外源一氧化氮对镉胁迫酸枣幼苗生理代谢指标的影响

Effects of Exogenous Nitric Oxide on Physiological Metabolism Indexes of Zizyphus jujube Seedlings Under Cadmium Stress

  • 摘要: 为了解外源一氧化氮对镉胁迫下酸枣幼苗主要外观形态和生理代谢指标的影响,采用水培方法,研究不同硝普钠浓度及一氧化氮消除剂、NaNOx和亚铁氰化钠对镉害胁迫下酸枣叶片和根系的生长、光合特性、活性氧代谢及对矿质营养元素含量的影响。结果表明:镉胁迫对酸枣幼苗生长势产生抑制作用,不同浓度一氧化氮能促进镉胁迫下酸枣幼苗叶长、叶宽、株高、基径和生物量的增加,提高叶片净光合速率、气孔导度、蒸腾速率,叶片和根系内超氧化物歧化酶、过氧化氢酶、抗坏血酸氧化酶和叶片中过氧化物酶活性及脯氨酸含量,降低胞间二氧化碳浓度、根系内过氧化物酶活性、叶片和根系内丙二醛、活性氧水平和镉富集量。同时,外施一氧化氮能使叶片和根系内质膜质子泵和钙泵活性恢复到正常水平,提高植株矿质元素的含量。100 μmol/L硝普钠缓解胁迫效果最好,一氧化氮消除剂、NaNOx和亚铁氰化钠没有起到相同作用,因此缓解反应具有一氧化氮特异性。

     

    Abstract: In order to understand the effects of exogenous nitric oxide on the main appearance and physiological metabolic indexes of Zizyphus jujube seedlings under cadmium stress, hydroponic method was used to study the effects of different concentrations of sodium nitroprusside, nitric oxide scavenger, NaNOx and sodium ferrous cyanide on the growth, photosynthetic characteristics, active oxygen metabolism and mineral nutrient contents of Z.jujube were studied under cadmium stress. The results show that cadmium stress inhibits the growth potential of Z.jujube seedlings. Different concentrations of nitric oxide could promote the increase of leaf length, leaf width, plant height, basal diameter and biomass of Z.jujube seedlings under cadmium stress, and increase the net photosynthetic rate and stomata of leaves, tomatal conductance, transpiration rate, superoxide dismutase, catalase, ascorbic acid oxidase, peroxidase activity and proline content in leaves and roots, and decrease concentration of intercellular carbon dioxide, the activity of peroxidase in roots, MDA in leaves and roots, the level of reactive oxygen species and the accumulation of cadmium. At the same time, exogenous application of nitric oxide could restore the activity of proton pump and calcium pump of plasma membrane to normal level, and increase the content of mineral elements in plant. 100 μmol/L sodium nitroprusside has the best effect on relieving stress. NaNOx and sodium ferrocyanide do not play the same role, so the remission reaction is nitric oxide specific.

     

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