外源NO和H_2O_2对镉胁迫下蚕豆种子萌发及幼苗生长的保护效应

Protective Effects of NO and H_2O_2 on Seed Germination and Seedling Growth of Horsebean under Cd Stress

[目的]探讨NO、H2O2在调控镉胁迫下蚕豆的生理生化机理。[方法]采用水培方法,研究了硝普钠(SNP,作为外源NO供体)、双氧水(H2O2)及其体积比例组合(1∶1)浸泡处理对镉胁迫下蚕豆种子活力的影响;并采用土培方法,研究了上述3种处理对镉胁迫下蚕豆幼苗氧化损伤的保护效应。[结果]与SNP和H2O2单独处理相比,二者互作处理可显著增强镉胁迫下蚕豆种子活力,从而缓解了重金属镉对蚕豆种子萌发的毒害作用;并且SNP和H2O2互作处理对缓解镉胁迫下蚕豆幼苗的氧化损伤存在正协同效应,主要表现在增强了根系活力,提高了叶绿素含量和脯氨酸含量,并降低了MDA含量(P<0.05)。[结论]NO和H2O2的互作处理更有效地减弱了叶绿素的降解反应,提高了叶片细胞的渗透调节能力和耐毒能力。

[Objective] The aim was to discuss the physiological and biochemical mechanism of NO and H2O2 on horsebean under Cd stress.[Method] The solution culture was used to research the effect of soaking treatment with sodium nitopresside（SNP,as NO donor）,hydrogen peroxide（H2O2） and their combination（with volume ratio of 1∶1） on seed vigor of horsebean under Cd stress and the soil culture was used to research the protective effects of above 3 treatments on oxidative damage of horsebean seedlings under Cd stress.[Result] Compared with single treatment of SNP and H2O2,their combined interaction treatment could increase the seed vigor of horsebean under Cd stress remarkably so as to relieve the toxicity effect of heavy metal Cd on seed germination of horsebean and the interaction treatment of SNP and H2O2 had positive cooperative effect on relieving the oxidative damage of horsebean seedlings under Cd stress,which showed to enhance the vigor of root,increase the chlorophyll content and proline content and decrease the MDA content（P〈0.05）.[Conclusion] The interaction treatment of NO and H2O2 could weaken the degradation reaction of chlorophyll effectively and enhance the osmotic adjustment ability and toxic tolerant ability of leaf cells.