水杨酸诱发的NO介导了丹参悬浮培养细胞中丹酚酸B的生物合成

水杨酸(SA)可诱导丹参悬浮培养细胞中一氧化氮(NO)产生、苯丙氨酸解氨酶(PAL)活化及丹酚酸B(Sal B)的生物合成。为了阐明NO对丹参悬浮培养细胞中Sal B生物合成的影响及作用机理,本实验利用NO供体硝普钠(SNP)、NO合成酶抑制剂L-NNA(Nω-nitro-L-arginine)、NO淬灭剂c PITO(carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide)以及PAL抑制剂L-AOPP(L-2-aminooxygen-3-phenyl acrylic acid)分别处理丹参悬浮培养细胞,并对其胞内NO水平、PAL活性和Sal B积累量进行了检测。结果表明,硝普钠(SNP)处理显著促进了NO产生、PAL活性和Sal B的积累,而L-NNA和c PITO抑制上述过程,说明NO诱发PAL活性提高并参与了SA诱导的Sal B生物合成;L-AOPP显著抑制了PAL活性及Sal B积累,却对NO产生没有显著影响,揭示NO位于PAL的上游。这说明SA诱发的NO产生、PAL活化及Sal B合成之间存在因果关系,即NO通过激活PAL触发Sal B生物合成。

Nitric Oxide Triggered by Salicylic Acid Mediates the Biosynthesis of Salvianolic Acid B in Salvia miltiorrhiza Suspension Cell Culture

Salicylic acid (SA) induced nitric oxide (NO) generation, Phenylalanine ammonia-lyase (PAL) activation, and salvianolic acid B (Sal B) biosynthesis. To determine the role of NO in SA-induced Sal B biosynthesis, the effects of NO donor sodium nitroprusside (SNP), NO synthase inhibitor L-NNA(N^ω-nitro-L-arginine), NO scavenger carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPITO), and PAL inhibitor L-AOPP (L-2-aminooxygen-3-phenyl acrylic acid) on SA-induced NO generation, PAL activation, and Sal B accumulation were studied individually. Pretreatment of the cells with SNP increased SA-induced NO generation, PAL activation and Sal B accumulation, which suggested that NO activated PAL and was involved in SA-induced Sal B biosynthesis. L-AOPP suppressed PAL activity and Sal B accumulation, but did not affect SA-induced NO generation, indicating that NO acted as an upstream signal of PAL. Results indicated that there was a causal relationship between SA-induced NO generation, PAL activation, and Sal B biosynthesis in Salvia miltiorrhiza suspension cell culture. Via activation of PAL, NO mediated the SA-induced Sal B biosynthesis.