with FPLC technology.
Although the matrix used for this chromatography, sephadex G75, is a banal bed for gel
filtration, it is in this case a real combination between classical gel filtration and affinity
chromatography. Indeed due the particular properties of lectins, they fixed carbonyl group of
the bed and have to be eluted after the filtration part with a solution of glucose. Then the
collected fractions corresponding to UV-peaks on the chromatogram were separated by
electrophoresis 2D and identified by mass spectrometry (ESI MS/MS) coupled with data bank
investigations.
Secondly bioassays using artificial diets have been developed on Myzus persicae in the aim to
study the aphicid effects of theses fractions with rm and LC50.These estimators show
significant mortality rates but also change in the fecundity and in the development of nymph.
