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为探讨外源抗氧化剂对春石斛类原球茎(PLBs)超低温保存中氧化应激的缓解效应,以春石斛‘红梦幻’PLBs为试材,在玻璃化法超低温保存程序的不同环节导入3种不同浓度外源抗氧化剂,检测其对PLBs冻后存活率的影响,在此基础上分析最佳抗氧化剂介入实验体系中氧化应激相关指标的变化。结果显示,在装载、PVS2处理和去装载时导入不同浓度的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)对PLBs冻后存活率影响差异大,均以去装载时导入效果最好。其中SOD导入最佳浓度为600 U·m L-1,存活率提高了5.76%,但对氧化应激相关指标均无显著影响。CAT导入最佳浓度为400 U·m L-1,存活率提高了33.49%,显著降低过氧化氢(H2O2)和丙二醛(MDA)含量,提高抗坏血酸(As A)含量。在预培养、装载、PVS2处理和去装载时导入不同浓度的As A均可提高PLBs冻后存活率,以去装载时导入效果最好,最佳浓度为0.1 mmol·L-1,存活率提高了14.34%,显著降低了超氧阴离子(O2·–)产生速率和MDA含量,提高了SOD活性。结果表明,3种外源抗氧化剂对PLBs冻后存活率相对提高效果依次为CAT>As A>SOD。
In order to investigate the alleviating effect of exogenous antioxidants on the oxidative stress in the preservation of protocorm-like bodies of Dendrobium candidum (PLBs), three kinds of PLBs were introduced at different stages of vitrification cryopreservation procedure The effects of different concentrations of exogenous antioxidants on the survival rate of PLBs after freezing were investigated. Based on these, the changes of oxidative stress-related indexes in the optimal antioxidant intervention system were analyzed. The results showed that different concentrations of superoxide dismutase (SOD) and catalase (CAT) during loading, PVS2 treatment and de-loading resulted in significant differences in the post-thaw survival rates of PLBs it is good. The optimum concentration of SOD was 600 U · m L-1, the survival rate increased by 5.76%, but no significant effect on the indicators related to oxidative stress. The optimum concentration of CAT was 400 U · m L-1, the survival rate was increased by 33.49%, and the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) was significantly decreased and the content of ascorbic acid (As A) was increased. The introduction of different concentrations of As A in pre-culture, loading, PVS2 treatment and de-loading could increase the post-thaw survival rate of PLBs, and the best effect was achieved at the time of loading. The optimal concentration was 0.1 mmol·L-1 and the survival rate was increased 14.34%, significantly reduced the generation rate of superoxide anion (O2 · -) and the content of MDA, increased the activity of SOD. The results showed that the relative increasing effect of three exogenous antioxidants on the survival rate of PLBs after freezing was CAT> As A> SOD.