葡萄叶片芪类物质积累对UV-C氧化胁迫的响应作用

The Role of Stilbenes Accumulation in Response to Oxidative Stress by UV-C in Grape Leaves

【目的】紫外引起葡萄叶片芪类物质白藜芦醇积累是一种常见的辐射效应,研究积累与UV-C引起的氧化胁迫关系。【方法】采用UV-C对离体红地球葡萄叶片进行胁迫;应用荧光照相与HPLC分析芪类物质变化特征,利用RT-PCB分析其生物合成途径基因表达规律,DAB检测叶片活性氧水平,分光光度法测定丙二醛水平,依文思蓝检测叶片细胞死亡程度。【结果】以22.5(W.h)/cm^2UV-C辐射叶片后白藜芦醇的含量最大,达到158μg/g鲜重。同一叶片左右差异明显,辐射处理一侧芪类物质含量、活性氧水平和细胞死亡程度明显高于未处理一侧;经辐射后的叶片中的MDA含量高于对照组;加抗氧化剂CAT和NAC可明显降低UV-C对白藜芦醇诱导效果。【结论】UV-C辐射导致离体红地球葡萄叶片氧化胁迫受损,其变化在空间和时间上与芪类物质白藜芦醇积累密切相关。

[ Objective] It is a common effect that UV radiation causes resveratrol accumulation in grape leaves, so the relationships between oxidiative stress and resveratrol production by UV - C become an object of present study. [ Method ] The detached leaves of grapevine （ Vitis vinifera L. cv. Red Globe） were treated by UV -C to display their differences on stilbene produced sites and contents via HPLC and fluorography assay. To evaluate the biosynthetic regulation of those stilbenes, the key enzyme genes in their biosynthetic pathway were semi -quantified by RT -PCR. ROS levels were detected by DAB stain. Malondialdehyde levels were analyzed by spectrophotometry assay. Foliar cell death was tested by Evans Blue stain. [ Result ] It was found in 22.5 W · h/cm^2 UV - C radiation leaves of grapevine after 24 h maximum content of resveratrol reached 158 μg / g fresh weight. Both treated and un - treated sides of leaves showed obvious differences which were reactive oxygen species level, cell death rates and stilbene contents in the UV -C treated -side were siguificandy higher than those of untreated - side. So were the MDA contents. ROS scanvagers CAT and NAC signif- icantly reduced resveratrol content in UV -C treatments. [ Conclusion] In all, foliar injury caused by UV - C treatment in grape leaves in vitro attributed to both oxidative stress and resveratrol in space and time - dependant manner closely.