一氧化氮对UV-B辐射增强条件下燕麦幼苗氧化损伤的缓解作用

以燕麦品种“定燕2号”和“晋燕14号”为研究材料，研究紫外线B（ultraviolet rays-B， UV-B）辐射增强条件下，一氧化氮（nitric oxide， NO）供体硝普钠（sodium nitroprusside， SNP）对燕麦幼苗活性氧含量、膜脂过氧化和抗氧化物质含量的影响。结果表明：NO能够降低UV-B辐射增强条件下“定燕2号”和“晋燕14号”的超氧阴离子（superoxide radical， O₂^·-）产生速率、羟自由基（hydroxyl free radical， OH^·）、过氧化氢（hydrogen peroxide， H₂O₂）和丙二醛（malondialdehyde， MDA）含量。UV-B辐射时间为6 h，施加SNP时，“定燕2号”的超氧化物歧化酶（superoxide dismutase， SOD）活性和过氧化物酶（peroxidase， POD）活性、“晋燕14号”的SOD活性高于其他处理组；UV-B辐射时间为3 h，施加SNP时，“定燕2号”、“晋燕14号”的抗坏血酸过氧化物酶（ascorbate peroxidase， APX）活性显著高于0 h、12 h处理组。UV-B辐射时间为6 h，“定燕2号”的脱氢抗坏血酸（dehydroascorbic acid， DHA）含量显著高于其他处理组；而UV-B辐射时间为0 h，“晋燕14号”的DHA 含量显著高于其他处理组。NO对UV-B辐射增强下“定燕2号”和“晋燕14号”抗氧化性影响的综合测评均为：3 h>6 h>12 h>0 h。本研究结果为NO在燕麦育种、抗氧化机制等提供理论依据。

Nitric oxide alleviates the oxidative damage of oat seedlings under UV-B radiation enhancement

The effects of NO on the content of reactive oxygen, membrane lipid peroxidation and antioxidant substances in oat seedlings under UV-B radiation enhancement were studied using oat varieties Dingyan 2 and Jinyan 14. The results showed that NO reduced the rate of O₂^·- production, content of OH^·, H₂O₂ and MDA in both oat varieties under the condition of UV-B radiation enhancement. The SOD activity and POD activity of Dingyan 2 and SOD activity of Jinyan 14 were higher than those of other treatment groups when the duration of UV-B radiation was 6h and SNP was applied. The APX activity of Dingyan 2 and Jinyan 14 was significantly higher than that of 0h and 12 h when the duration of UV-B radiation was 3 h and SNP was applied. The DHA content of Dingyan 2 was significantly higher than that of other treatment groups when the duration of UV-B radiation was 6 h. The DHA content of Jinyan 14 was significantly higher than that of other treatment groups when the duration of UV-B radiation was 0 h. The comprehensive evaluation of the effect of NO on the antioxidant activity of both Dingyan 2 and Jinyan 14 under UV-B radiation enhancement was as follows: 3 h>6 h>12 h>0 h. The results of this study provide theoretical basis for NO in breeding and antioxidant mechanism.