外源NO对渗透胁迫下油松种子萌发及幼苗生理特性的作用

Effects of Exogenous Nitric Oxide on Seed Germination and Seedling Physiological Changes of Chinese Pine under Osmotic Stress

利用PEG6000处理的方法,研究了外源NO对渗透胁迫下油松种子萌发及幼苗生理特性的影响。结果表明,渗透胁迫下,油松种子发芽率下降,严重影响种子胚根的生长,低浓度(0.1～0.3mmol.L-1)NO能有效缓解渗透胁迫的影响,促进种子的萌发;高浓度(>0.5mmol.L-1)NO对油松种子萌发有一定的抑制作用。渗透胁迫条件下,外源NO处理能使油松幼苗SOD活性增强,超氧物阴离子自由基(O2-)、H2O2、和丙二醛(MDA)含量降低,脯氨酸及叶绿素含量增加。这在一定程度上表明,外源NO处理可消除活性氧减轻渗透胁迫引起的膜脂过氧化作用,同时通过增加脯氨酸等渗透调节物质增强油松幼苗的抗逆性。

Effects of exogenous nitric oxide （NO） on seed germination and seedling physiological changes of Chinese pine under osmotic stress （treated by PEG6000） were studied. The results showed that Chinese pine seed germination was inhibited under osmotic stress, the germination rate dropped and radical elongation was severely inhibited. Using SNP,we found that low concentration （0.1-0.3 mmol . L-1 ） NO promoted seed germination,while high concentration （more than 0. 5 mmol . L - ） presented inhibition effect. For seedlings,exogenous NO enhanced its SOD activity,increased its proline and chlorophyll contents under osmotic stress, at the same time exogenous NO decreased hydrogen peroxide, superoxide and MDA contents of Chinese pine seedlings. So exogenous NO could improve the drought resistance of Chinese pine seedlings.