Nanoelicitors with prolonged retention and sustained release to produce beneficial compounds in wines

Abstract

Methyl jasmonate (MeJ), an elicitor able to trigger plant defence responses, is a natural and clean alternative to the use of hazardous pesticides. However, the efficient application of MeJ in fields is very limited due to its poor water solubility, thermal stability and phytotoxicity at the high dose required to produce beneficial effects in plants. Here, a novel nanoelicitor (nano-MeJ) was prepared through the functionalization of biocompatible calcium phosphate nanoparticles. The resulting nanocomposite produced a significant increase of beneficial compounds (phytoalexins) in grapes and wines at low MeJ dosage. Indeed, results from in vivo field experiments on Monastrell vineyards (Vitis vinifera L.) revealed that grapes treated with nano-MeJ provided red wines with high content of beneficial stilbenes, similar to the levels obtained with conventional treatments but applying 10 times higher MeJ dosage. We demonstrated that the nanoparticles protect and retain MeJ on the surface of the leaves over long periods of time. This protective action along with the slow release provides a prolonged supply of the resistance-inductor elicitor through the leaves, resulting in a significant efficiency increase. Additionally, the nanocomposite was stable for long periods of time (more than 175 days) and exhibited lower cytotoxicity compared to MeJ, which are important features for its efficient and safe use in agriculture.