外源亚精胺对渍涝胁迫下芝麻幼苗根系生理特性的影响

Effects of Exogenous Spermidine on Root Physiological Property of Sesame Seedling under Waterlogging Stress

为探讨缓解芝麻生产过程中渍涝伤害的方法,利用室内水培的方法,研究了不同浓度外源亚精胺（Spd）对渍涝胁迫下芝麻幼苗根系生长及其生理特性的影响.结果显示,渍涝胁迫7 d 后,芝麻幼苗主根长和根系活力分别显著降低2 4 . 3 % 和4 1 . 1 % ;可溶性蛋白、可溶性糖、脯氨酸、M D A 含量和超氧阴离子产生速率分别升高12. 2 % 、14. 2 % 、18. 7 % 、72. 6 % 和66. 9 % ;超氧化物歧化酶（SOD） 、过氧化物酶（POD）、过氧化氢酶（CAT） 活性也分别显著增加了 10. 2 % 、11.4 % 、5. 7 % .外施0.3 - 1.5 mmol/L Spd后,芝麻幼苗主根长、根系活力分别增加3 . 6 % - 1 9 . 6 % 、5. 6 % - 2 8 . 5 % ,可溶性蛋白、可溶性糖、脯氨酸含量分别增加1 0 . 0 % - 45. 7 % 、8. 4 % - 42. 9 % 、8. 4 % - 3 2 . 0 % ,S0 D、P0 D、CAT 活性分别提高 7 . 0 % - 4 1 . 4 % 、5 . 1 % - 5 3 . 9 % 、1 3 . 9 % - 5 5 . 6 % , MDA 含量和超氧阴离子产生速率分别降低8 . 6 % - 2 3 . 8 % 、3.2 % - 2 1 . 7 % .可见,不同浓度外源S pd均能够有效提高渍涝胁迫下芝麻幼苗根系活力、渗透调节能力及抗氧化酶活性,减轻膜脂过氧化程度,缓解渍涝胁迫所造成的伤害,提高芝麻幼苗抗涝能力,其中以1.2 mmol/L Spd效果最好.

Hydroponics experiments were carried out to study the effects of exogenous spermidine( Spd)with different concentrations( 0. 3,0. 6,0. 9,1. 2,1. 5 mmol / L) on the root growth and physiological characteristics of sesame seedlings under waterlogging stress,so as to explore the method of alleviating damages by waterlogging in the process of sesame production. The results showed that,after waterlogging stress for 7 d,the main root length and root activity significantly decreased by 24. 3% and 41. 1%; the contents of soluble protein,soluble sugar,proline,MDA and super oxygen anion producing rate increased by 12. 2%,14. 2%,18. 7%,72. 6% and 66. 9%,and the activities of superoxide dismutase( SOD),peroxidase( POD) and catelase( CAT) significantly increased by 10. 2%,11. 4%,5. 7%. While exogenous Spd( 0. 3—1. 5 mmol / L) promoted rootstock growth,increased the root activity by 3. 6% —19. 6%,5. 6% —28. 5%,improved the contents of soluble protein,soluble sugar,proline and the activities of SOD,POD,CAT by 10. 0% —45. 7%,8. 4% —42. 9%,8. 4% —32. 0%,7. 0% —41. 4%,5. 1% —53. 9%,13. 9% —55. 6% respectively,decreased the MDA content and super oxygen anion producing rate by8. 6% —23. 8% and 3. 2% —21. 7%. The results suggested that different concentrations of exogenous Spd could enhance root activity,osmotic adjustment ability and antioxidant enzymes activities,reduce the degree of membrane lipid peroxidation,alleviate the damages by waterlogging,and improve waterlogging tolerance of sesame seedlings,1. 2 mmol / L Spd was optimal.