Nitric Oxide Regulates Shikonin Formation in Suspension-Cultured Onosma paniculatum Cells

S.-J. Wu, J.-L. Qi, W.-J. Zhang, S.-H. Liu, F.-H. Xiao, M.-S. Zhang, G.-H. Xu, W.-G. Zhao, M.-W. Shi, Y.-J. Pang, H.-G. Shen, Y.-H. Yang
2008 Plant and Cell Physiology  
Endogenously occurring nitric oxide (NO) is involved in the regulation of shikonin formation in Onosma paniculatum cells. NO generated after cells were inoculated into shikonin production medium reached the highest level after 2 d of culture, which was 16 times that at the beginning of the experiment, and maintained a high level for 6 d. A nitric oxide synthase (NOS) inhibitor, N ω -nitro-L -arginine ( L -NNA), and a nitrate reductase (NR) inhibitor, sodium azide (SoA), consistent with their
more » ... stent with their inhibition of NO biosynthesis, decreased shikonin formation signifi cantly. This reduction could be alleviated or even abolished by exogenous NO supplied by sodium nitroprusside (SNP), suggesting that the inhibition of NO biosynthesis resulted in decreased shikonin formation. However, when endogenous NO biosynthesis was up-regulated by the elicitor from Rhizoctonia cerealis , shikonin production was enhanced further, showing a dependence on the elicitor-induced NO burst. Real-time PCR analysis showed that NO could signifi cantly up-regulate the expression of PAL , PGT and HMGR , which encode key enzymes involved in shikonin biosynthesis. These results demonstrated that NO plays a critical role in shikonin formation in O . paniculatum cells.
doi:10.1093/pcp/pcn178 pmid:19022805 fatcat:6hepypkggjdpvfi4brh3shjlqq