外源NO供体硝普钠(SNP)对盐胁迫下紫苏种子萌发及幼苗抗氧化酶活性的影响

Effect of Exogenous Nitric Oxide Donor SNP on Seed Germination and Antioxidase Activities of Perilla frutescens Seedlings Under NaCl Stress

目的:通过对紫苏种子萌发及幼苗生理特性的研究,寻找提高紫苏种子及幼苗在盐胁迫条件下抗盐能力的途径。方法:测定了不同浓度硝普钠(SNP)处理后的NaCl胁迫下紫苏种子的发芽势、发芽率、发芽指数和活力指数,并对紫苏幼苗叶片的丙二醛(MDA)含量、硝酸还原酶(NR)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性进行了测定。结果:结果显示在100 mmol/L的NaCl胁迫下的紫苏种子萌发受到显著抑制,但是经过不同浓度的SNP处理后,萌发指标均有升高,其中经过0.1 mmol/L的SNP处理后,各项指标均达到最大值,发芽势为60.4%,发芽率为78.3%,发芽指数为13.7,活力指数为为0.1093。SNP处理降低了叶片MDA的含量,并且提高了NR、SOD、POD和CAT四种酶的活性,且均为当SNP浓度为0.1 mmol/L时达到最大值,分别为:1.52μg/g.h、0.32 U/mg、5.9 U/mg和4.8 U/mg。结论:0.1 mmol/L的SNP能够有效的减缓NaCl胁迫对紫苏种子及幼苗产生的伤害,提高了种子及幼苗的抗盐能力。

Objective：To explore the method of improving the salt resistance ability of seeds and seedlings of Perilla frutescens under NaCl stress.Methods：Physiological indexes of Perilla frutescens seeds treated by sodium nitroprusside（SNP）under NaCl stress like the germination vigor,germination rate,germination index and vigor index were measured.And other indexes like the activities of nitrate reductase（NR）,malondialdehyde（MDA）,superoxide（SOD）,peroxidase（POD）and catalase（CAT）were also measured.Results： The germination indexes of Perilla frutescens seeds under NaCl stress had obvious inhibition.But after the treatment with different concentrations of SNP,every germination indexes were all increased.And the seeds that treated with SNP with the concentration of 0.1 mmol/L has the most significantly increase in every index.The germination vigor was 60.4%,the germination rate was 78.3%,the germination index and vigor index were 13.7 and 0.1093 respectively.The content of MDA was decreased after the treatment of SNP.The activities of four enzymes included NR,SOD,POD and CAT were increased with the treatment of SNP,and get the maximin（1.52 μg/g·h、0.32 U/mg、5.9 U/mg and 4.8 U/mg respectively）with the concentration of 0.1 mmol/L SNP.Conclusion：SNP with concentration of 0.1 mmol/L could significantly alleviate the damages to the seeds and seedlings of Perilla frutescens under NaCl stress,and promote the salt resistance of the seeds and seedlings.