温度对UV-B诱导的烟草叶圆片DNA损伤的影响

环丁烷嘧啶二聚体(CPD)和6-4光产物(6-4PP)是两种主要的UV-B诱导的DNA光损伤产物。利用单克隆抗体酶联免疫吸附分析法(ELISA),研究了温度对UV-B诱导的烟草叶圆片DNA损伤的影响。室温(24℃)条件下,UV-B处理引起了烟草叶圆片DNA中CPD和6-4PP的积累。0℃条件下,UV-B处理的烟草叶圆片DNA中CPD和6-4PP的积累比室温下分别降低了9.8%和12%。UV-B诱导的DNA损伤曾被认为是纯粹的光化学过程而与不受温度影响,而本实验结果表明,UV-B诱导的烟草叶圆片DNA形成CPD和6-4PP的过程具有温度依赖性。这一特性有利于植物对全球变化的适应,因而具有重要的生态学意义。

Temperature effects on the formation of DNA damage in Nicotiana tabacum leaf discs induced by UV - B Irriadiation

Cyclobutane pyrimidine dimers(CPD) and 6-4 photoproducts(6-4PP) are two major kinds of photolesion induced by UV-B radiation in plants. By using ELISA method of with specific monoclonal antibodies, UV-B induced formation of CPD and 6-4PP in tobacco leaf discs at different temperatures was investigated. CPD increased during 4 h UV-B exposure. UV-B radiation induced formation of CPD and 6-4PP even at 0℃, but low temperature resulted in less damage. Contrary to the commonly accepted view that DNA damage induced by UV-B is temperature-independent because of its photochemical nature, we have thus found that UV-B-induced formation of CPD and 6-4PPin tobacco leaf discs is temperature-dependent.