Regulation of secondary metabolites of basil (Ocimum basilicum L.) by the application of elicitors in vivo

The aim of this study is to investigate the effect of exogenous application of two of the most important phytohormones as elicitors, methyl jasmonate (MeJa) and salicylic acid (SA) on the volatile accumulation and spectrum of basil (Ocimum basilicum L.). The first experiment was carried out in a greenhouse in Budapest. A total of 10 plants in vegetative developmental stage were chosen for each treatment and each dosage. The second experiment was established in an open field plot at the experimental station of MATE University in Budapest. Two dosages (0.1 and 2 mM) of each elicitor were applied twice with an interval of one week. After a week from the second treatment, aerial parts of the plants were harvested. The foliar application of the treatments enhanced the biosynthesis of the volatiles regardless of the type of elicitor or the dosage applied in both experiments. Moreover, the GC/MS analysis of basil oil revealed that the elicitors also influenced the chemical composition. MeJa exhibited more changes in the ratio of the components in the open field experiment, while SA caused the highest change in the greenhouse trial, including an increase of 418 and 119% in 1,8-cineole and linalool, respectively with the lower dosage (0.1 mM). Our results suggest that elicitation in-vivo may be used as a tool to influence the accumulation of secondary compounds. However, the elicitation does not depend only on the type of elicitor, but also on the dosage used, the type of the accumulated compound, the cultivar, and the growing conditions.