UV-B辐射对神农香菊萜类物质合成及其相关基因表达的影响

Effects of UV-B radiation on biosynthesis of terpenoids and expression of related genes in Chrysanthemum indicum var. aromaticum

关键词:  神农香菊, UV-B辐射, 萜类物质, 基因表达

Key words:  Chrysanthemum indicum var. aromaticum, UV-B radiation, terpenoid, gene expression

摘要:

该研究以神农香菊为材料,用强度为400 μw·cm^-2的紫外光UV-B对其进行辐射处理,辐射时间分别为0、0.5、1、2、4 h,探讨了UV-B辐射对神农香菊萜类物质合成及其相关基因表达的影响。结果表明:(1)较短时间的UV-B辐射对神农香菊萜类物质合成相关基因表达量有明显的促进作用。与对照相比,0.5、1、2、4 h处理对相关基因表达量均有不同程度的提高; 在2 h处理下HMGR、DXR、TPS、GPS基因的相对表达量达到最大值,在4 h处理下FPS和DXS的相对表达量达到最大值,其中FPS基因表达量变化最显著,为对照的69倍。(2)MVA途径中,去氢白菖烯、杜松萜烯的含量与FPS基因表达量4 h内持续上升的变化趋势保持一致,1-石竹烯与HMGR的变化趋势保持一致,表现为先升高后降低。(3)MEP合成途径中,α-侧柏酮、崖柏酮、β-侧柏酮的含量呈现与DXR、GPS、TPS基因表达量相同的变化趋势,桉树脑在UV-B辐射4 h内持续上升,与DXS基因的变化一致。由此可以推断,UV-B辐射通过影响各自途径中一些关键基因的表达量,进而影响了神农香菊萜类物质的合成量。

Abstract:

In this study, Chrysanthemum indicum var. aromaticum was used as material. We examined the changes of biosynthesis of terpenoid and expression of related genes in C. indicum var. aromaticum following the treatment of different durations(0, 0.5, 1, 2, 4 h)of 400 μw·cm^-2 UV-B radiation. The results were as follows:(1)The short time of UV-B radiation could significantly promote the expression of related genes in C. indicum var. aromaticum. Compared with the control, 0.5, 1, 2, 4 h treatment of UV-B radiation increased the expression of related genes. Meanwhile, relative expressions of HMGR, DXR, TPS, GPS reached the peak after two hours' treatment of UV-B radiation. As well as the relative expressions of FPS and DXS reached the maximum at four hours' treatment. A significant increase in FPS gene expression was found when plant exposed to four hours of UV-B duration(69 times compared with control).(2)In mevalonate pathway(MVA), the contents of calamenene, cadinene increased following the change of FPS gene expression during four hours of UV-B radiation. The change of the content of 1-caryophyllene was consistent with the change of HMGR gene expression, which increased first and then decreased.(3)In the pathway of 2-methyl-D-erythritol-4-phosphate(MEP), the contents of α-thujone, thujone and β-thujone showed the same trend as the expressions of DXR, TPS and GPS. The content of cajuputole generally increased during four hours' treatment responding to the change of DXS gene expression. In summary, the data indicate that UV-B radiation can change the regulation of terpenoid biosynthesis in C. indicum var. aromaticum by affecting some key genes' expressions.