Effect of Nitric Oxide on the Secondary Metabolites of <i>Taxus chinensis</i> var. <i>mairei</i> under UV-B Exposure

Abstract

In this paper, the effect of nitric oxide (NO) on the secondary metabolites of Taxus chinensis var. mairei under elevated UV-B radiation was studied. The 5-year-old seedlings were used as test materials. The sodium nitroprusside (SNP) was as the NO donor and Carboxy-PTIO potassium salt (cPTIO) as the NO scavenger. The results showed that the SNP, UV, UV-B+SNP treatments significantly increased the contents of photosynthetic pigments (p<0.05). The contents of chlorophyll a, chlorophyll b, carotenoid and total chlorophyll exhibited CK < cPTIO < UV-B+cPTIO < UV-B < SNP < UV-B+SNP. SNP, cPTIO, UV-B, UV-B+SNP and UV-B+cPTIO significantly increased the concentrations of flavonoids, condensed tannins, total phenolics and taxol (p<0.05). Spraying SNP and cPTIO had significant effect on the taxol concentration (p<0.05). The concentrations of flavonoids, condensed tannins, total phenolics and taxol reached the maximum under the UV-B+cPTIO treatment. Spraying different concentrations of SNP or cPTIO might affect the NO content in plants, and then impact on the secondary metabolism, which mechanism needs further investigation.