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为探讨一氧化氮(nitric oxide,NO)对紫外线-B(UV-B)辐射胁迫下植物抗氧化系统的影响,以盆栽5年生南方红豆杉(Taxus chinensis var.mairei)幼苗为材料,硝普钠(sodi-um nitroprusside,SNP)为外源NO供体,设置CK(对照)、SNP(+0.1mmol·L-1SNP)、UV-B(+4.22kJ·m-2·d-1UV-B)及UV-B+SNP(+0.1mmol·L-1SNP+4.22kJ·m-2·d-1UV-B)4个处理,研究外源NO对UV-B胁迫下南方红豆杉幼苗针叶过氧化氢(H2O2)含量、脂质过氧化程度及抗氧化物质含量的影响。结果表明:UV-B胁迫显著提高了南方红豆杉针叶H2O2及MDA含量(P<0.05),施加外源NO降低UV-B胁迫下针叶H2O2及MDA含量,提高紫杉醇、类黄酮及类胡萝卜素等抗氧化物质含量(P<0.05);各处理对抗氧化酶活性影响不同,SNP处理显著提高针叶中CAT和POD活性(P<0.05),UV-B和SNP+UV-B处理均提高针叶中POD活性,降低CAT活性和APX活性(P<0.05)。本研究证实,外源NO可提高UV-B胁迫下植物抗氧化酶活性和抗氧化物质含量,降低其H2O2含量及脂质过氧化程度,从而在一定程度上缓解UV-B胁迫对植物的伤害。
In order to investigate the effect of nitric oxide (NO) on the antioxidant system of plants under UV-B radiation stress, five-year-old potted Taxus chinensis var. Mairei seedlings were used as materials, Sodio-um nitroprusside (SNP) was an exogenous NO donor, and CK (control), SNP (+0.1 mmol·L-1 SNP) and UV-B (+4.22 kJ · m-2 · d-1UV-B ) And UV-B + SNP (+0.1 mmol·L-1 SNP + 4.22 kJ · m-2 · d-1 UV-B) were used to study the effects of exogenous NO on conifers Hydrogen peroxide (H2O2) content, lipid peroxidation and antioxidants content. The results showed that the UV-B stress significantly increased the content of H2O2 and MDA (P <0.05), the content of H2O2 and MDA in needle needles under UV-B stress and the increase of paclitaxel, flavonoids and carrot (P <0.05). The activities of antioxidant enzymes in different treatments were different. The activities of CAT and POD were significantly increased in SNP treatment (P <0.05), and both of UV-B and SNP + UV-B treatment were increased POD activity in coniferous leaves decreased CAT activity and APX activity (P <0.05). This study confirmed that exogenous NO could enhance the antioxidant enzyme activity and antioxidants content of plants under UV-B stress, reduce the content of H2O2 and the degree of lipid peroxidation, and thus to some extent alleviate the damage to plants caused by UV-B stress .