# New Chlormequat-Based Ionic Liquids as Plant Resistance Inducers

## TL;DR

Scientists created new plant-friendly compounds that help crops resist diseases better than traditional forms.

## Contribution

New chlormequat-based ionic liquids were synthesized and shown to induce plant resistance more effectively than acid forms.

## Key findings

- Chlormequat ionic liquids showed improved biological activity and lower phytotoxicity compared to acid forms.
- The compounds activated defense responses in tobacco and reduced susceptibility to viral infection.
- Salicylic acid and its derivatives were effective as resistance-inducing anions in the ionic liquids.

## Abstract

Active compounds used in agriculture are mainly in the form of acids. This applies primarily to substances that are inducers of systemic acquired resistance, which is one of the most promising methods of supporting plants in the fight against pathogens. The physicochemical properties and biological activity of such substances can be improved by derivatizing them to salt forms. We used the concept of ionic liquids to obtain novel compounds in the form of chlormequat ionic liquids. In this study we present synthesis and characterization of a series of novel ionic liquids composed of the chlormequat cation paired with plant resistance-inducing anions, including salicylic acid and its chlorinated derivatives, nicotinic acid and isonicotinic acid. The results indicate that the new compounds in the form of salts are characterized by better biological activity related to SAR induction and lower phytotoxicity compared to the parent compounds as their equivalents in acid forms. The obtained compounds demonstrated the ability to activate defense responses in tobacco and to reduce susceptibility to viral infection, highlighting their potential for further application in crop protection.