It is well known that β-(1→3)-glucans are able to enhance immune defense in mammals, so that these natural polysaccharides find applications for instance in immunotherapy to fight cancers. Rationalization of the observed effects comes from the discovery of receptors such as Dectin-1, CR3 . Interestingly, it was also shown that laminarin and sulfated derivatives thereof can be used in the bioprotection and/or biostimulation if the plant kingdom. Unfortunately, these efficiency is significantly limited both in standardized or real field conditions. One major explanation is probably a limited penetration through the leaf cuticle following spray application. We have demonstrated that penetration through leaves was improved thanks to formulation efforts and by spraying the solutions on abaxial surface .
In order to favor penetration bioactive laminarin in plants, we propose to present the synthesis of laminarin-conjugates characterized by (1) increased hydrophobicity (partial acylation with long chains, peracetylation, permethylation) of (2) the presence of negative charges (sulfation, carboxymethylation, sulfoxyethylation). The biological properties related to their elicitation or bioprotection , as well as biphotonic studies with luminescent derivatives, will be also presented.
- L. Legentil, F. Paris, C. Ballet, S. Trouvelot, X. Daire, V. Vetvicka, V. Ferrieres. Molecular interactions of β-(1→3)-glucans with their receptors. Molecules, 20 (2015) 9745-9766.
- F. Paris, Y. Krzyzaniak, C. Gauvrit, F. Jamois, F. Domergue, J. Joubes, V. Ferrieres, M. Adrian, L. Legentil, X. Daire, S. Trouvelot. An ethoxylated surfactant enhances the penetration of the sulfated laminarin through leaf cuticle and stomata, leading to increased induced resistance against grapevine downy mildew. Physiol. Plant 156 (2016), 338-350.