Botrytis cinerea impact on copper-spatial distribution and speciation in grapevine leaves exposed to copper-based nanoformulations

The usage of Cu-based fungicides in agriculture is restricted in the EU (EU 2018/1981) due to soil contamination. There is an urgent need to enhance the efficiency of the allowed Cu dosages. Cu-based nanoparticles (Cu-NPs) can be an efficient fungicide alternative. They present higher leaf affinity than ionic Cu, drastically reducing Cu wash-off and subsequent application dose and frequency. In a previous session at the ESRF, we assessed the Cu-NPs transformations and spatial distribution at the leaf surface and in the plant after uptake. However, fungal infections will likely modulate the leaf surface microenvironment (pH modification) due to pathogen metabolites released while colonizing the leaf, likely changing Cu speciation and distribution in the leaf. We aim to understand the pathogen's impact on the possible Cu-species transformation and subsequent changes in its spatial distribution along with the associated adhesion and translocation.