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草业学报 ›› 2023, Vol. 32 ›› Issue (7): 206-215.DOI: 10.11686/cyxb2022340

• 研究论文 • 上一篇    

外源褪黑素缓解甜高粱幼苗干旱胁迫的生理效应

梁佳1,2(), 胡朝阳3, 谢志明1,2, 马刘峰1,2, 陈芸1,2, 方志刚1,2()   

  1. 1.喀什大学生命与地理科学学院,新疆 喀什 844006
    2.新疆帕米尔高原生物资源与生态重点实验室,新疆 喀什 844006
    3.江西农业大学生物科学与生物工程学院,江西 南昌 330045
  • 收稿日期:2022-08-26 修回日期:2022-10-20 出版日期:2023-07-20 发布日期:2023-05-26
  • 通讯作者: 方志刚
  • 作者简介:E-mail: fangyi20@126.com
    梁佳(1994-),女,四川遂宁人,硕士。E-mail: ljia0920@126.com
  • 基金资助:
    新疆维吾尔自治区高校科研计划自然科学项目(XJEDU2019Y038);新疆维吾尔自治区面上项目(2022D010A232)

Exogenous melatonin alleviates the physiological effects of drought stress in sweet sorghum seedlings

Jia LIANG1,2(), Zhao-yang HU3, Zhi-ming XIE1,2, Liu-feng MA1,2, Yun CHEN1,2, Zhi-gang FANG1,2()   

  1. 1.College of Life and Geographic Sciences,Kashi University,Kashi 844006,China
    2.Xinjiang Key Laboratory of Biological Resources and Ecology of Pamir Plateau,Kashi 844006,China
    3.College of Bioscience and Bioengineering,Jiangxi Agricultural University,Nanchang 330045,China
  • Received:2022-08-26 Revised:2022-10-20 Online:2023-07-20 Published:2023-05-26
  • Contact: Zhi-gang FANG

摘要:

为探究外源褪黑素缓解甜高粱幼苗干旱胁迫可能的生理机制,以甜高粱品种‘大力士’为材料,采用盆栽试验方法,分析自然干旱条件下,叶面喷施褪黑素(100 μmol·L-1)对甜高粱幼苗生长及生理特性的影响。结果表明,干旱胁迫导致植株地上部水分失衡,叶绿体结构受损,细胞产生氧化胁迫,显著抑制甜高粱幼苗的生长。喷施褪黑素可显著降低甜高粱叶片丙二醛(MDA)含量,积累更多的可溶性蛋白和脯氨酸,提高叶片含水量,使叶绿体基粒片层排列有序,光合色素含量升高;喷施褪黑素还能显著提高叶片过氧化物酶(POD)和硝酸还原酶活性。综合上述,喷施100 μmol·L-1褪黑素能进一步激发干旱环境中甜高粱叶片抗氧化系统的保护作用,通过渗透调节,维持植株水分平衡,改善叶绿体结构,提高光合色素含量,协同增强氮代谢,促进植株生长,从而缓解干旱对甜高粱幼苗的伤害。

关键词: 甜高粱, 干旱胁迫, 褪黑素, 生理机制

Abstract:

In order to explore the possible physiological mechanism of exogenous melatonin alleviation of drought stress in sweet sorghum seedlings, a pot experiment was set up to investigate the effects of spraying melatonin (100 μmol·L-1) on the growth and physiological characteristics of ‘Dalish’ sweet sorghum seedlings under natural drought conditions. It was found that drought stress resulted in water imbalance in plant shoots, damaged the chloroplast structure and produced intracellular oxidative stress, which significantly inhibited the growth of the sweet sorghum seedlings. Spraying 100 μmol·L-1 melatonin significantly reduced the malondialdehyde content in leaves, facilitated increased accumulation of soluble protein and proline, increased the water content of leaves, promoted orderly arrangement of the granula lamellae of chloroplast, and increased the content of photosynthetic pigment. Spraying melatonin also significantly increased the activities of peroxidase and nitrate reductase in leaves. In conclusion, spraying 100 μmol·L-1 melatonin enhanced the protective effect of antioxidant systems in sweet sorghum leaves under drought conditions, which helped to maintain plant water balance, improve chloroplast structure and increase the photosynthetic pigment content through osmotic regulation and synergistically enhanced nitrogen metabolism. At the same time, exogenous melatonin enhanced nitrogen metabolism and promoted the plant growth, resulting in alleviation of drought damage to sweet sorghum seedlings.

Key words: sweet sorghum, drought stress, melatonin, physiological mechanism