Hydrogen Peroxide and Nitric Oxide are Involved in Salicylic Acid-Induced Salvianolic Acid B Production in Salvia miltiorrhiza Cell Cultures

摘要

Hydrogen peroxide (H₂O₂) and nitric oxide (NO) are key signaling molecules in cells whose levels are increased in response to various stimuli and are involved in plant secondary metabolite synthesis. In this paper, the roles of H₂O₂ and NO on salvianolic acid B (Sal B) production in salicylic acid (SA)-induced Salvia miltiorrhiza cell cultures were investigated. The results showed that H₂O₂ could be significantly elicited by SA, even though IMD (an inhibitor of NADPH oxidase) or DMTU (a quencher of H₂O₂) were employed to inhibit or quench intracellular H₂O₂. These elicited H₂O₂ levels significantly increased NO production by 1.6- and 1.46 fold in IMD+SA and DMTU+SA treatments, respectively, and induced 4.58- and 4.85-fold Sal B accumulation, respectively. NO was also markedly elicited by SA, in which L-NNA (an inhibitor of NO synthase) and cPTIO (a quencher of NO) were used to inhibit or quench NO within cells, and the induced NO could significantly enhance H₂O₂ production by 1.92- and 1.37-fold in L-NNA+SA and cPTIO+SA treatments, respectively, and 3.27- and 1.50-fold for Sal B accumulation, respectively. These results indicate that elicitation of SA for either H₂O₂ or NO was independent, and the elicited H₂O₂ or NO could act independently or synergistically to induce Sal B accumulation in SA-elicited cells.