Involvement of nitric oxide in oxidative burst, phenylalanine ammonia-lyase activation and Taxol production induced by low-energy ultrasound in Taxus yunnanensis cell suspension cultures.
This work was to characterize the generation of nitric oxide (NO) in Taxus yunnanensis cells exposed to low-energy ultrasound (US) and the signal role of NO in elicitation of plant defense responses and secondary metabolite accumulation. The US sonication (3.5-55.6 mW/cm(3) at 40 kHz fixed frequency) for 2 min induced a rapid and dose-dependent NO production in the Taxus cell culture, which exhibited a biphasic time course, reaching the first plateau within 1.5 h and the second within 7 h after US sonication. The NO donor sodium nitroprusside (SNP) potentiated US-induced H(2)O(2) production and cell death. Inhibition of nitric oxide synthase (NOS) activity by N(omega)-nitro-L-arginine (L-NNA) or scavenging NO by 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxyde (PTIO) partially blocked the US-induced H(2)O(2) production and cell death. Moreover, the NO inhibitors suppressed US-induced activation of phenylalanine ammonium-lyase (PAL) and accumulation of diterpenoid taxanes (Taxol and baccatin III). These results suggest that NO plays a signal role in the US-induced responses and secondary metabolism activities in the Taxus cells.
Wang
Jian Wen
JW
Department of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, PR China. jwwang@suda.edu.cn
Zheng
Li Ping
LP
Wu
Jian Yong
JY
Tan
Ren Xiang
RX
D000972:Antineoplastic Agents, Phytogenic / Q000096:biosynthesis*; D002478:Cells, Cultured; D004789:Enzyme Activation; D006861:Hydrogen Peroxide / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology*; D017239:Paclitaxel / Q000096:biosynthesis*; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism*; D016897:Respiratory Burst; D020946:Taxus / Q000166:cytology / Q000378:metabolism*
D000972:Antineoplastic Agents, Phytogenic; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D010650:Phenylalanine Ammonia-Lyase; D017239:Paclitaxel