外源一氧化氮对UV-B胁迫下红松幼苗光合特性和活性氧代谢的影响

The Effects of Exogenous Nitric Oxide on Photosynthetic Characteristics and Active Oxygen Metabolism in Pinus koraiensis Seedlings under UV-B Stress

[目的]研究外源一氧化氮对增强UV-B辐射胁迫后红松幼苗光合特性和活性氧代谢的影响。[方法]设4个组:1CK;2SNP(0.01 mmol/L);3UV-B(4.22 k J/(m2·d));4SNP(0.01 mmol/L)+UV-B(4.22 k J/(m2·d))。分别于处理1、3、5、7、9 d取样,测定各项生理指标。[结果]施加外源NO,显著增加红松幼苗针叶光合色素含量,缓解UV-B对光合作用的破坏;外源NO处理降低UV-B胁迫对红松幼苗针叶细胞膜的膜相对透性的破坏及MDA含量的积累;UV-B处理和SNP+UV-B处理都提高了APX、SOD和POD活性。[结论]植物防卫反应信号分子NO广泛参与红松幼苗对UV-B胁迫的应答与防御。外源NO对红松幼苗由于UV-B辐射引起的氧化损伤有明显的缓解作用。

[ Objective ] To research the influence of photosynthetic characteristics and active oxygen metabolize of Pinus koraiensis Sieb. et Zucc. seedling what was in UV-B stress which had been enhanced by exogenous NO. [ Method] Four groups in this experiment were set up： ① CK; ② SNP （0.01 mmol/L）, ③ UV-B （4.22 kJ/（m^2·d）, ④ SNP （0.01 mmol/L） ＋UV-B（4.22 kJ/（m^2· d）. Then took samples from each group and measured physiological indexes when they had been disposed 1, 3, 5, 7, 9 days. [ Result] Adding exogenous NO had not only significantly increased the photosynthetic pigment content of Pinus koraiensis seedling needles but also reduced damage of UV-B to photosynthesis. Adding exogenous NO reduced damage of UV-B stress to the membrane relatively permeability of Pinus koraiensis seedling nee- dles eytomembrane and accumulation of MDA content. Not only UV-B - dispose but SNP ＋ UV-B - dispose could raise activity of APX, SOD and POD. [ Conclusion] As the plant defense reaction signal molecule, NO partook reply and defense of Pinus koraiensis seedling to UV-B - dispose widely. Exogenous NO could relieve Pinus koraiensis seedling oxidation harm from UV-B radiation evidently.