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基于我国酸雨类型正逐渐从硫酸型趋向硝酸型转化,分别以含有较多硫酸根的硫酸、硝酸混合液(Sulphurrich acid,SRA)和较多硝酸根的硫酸、硝酸混合液(Nitric-rich acid,NRA)浸泡离体油橄榄叶片,模拟硫酸型、硝酸型两种类型的酸胁迫,探讨不同酸度不同胁迫时间油橄榄离体叶片抗性生理的差异及其变化机理.结果表明,随着胁迫时间延长,叶片丙二醛(MDA)含量显著增加(P<0.05),叶绿素和类胡萝卜素含量降低,可溶性糖含量先增后减,脯氨酸含量和细胞膜稳定指数(MSI)下降;对比这两种类型的酸胁迫,p H为3的酸胁迫48 h时NRA酸胁迫叶绿素含量较SRA酸胁迫低10.12%(以硝酸型相关数据为基数,下同),类胡萝卜素含量、MSI下降幅度及MDA含量升高幅度均大于SRA型酸胁迫,说明NRA型酸胁迫造成了较为严重的色素分解、脂质过氧化和细胞膜损伤.酸胁迫还引起超氧阴离子产生速率和过氧化氢含量增加,且硝酸型酸胁迫活性氧水平升高较大;抗氧化酶活性先变大后变小,维生素C含量和还原型谷胱甘肽含量均减小,且NRA酸胁迫减小幅度大于SRA,说明NRA酸胁迫比SRA酸胁迫对油橄榄叶片具有较强的氧化性,对抗氧化酶、类胡萝卜素、还原型谷胱甘肽等构成的细胞膜保护系统损害更大,从而加重了细胞膜的损伤,如p H为3的酸胁迫48 h时,NRA酸胁迫MSI较SRA酸胁迫低26.52%.可见,在较强的酸溶液(p H 3.0)胁迫较长时间时,硝酸型酸胁迫相对于硫酸型酸胁迫对细胞内的抗氧化系统具有较强的破坏,并由此造成了较为严重的细胞膜损伤.
Based on the type of acid rain in our country, the type of acid rain is gradually transformed from sulfuric acid type to nitric acid type. Sulphurrich acid (SRA) and nitric acid (Nitric-rich acid) NRA) were used to study the effects of different acidity and stress on the resistance physiology of detached leaves of Olea europaea.The results showed that with the prolongation of stress time, (P <0.05), the content of chlorophyll and carotenoid decreased, soluble sugar content increased first and then decreased, proline content and cell membrane stability index (MSI) decreased; compared with the two types , The chlorophyll content of NRA acid stress was 10.12% lower than that of SRA under acid stress of pH 3 for 48 h (based on the correlation data of nitrate type, the same below), the decrease of carotenoid content and the content of MDA Increase more than SRA type acid stress, indicating that NRA-type acid stress caused more serious pigment decomposition, lipid peroxidation and cell membrane damage.Acid stress also caused superoxide anion generation rate and hydrogen peroxide content And the level of reactive oxygen species of nitric acid increased significantly. The activity of antioxidant enzymes first increased and then decreased, the contents of vitamin C and reduced glutathione decreased, and the decrease of NRA acid stress was larger than that of SRA , Indicating that acid stress of NRA is more oxidative than that of SRA acid stress on the leaves of P. olives and the damage to the cell membrane protection system composed of antioxidant enzymes, carotenoids and reduced glutathione is more serious, When the acid stress of pH 3 was 48 h, the MSI of NRA acid stress was 26.52% lower than that of SRA acid treatment. It can be seen that under the condition of strong acid solution (p H 3.0) for a long time, Acid stress has a strong destructive effect on the intracellular antioxidant system, resulting in a more serious cell membrane damage.