چكيده لاتين
Dracocephalum polychaetum Bornm. is a medicinal herb belonging to the Lamiaceae family and is native to Iran, specifically from regions in the southern part of Kerman province. This study aimed to investigate the effects of different concentrations of yeast extract on the non-enzymatic antioxidant systems and the production of certain phytochemicals in the cell suspension of D. polychaetum. After callus induction, suitable callus was transferred to liquid MS medium supplemented with 0.2 mg/L BAP, 2 mg/L NAA, and 20 g/L sucrose, and incubated on a gyratory shaker at 120 rpm in the dark. Suspension-cultured cells were then treated with 0, 25, 50, 100, 150, and 200 ppm concentrations of yeast extract during their exponential growth phase (from day 8 to 12 after sub-culturing). The results showed that the activity of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), and the content of total phenolics, flavonoids, flavonols, anthocyanins, proline, phosphomolybdate, malondialdehyde (MDA), hydrogen peroxide (H2O2) content, and fresh weight in all treated cells had a significant difference from the control. The intracellular content of valuable phytochemical compounds, such as rosmarinic acid, p-coumaric acid, catechin, thymol, carvacrol, and quercetin, increased considerably in all treated cells. Taken together, these findings suggest that different concentrations of yeast extract induced various changes in cell metabolism through oxidative stress and could enhance non-enzymatic antioxidant defense systems, thereby inducing phenolic biosynthesis pathways and accumulation in these cells. The results indicate that 50 and 100 ppm of yeast extract positively affected cell growth and the total phenolic and phytochemical compound content. This demonstrates that the cell suspension of D. polychaetum is a suitable tool for producing phytochemical extracts under controlled and sterile conditions, and that yeast extract, as a biotic elicitor, can increase the production of phytochemicals.
