An ethoxylated surfactant enhances the penetration of the sulfated laminarin through leaf cuticle and stomata, leading to increased induced resistance against grapevine downy mildew

• DOI: 10.1111/ppl.12394
• Publication Date: 2015-10-12T22:50:20Z
• Authors: Franck Paris; Yuko Krzyżaniak; Christian Gauvrit; Frank Jamois; Frédéric Domergue; Jérôme Joubès; Vincent Ferrières; Marielle Adrian; Laurent Legentil; Xavier Daire; Sophie Trouvelot
• Keywords: Plasmopara viticola; Penetration (warfare); Plant cuticle; Trichome; Cuticle (hair); Laminarin

Some β-1,3-glucans and particularly sulfated laminarin (PS3) are known as resistance inducers (RIs) in grapevine against the downy mildew. However, their efficacy vineyard is still often too low, which might be caused by a limited penetration through leaf cuticle following spray application. We used (14) C-sucrose uptake experiments with leaves order to select surfactant saccharide enhancer. Our results showed that although sucrose foliar was it strongly enhanced Dehscofix CO125 (DE), highly ethoxylated surfactant. Fluorescent saccharides were then produced laser scanning microscopy analyze diffusion pattern Arabidopsis thaliana grapevine. Interestingly, PS3 seemingly able penetrate only when formulated DE. Diffusion could preferentially occur via stomata, anticlinal cell walls trichomes. In grapevine, rate much higher on stomateous abaxial surface of than adaxial surface. Finally, using DE allowed level mildew control PS3, corroborated observations. have practical consequences for improvement treatments saccharidic grape. That is, formulation such RIs plays critical role cuticular consequently efficacy. Also, application should target maximize penetration.