褪黑素对秦艽原生质体抗UV-B环境胁迫的作用  

Defend Effects of Melatonin on Protoplasts of Gentiana macrophylla Under UV-B Irridiation

作　　者：张来军[1] 贾敬芬[2] 梅康[1] 林德丽 

机构地区：[1]琼州学院生物科学与技术学院,海南三亚572022 [2]西北大学生命科学学院,陕西西安710069

出　　处：《核农学报》2015年第5期830-835,共6页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金(31260139);海南省自然科学基金(313050);三亚市院地科技合作项目(2012YD37);琼州学院博士科研启动基金项目(QYXB201203);2012国家级大学生创新创业计划项目

摘　　要：为探讨褪黑素对UV-B辐射后的秦艽原生质体的影响,本研究采用单细胞凝胶电泳技术检测秦艽原生质体DNA损伤程度,选取尾部DNA含量（Tail DNA%）作为DNA损伤程度的分析指标。MEL以0、1、10μmol·L^-1的终浓度加入原生质体悬液中,UV-B辐射处理的辐照度为0.5 W·m^-2。试验分2组：1）原生质体分别用UV-B辐射处理不同的时间（0、5、10、30、60、120 s）,暗培养60 min后电泳。2）原生质体被UV-B照射40 s后,分别暗培养不同时间（0、1、2、3、4、6 h）,再电泳。结果显示在5~30 s的时间内,辐射时间越长,Tail DNA%越高,相同的辐射时间下,MEL浓度越高,Tail DNA%越低;在1~6 h培养时间内,MEL处理的样品,Tail DNA%值均低于阳性对照组,并且Tail DNA%值的大小与所处理的MEL的浓度呈反比关系。由此可见褪黑素降低了UV-B辐射诱导的植物原生质体DNA损伤程度,促进DNA损伤的修复。本试验应用SCGE技术,进一步揭示了MEL在植物抗环境胁迫中所起到的促进作用。Comet assay, named single cell gel electrophoresis assay （ SCGE）, was used to analyze the effect of melatonin （MEL） on the DNA repair ability of Gentiana macrophylla Pall. protoplasts. Cell was irradiated with different doses of ultraviolet-B radiation, DNA damage is indicated by Tail DNA%. MEL was added to the protoplast suspension at 0, 1, 10 μmol·L^-1 final concentration, the irradiance of UV-B is 0.5 W·m^-2. Experiment was divided into two parts. The first group, protoplasts was radiated by UV-B with different times （0, 5, 10, 30, 60, 120 s） and incubated in the dark 60 min, electrophoresis. The second group, protoplast was irradiated by UV-B 40 s and incubated in the dark with different times（0,1,2,3, 4,6h）, and then electrophoresis. In the range of 5 to 30 s, the same radiation dose, the higher concentration of MEL, the lower TailDNA%. After cells were cultured for 1 to 6 hours, TailDNA% which the samples was treated with MEL were always lower than the positive control＇ s, and the TailDNA% showed an inverse relationship with MEL concentration. A dose-related protective effect of MEL was observed in our experiment and MEL reduces damage of cells after irradiation by UV-B, promote the repair of DNA. In the study, the first use of SCGE technology further revealed that MEL improved the resistance of plant to environmental stress.

关 键 词：褪黑素 单细胞凝胶电泳 原生质体 秦艽 UV-B 

分 类 号：Q945[生物学—植物学]