Ozone induces flavonol production of Ginkgo biloba cells dependently on nitrate reductase-mediated nitric oxide signaling

• Published in: Environmental and experimental botany 2012, Vol.75, p.114-119
• Main Authors: Xu, Maojun, Zhu, Yun, Dong, Jufang, Jin, Haihong, Sun, Lina, Wang, Zhian, Lu, Zhonghua, Zhang, Ming, Lu, Dan
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Flavonol; Flavonol accumulation; flavonols; Fundamental and applied biological sciences. Psychology; Ginkgo biloba; Ginkgo biloba cells; nitrate reductase; Nitrate reductase (NR); Nitrates; nitric oxide; Nitric oxide (NO); nitroprusside; Ozone; Ozone tolerance; potassium; secondary metabolites; single nucleotide polymorphism
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2011.09.005

► Ozone exposure induces flavonol accumulation and NO generation. ► NO is essential for ozone-induced flavonol. ► NR is responsible for ozone-triggered NO generation. ► Ozone-induced flavonol production is dependent on NR-mediated NO signaling. Accumulation of secondary metabolites and nitric oxide (NO) generation are two early responses of plants to ozone exposure. However, the role of NO in ozone-induced secondary metabolite accumulation and the source of ozone-triggered NO generation are largely unknown. Here, we report that ozone exposure induces flavonol accumulation and NO generation of Ginkgo biloba cells. Pretreatment of the cells with NO specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium (cPTIO) inhibits the ozone-induced flavonol production of the cells, showing that NO is essential for ozone-induced flavonol accumulation. Moreover, ozone exposure significantly enhances nitrate reductase (NR) activity of the cells. Application of NR inhibitors not only suppresses ozone-triggered NR activity but also inhibits ozone-induced NO generation, showing that ozone may induce NO generation dependently on NR activity. Furthermore, treatment of the cells with NR inhibitors suppresses the ozone-induced flavonol production and the suppression of NR inhibitors on ozone-induced flavonol production can be reversed by exogenous application of NO via its donor sodium nitroprusside (SNP). Together, our results suggest that the NR-mediated NO signaling is involved in ozone-induced flavonol production of G. biloba cells.