Phenolics and terpenoids change in response to yeast extract and chitosan elicitation in Zataria multiflora cell suspension culture

Abstract

Zataria multiflora is an important medicinal plant with antioxidant and anticancer properties attributed to its phytochemicals. To develop a method for bulk production of valuable phytochemicals, cell suspension culture of Z. multiflora were grown in liquid B5 medium and then treated in their log growth phase with chitosan (0, 10, 20, and 40 mg L⁻¹) and yeast extract (0, 400, 800, and 1200 mg L⁻¹) for 3 days. The levels of hydrogen peroxide (H₂O₂), nitric oxide (NO), malondialdehyde (MDA), and the main terpenoids and phenylpropanoids in the cell extracts were determined by HPLC and spectrophotometric techniques. The H₂O₂ and MDA levels significantly increased in the cells treated with both yeast extract and chitosan, while the NO level increased in those exposed to yeast extract. At their highest concentrations, both elicitors significantly increased PAL and TAL activities, as well as phenolic acids and flavonoids contents. Chitosan only induced the production of caffeic acid (22 µg g⁻¹ DW), benzoic acid (2 µg g⁻¹ DW), 4-hydroxy benzoic acid (6 µg g⁻¹ DW), epicatechin (63 µg g⁻¹ DW), and apigenin (5 µg g⁻¹ DW) in the cells, while yeast extract increased the contents of phenylpropanoids gallic acid (50 µg g⁻¹ DW), vanillin (35 µg g⁻¹ DW), salicylic acid (24 µg g⁻¹ DW), catechin (130 µg g⁻¹ DW) and terpenoids carvacrol (7 µg g⁻¹ DW) and thymol (24 µg g⁻¹ DW). In conclusion, changes in the production of phenolics and terpenoids are a defensive mechanism in Z. multiflora cells treated by yeast extract and chitosan.