绿豆幼苗UV-B敏感性与环丁烷嘧啶二聚体累积的关系

Cyclobutyl Pyrimidine Dimer Accumulation in Ralation to UV-B Sensitivity in Mung Bean Cultivars

【目的】明确绿豆品种间UV-B敏感性的差异与环丁烷嘧啶二聚体(CPDs)累积间的关系。【方法】采用单克隆抗体ELISA法,研究0.4W·m-2UV-B对两绿豆品种中绿-1和秦豆-20(PhaseolusraditusL.cv.Zhonglü-1andQindou-20)幼苗叶片DNA链内环丁烷嘧啶二聚体(CPDs)的诱导形成及其光、暗修复,并对CPDs累积与绿豆UV-B敏感性的关系进行分析。【结果】两品种绿豆幼苗经UV-B处理4d后,中绿-1叶片的生物量和净光合速率被抑制的程度明显低于秦豆-20,说明中绿-1对UV-B的敏感性低于秦豆-20。相应中绿-1叶片DNA中CPDs累积量和其形成能力也都低于秦豆-20,光修复能力明显高于秦豆-20,而两品种CPDs的暗修复能力基本相同,且均显著低于光修复能力。【结论】两品种幼苗CPDs形成能力和光修复能力的不同造成了两品种幼苗叶片在可见光下CPDs累积量的不同,进而可能导致了绿豆品种间UV-B敏感性的不同。另外,两品种CPDs形成能力的差异与紫外吸收物质含量有关。

[ Objective ] The purpose of the experiment is to reveal the relationship between cyclobutyl pyrimidine dimers （CPDs） accumulation and UV-B sensitivity in mung bean cultivars. [Method] Two mung bean cultivars （Phaseolus raditus L. cv. Qindou-20 and Zhonglü-1） were grown in greenhouse with treatment or without treatment of UV-B radiation （0.4 W·m^-2） for four days. The UV-B-induced CPDs in mung bean DNA were quantified by enzyme-linked immunosorbent assay （ELISA） with specific monoclonal antibody and the relationship between CPDs accumulation and the UV-B sensitivity of mung bean seedlings were discussed. [Result] The UV-B-induced inhibition of the biomass and net photosynthetic rate of the primary leaves of cultivar Zhonglü-1 were respectively lower than that of cultivar Qindou-20, so that the cultivar Zhonglü-1 was more tolerant to UV-B than the cultivar Qindou-20. Meanwhile, the cultivar Zhonglü-1 had lower CPD accumulation and susceptibility to CPD induction, higher photorepair capacity and same dark repair capacity as compared with the cultivar Qindou-20. [Conclusion] Different UV-B sensitivities between two mung bean cultivars may be mainly caused by the differences in CPD accumulation, which are caused by the different susceptibility to CPD induction and the different photorepair capacities. In addition, the different susceptibility to CPD induction between two mung bean cultivars is related to the different levels of UV-absorbing compounds.