Volume: 4, 2025
4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: P015
DOI: https://doi.org/10.24326/ICDSUPL4.P015
Published online: 9 April 2025
ICDSUPL, 4, P015 (2025)
Metabolic response of Melissa officinalis and Hypericum perforatum to the foliar application of salicylic acid
Maria Stasińska-Jakubas1*, Barbara Hawrylak-Nowak1
1 Department of Botany and Plant Physiology, Faculty of Environmental Biology, University of Life Sciences in Lublin, Akademicka 15, 20-950 Lublin, Poland
* Corresponding author: maria.jakubas@up.lublin.pl
Abstract
Salicylic acid (SA) is a phytohormone involved in plant defense responses. Its ability to modulate metabolic pathways and enhance the biosynthesis of specialized metabolites can be used to optimize the production of valuable bioactive compounds in medicinal plants. The study investigated the eliciting effects of foliar-applied SA on the physiology and secondary metabolism of lemon balm (Melissa officinalis L.) and St. John’s wort (Hypericum perforatum L.). The experiments were conducted in pot culture under controlled phytotron conditions. The plants were treated with an aqueous SA solution (150 mg/L; 10 mL/pot) and 10 days after the SA application selected physiological and phytochemical parameters were analyzed. The concentration of total phenolic compounds in the leaves of the SA-treated plants varied between species – the induction of these metabolites was more pronounced in lemon balm (80% increase) than in St. John’s wort (16%). SA also enhanced the accumulation of total flavonoids, increasing their concentration by 61% and 48% in lemon balm and St. John’s wort, respectively. Due to the distinct metabolic profiles of the compared species, phenolic acids dominated the chemical composition in lemon balm, whereas flavonoids were the predominant metabolites in St. John’s wort. In lemon balm, SA treatment stimulated the accumulation of rosmarinic acid and its hexoside, with increases of up to 107% and 10-fold, respectively. The level of salvianolic acid A also increased, reaching 73% above the control, while caftaric acid and its hexoside concentrations more than doubled after SA exposure. In St. John’s wort, SA treatment promoted flavonoid biosynthesis, increasing the levels of rutoside (58%), quercetin (48%), and hyperoside (40%). SA spraying increased the content of neochlorogenic acid by 41%, but did not affect the levels of naphthodianthrones or phloroglucinols. No signs of toxicity due to SA application were observed; however, SA-induced metabolic changes were accompanied by oxidative stress-related responses (increased H2O2 and O2⁻˙ accumulation, lipid peroxidation, modulation of enzymatic antioxidant activity). These changes suggest that SA-induced eustress indicates an oxidative burst that is likely to contribute to enhanced secondary metabolite production without negatively affecting plant physiology. These findings highlight the potential of SA elicitation as a strategy for optimizing the production of secondary metabolites in medicinal plants.
Keywords: elicitation, secondary metabolites, lemon balm, St. John’s wort, phytochemistry
How to cite
M. Stasińska-Jakubas, B. Hawrylak-Nowak, 2025. Metabolic response of Melissa officinalis and Hypericum perforatum to the foliar application of salicylic acid. In: 4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL4.P015