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植物研究 ›› 2016, Vol. 36 ›› Issue (3): 427-433.doi: 10.7525/j.issn.1673-5102.2016.03.017

• 研究报告 • 上一篇    下一篇

外源H2O2对混合盐碱胁迫下燕麦幼苗叶片脯氨酸积累和代谢途径的影响

刘建新, 王金成, 刘秀丽, 王风琴   

  1. 1. 陇东学院生命科学与技术学院, 庆阳 745000;
    2. 甘肃省高校陇东生物资源保护与利用省级重点实验室, 庆阳 745000
  • 收稿日期:2015-12-08 出版日期:2016-05-15 发布日期:2016-05-20
  • 作者简介:刘建新(1964-),男,教授,主要从事植物逆境生理研究。
  • 基金资助:
    甘肃省庆阳市科技计划项目(KZ2014-19)资助

Effect of Exogenous H2O2 on Proline Accumulation and Metabolic Pathway in Leaves of Oat Seedlings under Complex Saline-Alkali Stress

LIU Jian-Xin, WANG Jin-Cheng, LIU Xiu-Li, WANG Feng-Qin   

  1. 1. College of Life Science and Technology, Longdong University, Qingyang 745000;
    2. University Provincial Key Laboratory for Protection and Utilization of Longdong Bio-resources in Gansu Province, Qingyang 745000
  • Received:2015-12-08 Online:2016-05-15 Published:2016-05-20
  • Supported by:
    The project was financially supported by the science and technology plan project of Qingyang city in Gansu province(KZ2014-19)

摘要: 为探讨H2O2对盐碱胁迫下植物脯氨酸代谢的调控机理,以燕麦新品种‘定莜6号'幼苗为材料,采用水培法研究了外源H2O2对混合盐碱胁迫下燕麦脯氨酸积累和代谢途径的影响。结果表明,75mmol·L-1混合盐碱(NaCl:Na2SO4:NaHCO3:Na2CO3=12:8:9:1)胁迫可促进燕麦幼苗叶片脯氨酸的积累,提高脯氨酸合成的鸟氨酸途径关键酶鸟氨酸δ-氨基转移酶(δ-OAT)活性,抑制脯氨酸合成的谷氨酸途径关键酶Δ1-吡咯啉-5-羧酸合成酶(P5CS)及脯氨酸降解限速酶脯氨酸脱氢酶(ProDH)活性。在75mmol·L-1混合盐碱胁迫下添加0.01~1000μmol·L-1H2O2可显著提高燕麦幼苗叶片的脯氨酸含量,其中10μmol·L-1H2O2的作用最明显;10μmol·L-1H2O2上调了75mmol·L-1混合盐碱胁迫下燕麦幼苗叶片的P5CS和δ-OAT活性,降低了ProDH活性。此外,10μmol·L-1H2O2使75mmol·L-1混合盐碱胁迫下燕麦幼苗叶片内源性H2O2含量急剧升高后迅速降低。表明外源H2O2能够提高混合盐碱胁迫下燕麦幼苗内源H2O2的含量,并通过活化脯氨酸合成的谷氨酸途径和鸟氨酸途径,抑制脯氨酸的降解,促进混合盐碱胁迫下燕麦幼苗脯氨酸的积累。

关键词: 燕麦, 混合盐碱胁迫, 过氧化氢, 脯氨酸代谢

Abstract: Saline-alkali stress interferes with cell metabolism, and inhibits plant growth and development. Proline metabolism is closely related with plant salt-alkali resistance. As signaling molecules, hydrogen peroxide(H2O2) plays vital roles in the regulation of plant cell metabolism, as well as in adaptation to the environmental stress. In order to understand the regulatory mechanism of exogenous H2O2 on proline metabolism in oat(Avena nuda) under salinity-alkalinity stresses, the ‘Dingyou No.6'(a new oat cultivar) seedlings with two leaves were used to investigate the effects of exogenous H2O2 on proline accumulation in leaves of the seedlings under complex saline-alkali stress by the method of solution culture. The results showed that 75 mmol·L-1 complex saline-alkali stress(molar ratio of NaCl:Na2SO4:NaHCO3:Na2CO3=12:8:9:1) led to a significant accumulation of proline in leaves, and induced a rapid increase of activities of the key enzymes ornithine-δ-aminotransferase(δ-OAT) of proline biosynthesis, and a decrease of activities of the key enzymes Δ1-pyrroline-5-carboxylate synthetase(P5CS) of proline biosynthesis, as well as the key enzyme proline dehydrogenase(ProDH) of proline degradation. Moreover, treatments with 0.01-1 000 μmol·L-1, especially, 10 μmol·L-1 H2O2 could enhance the accumulation of proline in oat seedling leaves under complex saline-alkali stress. H2O2 of 10 μmol·L-1 also increased the activities of P5CS and δ-OAT, and decreased the activity of ProDH in leaves under complex saline-alkali stress. In addition, 10 μmol·L-1 H2O2 treatments could rapidly increase the endogenous H2O2 levels in oat seedling leaves under complex saline-alkali stress. The exogenous H2O2 treatment resulted in the increase of endogenous H2O2 content in oat seedlings under complex saline-alkali stress. H2O2 induced proline accumulation might be a combined result of the activation of glutamate and ornithine pathways of proline biosynthesis and inhibition of proline degradation pathway.

Key words: oat, complex saline-alkali stress, hydrogen peroxide, proline metabolism

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