H2O2参与水杨酸诱导丹参培养细胞中丹酚酸B合成的信号转导

Hydrogen peroxide is involved in the signal transduction of salicylic acid-induced salvianolic acid B biosynthesis in Salvia miltiorrhiza cell cultures

摘要:

过氧化氢 (Hydrogen peroxide, H2O2) 为活性氧 (Reactive oxygen species，ROS) 的一种，存在于许多生物体系中并介导植物中多种生理和生化过程。为了探讨H2O2作为信号分子在水杨酸 (Salicylic acid, SA) 诱导丹参培养细胞合成丹酚酸B (Salvianolic acid B, Sal B)过程中的作用，分别考察了SA和H2O2、过氧化氢酶 (Catalase，CAT)、二甲基硫脲 (2-(4-carboxy-2-phenyl)-4,4,5,

Abstract:

Hydrogen peroxide (H2O2), one of reactive oxygen species, is widely generated in many biological systems, and it mediates various physiological and biochemical process in plants. To investigate the role of H2O2 as a signaling molecule in the process of salicylic acid (SA)-induced Salvianolic acid B (Sal B) accumulation, we separately inspected the cultured cells of Salvia miltiorrhiza with SA, H2O2, Catalase (CAT), 2-(4-carboxy-2-phenyl)-4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide (DMTU) and Imidazole (IMD) to investigate the influence on the activity of phenylalanine ammonia-lyase (PAL) and tyrosine aminotransferase (TAT) and the accumulation of Sal B. Treatment of S. miltiorrhiza cells with SA resulted in an increase of H2O2, the increase of PAL and TAT and accumulation of Sal B. Exogenous application of 10~30 mmol/L H2O2 was found to effectively increase PAL and TAT activity as well as the Sal B content. CAT, a H2O2 scavenger, eliminated the Sal B-accumulating effects of exogenous H2O2 and SA. These indicated that H2O2 may serve as an upstream signaling molecule in the SA-induced accumulation of Sal B signal transduction pathway. Disposed by DMTU, a chemical trap for H2O2, as observed to be effective in inhibiting SA-induced accumulation of Sal B. IMD strongly inhibits the activity of NADPH oxidase, which is one of the main sources of H2O2 formation in plant cells. IMD treatment strongly inhibited the accumulation of Sal B in cultured cells of S. miltiorrhiza, but the effects of IMD, can be partially reversed by the exogenous SA. The accumulation of Sal B was blocked once the generation of H2O2 by NADPH oxidase was inhibited, and H2O2 served as signaling molecule mediated the SA-induced Sal B accumulation.