外源NO对NaCl胁迫下辣椒幼苗氧化损伤的保护效应

以辣椒品种陇椒2号为试验材料,研究了外源NO供体硝普钠(SNP)对辣椒幼苗氧化损伤的影响.结果显示,在100 mmol/L NaCl胁迫下,辣椒叶片的MDA含量、质膜相对透性和脯氨酸含量均增加,保护酶SOD、CAT活性降低,而POD活性只在胁迫18 d时降低.0.1 mmol/L SNP处理可减缓NaCl胁迫下辣椒幼苗叶片MDA含量的上升,降低叶片质膜相对透性,并诱导SOD、POD和CAT活性增加,提高脯氨酸含量,表明外源NO可以通过提高盐胁迫下辣椒幼苗叶片组织的抗氧化能力来缓解氧化损伤.而SNP相似物NaNO2和K3Fe(CN)6处理对盐胁迫引起的氧化损伤并没有起到明显的缓解作用,进一步证实了NO对辣椒幼苗耐盐性具有专一性的调节作用.

Protective Effects of Exogenous Nitric Oxide on Oxidative Damage in Pepper Seedlings under NaCl Stress

A pepper variety,'Longjiao 2' was employed to study the effect of sodium nitropprusside(SNP,an exogenous nitric oxide donor) on oxidative damage in pepper seedlings under 100 mmol/L NaCl stress.The results showed that NaCl stress could cause the pepper-seedling leaves to increase their membrane relative permeability,malondialdehyde(MDA) and proline contents,and reduce their protective enzymes(SOD,POD) activities,the activity of POD was decreased only when 18 d treatment.0.1 mmol/L SNP could alleviate the accumulation of MDA and decrease membrane relative permeability in leaves of pepper seedlings under salt stress.Meanwhile,the activities of protective enzymes(including SOD,POD and CAT) and content of proline in leaves of pepper seedlings were increased under salt stress.The above results indicated that exogenous nitric oxide could alleviate the oxidative damage caused by salt stress,which was mainly achieved by means of enhancing anti-oxidative capability in pepper seedlings.Furthermore,NaNO2 and K3Fe(CN)6 treatments couldn't significantly alleviate the oxidative damage caused by salt stress,consequently further confirmed the specific role of NO regulating the salt tolerance of pepper seedlings.