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以野生草地早熟禾(Poa pratensis)和硬质早熟禾(Poa sphondylodes)为材料,通过人工室内模拟低温逆境胁迫,研究外源一氧化氮(NO)供体亚硝基铁氰化钠(硝普钠,SNP)对低温胁迫下野生早熟禾幼苗生长、渗透调节和抗氧化系统的影响,探讨外源NO提高早熟禾抗寒性的生理机制。结果表明,低温胁迫下:0~700μmol·L-1浓度范围内,随SNP浓度的增大,两个供试材料的地上生物量和生长速度先增大后减小,相对膜透性、丙二醛(MDA)含量、游离脯氨酸(F-Pro)含量先减小后增大,可溶性糖(SS)和可溶性蛋白(SP)含量先增加后减小,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性先增强后减弱;高浓度NO产生伤害,低浓度NO则有保护作用;SNP浓度100μmol·L-1时,膜脂过氧化水平最低,渗透调节物质积累最多,保护酶活性最强,对低温胁迫的缓解效果最佳。硬质早熟禾对低温胁迫下外源NO的缓解较草地早熟禾敏感。
In the present study, Poa pratensis and Poa sphondylodes were used to study the effects of exogenous nitric oxide (NO) donor nitroso-sodium cyanide Sodium, SNP) on the growth, osmotic adjustment and antioxidant system of P. solani seedlings under low temperature stress, and to explore the physiological mechanism of the exogenous NO in improving the cold resistance of Kentucky bluegrass. The results showed that the aboveground biomass and growth rate of two tested materials increased first and then decreased with the increasing of SNP concentration under the condition of 0 ~ 700μmol·L-1, the relative membrane permeability, The contents of MDA and F-Pro first decreased and then increased, while the content of soluble sugar (SS) and soluble protein (SP) increased at first and then decreased. The content of superoxide dismutase (SOD) (POD) and catalase (CAT) increased first and then decreased; high concentration of NO produced injury, while low concentration of NO had protective effect. When the concentration of SNP was 100μmol·L-1, the level of membrane lipid peroxidation The lowest, osmotic adjustment material accumulation, protective enzyme activity strongest, to alleviate the effect of low temperature stress best. Hard bluegrass was more sensitive to exogenous NO under cold stress than that of Kentucky bluegrass.