Effect of salicylic acid and yeast extract on caffeic acid derivatives production in Echinacea purpurea L.

Purple coneflower, Echinacea purpurea (L.) Moench, has long been used in herbal remedies to prevent and treat a wide range of diseases like common cold, simple cough, pulmonary infections, dermatologic disorder and chronic diseases due to immunodeficiency.

The present study was conducted to investigate the effects of salicylic acid and yeast extract foliar application on caffeic acid derivatives production in coneflower.

Two factorial experiments were performed individually under greenhouse conditions during the years 2017-2018. In the first experiment, the effect of salicylic acid (0, 80, 160 and 320 mg/L) and each at four exposure times (24, 48, 72 and 96 hours) was studied. Also, in the second experiment, the effect of yeast extract (0, 0.75, 1 and 1.5 g/L) and each at four exposure times was investigated.

The results indicated that main effects and interactions of different concentrations of salicylic acid and yeast extract at different exposure times on caffeic acid derivatives content were significant (P ˂ 0.01). The highest cichoric acid, caftaric acid and echinacoside production was obtained after 96 hours of treatment at 160 mg/L salicylic acid treated plants. The highest cichoric acid production 7.150 mg/g DW was obtained after 96 hours of treatment at 1.5 g/L yeast extract treated plants, this was 3.58-fold higher compared to respective control. The lowest level of caffeic acid derivatives production was observed in control plants.

In conclusion, salicylic acid and yeast extract foliar application have a positive effect on caffeic acid derivatives production in Echinacea purpurea aerial parts.