Gong Yan-Wen, Yuan Ying-Jin
Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, P.O. Box 6888, Tianjin 300072, PR China.
J Biotechnol. 2006 May 17;123(2):185-92. doi: 10.1016/j.jbiotec.2005.11.003. Epub 2005 Dec 15.
The importance of nitric oxide (NO) in regulating plant cell responses to environmental stresses is becoming evident. Here the possible role of NO in suspension cultures of Taxus cuspidata under shear stress was investigated in a Couette-type shear reactor. It was found that shear stress with 190 s(-1) caused NO generation in 8 h. NO formation can be inhibited by N-nitro-L-arginine, a nitric oxide synthase inhibitor. Moreover, the activity of glutathione S-transferase (GST), a principal enzyme responsible for detoxification, decreased during shear stress. This inactivation partially recovered when NOS inhibitor or NO scavenger was added into cell cultures during shear stress. Treatment with reactive nitrogen species (RNS) also caused inactivation of GST in cells. The results indicate that NO plays a crucial role in GST inactivation in Taxus cuspidata cells under shear stress.
一氧化氮（NO）在调节植物细胞对环境胁迫的反应中的重要性正变得日益明显。在此，在库埃特型剪切反应器中研究了NO在东北红豆杉悬浮培养物应对剪切应力时可能发挥的作用。结果发现，190 s⁻¹ 的剪切应力在8小时内会导致NO生成。一氧化氮合酶抑制剂N-硝基-L-精氨酸可抑制NO的形成。此外，谷胱甘肽S-转移酶（GST）作为负责解毒的主要酶，其活性在剪切应力作用期间会降低。当在剪切应力作用期间向细胞培养物中添加一氧化氮合酶抑制剂或NO清除剂时，这种失活会部分恢复。用活性氮物质（RNS）处理也会导致细胞中GST失活。结果表明，在剪切应力作用下，NO在东北红豆杉细胞中GST失活过程中起着关键作用。
