欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2021, Vol. 30 ›› Issue (4): 160-169.DOI: 10.11686/cyxb2020173

• 研究论文 • 上一篇    下一篇

PEG胁迫下紫花苜蓿幼苗内源激素对NO的响应

张小芳1,2,3(), 魏小红1,2,3(), 刘放1, 朱雪妹1   

  1. 1.甘肃农业大学生命科学技术学院,甘肃 兰州 730070
    2.甘肃省作物遗传改良与种质创新重点实验室,甘肃 兰州 730070
    3.甘肃省干旱生境作物学重点实验室,甘肃 兰州 730070
  • 收稿日期:2020-04-13 修回日期:2020-07-13 出版日期:2021-04-20 发布日期:2021-03-16
  • 通讯作者: 魏小红
  • 作者简介:Corresponding author. E-mail: weixh@gsau.edu.cn
    张小芳(1993-),女,甘肃庆阳人,在读硕士。E-mail: 2693287798@qq.com
  • 基金资助:
    国家自然基金项目(31560663)

Endogenous hormone responses to nitric oxide in alfalfa seedlings under PEG stress

Xiao-fang ZHANG1,2,3(), Xiao-hong WEI1,2,3(), Fang LIU1, Xue-mei ZHU1   

  1. 1.College of Life Science and Technology,Gansu Agricultural University,Lanzhou 730070,China
    2.Gansu Key Lab of Crop Improvement and Germplasm Enhancement,Lanzhou 730070,China
    3.Gansu Provincial Key Laboratory of Aridland Crop Science,Lanzhou 730070,China
  • Received:2020-04-13 Revised:2020-07-13 Online:2021-04-20 Published:2021-03-16
  • Contact: Xiao-hong WEI

摘要:

以紫花苜蓿幼苗为材料,采用聚乙二醇(PEG-6000)为渗透调节物质模拟干旱胁迫,通过外源喷施NO释放剂硝普钠(SNP)和清除剂(cPTIO),用液相色谱/质谱联用(LC/MS)法分析研究PEG胁迫下紫花苜蓿幼苗叶片和根系中4种内源激素脱落酸(ABA)、生长素(IAA)、水杨酸(SA)和赤霉素(GA3)对NO的响应。结果表明:1)PEG胁迫下施加外源NO能促进紫花苜蓿叶片和根中NO含量的增加,其清除剂明显降低了紫花苜蓿叶片中NO含量;2)随着处理时间的延长,叶片和根中的ABA和SA含量逐渐增加,而根系中ABA和SA含量的增加较叶片晚。在胁迫第8天,叶中外源NO处理的ABA含量比SA含量高6.68倍,而喷施NO清除剂的ABA含量比SA含量高77.22%,并且叶中外源NO处理的ABA含量明显高于根中;3)NO会在短期内诱导叶片和根系中IAA和GA3含量增加,在胁迫的第4天,叶片中外源NO处理的IAA含量高于其清除剂1.65倍,而根中喷施NO清除剂的IAA含量比NO处理高8.70%;叶片和根中NO处理的GA3含量在第2天达到最大值后降低,比喷施NO清除剂的GA3含量分别高54.49%和84.65%。综上所述,NO可通过诱导紫花苜蓿IAA、ABA、GA3和SA四种激素的代谢水平及根中的相互转化调控植物的生长与抗逆性,尤其是ABA和SA在紫花苜蓿中的调节。

关键词: 紫花苜蓿, PEG胁迫, 一氧化氮, 内源激素

Abstract:

This research studied the endogenous hormone responses to nitric oxide (NO) in leaves and roots of 50-day old alfalfa seedlings under PEG stress. Polyethylene glycol (PEG-6000) was used as the osmotic regulator to simulate drought stress. Exogenous spraying of NO releasing agent sodium nitroprusside (SNP) and NO scavenger carboxy-PTIO (cPTIO), and liquid chromatography/mass spectrometry methods were used to study the response of four endogenous hormones (abscisic acid, ABA; indole-3-acetic acid, IAA; salicylic acid, SA; gibberellin, GA3) to NO in the leaf and root systems of alfalfa seedlings under PEG stress. Treatments included in the experiment were: T1, distilled water (CK), T2, PEG added; T3, SNP+PEG added; and T4, cPTIO+PEG added. It was found that: 1) The application of exogenous NO under PEG stress (T3) can promote the NO content in the leaf and root of alfalfa, and the NO scavenger cPTIO (T4) significantly reduced the NO content in leaves of alfalfa. 2) With increasing duration of PEG stress, the levels of ABA and SA in leaves and roots increased gradually, but the ABA and SA levels in the root system increased later than those in the leaves. On the 8th day of stress, the leaf ABA content in plants of T3 was 6.68 times higher than the SA content, while the ABA content in plants of T4 was 77.22% higher than the SA content, and the leaf ABA content in leaves of T3 plants was significantly higher than that in roots. 3) NO rapidly induces an increase in the IAA and GA3 concentrations in leaves and roots. On the 4th day of stress, the IAA levels in leaves under exogenous NO treatment were 1.65 times higher than in the cPTIO scavenger treatment. Meanwhile the IAA concentration in roots was 8.70% higher in T4 than T3, and the GA3 content in leaves and roots of T3 was 54. 49% and 84. 65% higher, respectively, than in T4. GA3 content reached its maximum on the second day of treatment and decreased thereafter. In summary, NO is here shown to regulate the growth and stress resistance of alfalfa plants by raising or lowering the metabolic levels of IAA, ABA, GA3 and SA, the regulation of ABA and SA in alfalfa is particularly prominent.

Key words: Medicago sativa, PEG stress, nitric oxide, endogenous hormone