Effect of Choline Cation Derivatives on the Efficacy of Plant Resistance Inducers

Abstract

AbstractThis article presents the synthesis, physical properties, phytotoxicity, and SAR induction activity of 48 new ionic liquids composed of cations which are choline derivatives and anions of inducers such as salicylic acid, 2,6‐dichloroisonicotinic acid, and benzo[1.2.3]thiadiazole‐7‐carboxylic acid. The cations from which the reported salts were obtained differ in the length of the aliphatic chain bonded to the N,N‐dimethylethanolamine, N,N‐diethylethanolamine, and N,N‐dibutylethanolamine groups. Examination of the obtained series of compounds determined the correlation between the structure of the cation and the biological action of the resistance inducer and investigated the relationship between the structure of the cation and its phytotoxic effect on the plant. Systemic acquired resistance efficacy tests were performed on tobacco Nicotiana tabacum var. Xanthi infected by tobacco mosaic virus (TMV) and phytotoxic tests were performed on Agrimonia eupatoria seeds. The results indicate that the phytotoxicity of salts composed of the same cation increases with the introduction of anions in the following order: salicylate<2,6‐dichloroisonicotinate<benzo[1.2.3]thiadiazole‐7‐carboxylate. Efficacy tests of systemic acquired resistance conducted on tobacco plants show that the presented salts reduced the size of necrotic spots on TMV‐infected tobacco leaves by up to 100 % ([C10DMEA][BTHCOO] and [Allyl‐DEEA][BTHCOO]) compared to control (untreated) plants. The examples of salts composed of choline cation derivatives presented in this study indicate that changing the cation structure in most cases did not alter or increased the biological activity of the resulting salts with resistance inducer anions relative to their carboxylic acid counterparts.