热带海洋学报

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铵态氮加富对贝克喜盐草光合作用、谷氨酰胺合成酶和氨基酸成分的影响

江志坚1, 2, 3, 4, 5, 6,Chanaka Isuranga Premarathne1, 3,方扬1, 3,林基帧1, 3,吴云超1, 2, 4, 5, 6,刘松林1, 2, 4, 5, 6,黄小平1*, 2, 3, 4, 5, 6   

  1. 1.中国科学院南海海洋研究所,中国科学院热带海洋生物资源与生态重点实验室,广东 广州 510301;

    2.南方海洋科学与工程广东省实验室(广州),广东 广州 511458;

    3.中国科学院大学,北京 100049;

    4.中国科学院南海生态环境工程创新研究院,广东 广州 510301;

    5.三亚中科海洋研究院,海南省热带海洋生物技术重点实验室,海南 三亚 572100;

    6.广东省应用海洋生物学重点实验室,广东 广州 510301

  • 收稿日期:2022-05-26 修回日期:2022-07-16 出版日期:2022-07-21 发布日期:2022-07-21
  • 通讯作者: 黄小平
  • 基金资助:
    海南省重点研发计划项目(ZDYF2021SHFZ254),国家自然科学基金项目(41735029, 41976144, U1901221, 42176158),南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0405),中国科学院南海生态环境工程创新研究院自主部署项目(ISEE2021PY06,ISEE2021ZD03),和广东省应用海洋生物学重点实验室运行经费(2020B1212060058)

Effects of ammonium enrichment on the photosynthesis, glutamine synthetase and amino acid composition of seagrass Halophila beccarii Asch

JIANG Zhijian1, 2, 3, 4, 5, 6, PREMARATHNE Chanaka Isuranga1, 3, FANG Yang1, 3, LIN Jizhen1, 3, WU Yunchao1, 2, 4, 5, 6, LIU Songlin1, 2, 4, 5, 6, HUANG Xiaoping1*, 2, 3, 4, 5, 6   

  1. 1. Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;

    2. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China;

    3. University of Chinese Academy of Sciences, Beijing 100049, China;

    4. Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China;

    5. Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, CAS, Sanya 572100, China.

    6. Guangdong Provincial Key Laboratory of Applied Marine Biology, Guangzhou 510301, PR China

  • Received:2022-05-26 Revised:2022-07-16 Online:2022-07-21 Published:2022-07-21
  • Contact: Xiao-Ping
  • Supported by:

     The Key Research and Development Project of Hainan Province (ZDYF2021SHFZ254), National Natural Science Foundation of China (41730529, 41976144, U1901221, 42176158), Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0405), the Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences (ISEE2021PY06, ISEE2021ZD03), and the Science and Technology Planning Project of Guangdong Province, China (2020B1212060058).

摘要: 海草贝克喜盐草(Halophila beccarii)由于体型小,其重要性一直被忽视,且近海氮负荷增加导致其处于加速退化状态。目前贝克喜盐草对铵毒害的生理响应尚不清楚。基于室内模拟实验,设置了四种铵态氮梯度(对照、25 μmol?L-1、50 μmol?L-1和100 μmol?L-1),结合叶绿素荧光技术、非损伤微测技术和靶向代谢组学,探讨了铵态氮加富对贝克喜盐草光合作用、叶绿素、叶肉细胞铵离子流速、谷氨酰胺合成酶活性以及营养成分的影响。结果表明,贝克喜盐草叶片的最大相对电子传递速率呈现低铵态氮加富>中铵态氮加富>对照>高铵态氮加富的变化趋势,高铵态氮加富显著降低了最大相对电子传递速率和光能利用效率,进而减少碳库用于铵态氮的同化。同时,铵态氮加富显著增加了铵离子内流流速和谷氨酰胺合成酶活性,把过多的铵同化成氨基酸。但是,铵态氮加富却降低了氨基酸成分,这可能是由于氨基酸被用来合成有机物如关键次生代谢物,以进一步调节和适应铵毒害作用。因此,适度的铵营养盐增加可促进贝克喜盐草的光合作用和生长,而高浓度的铵营养盐则对贝克喜盐草产生毒害作用。

关键词: 铵态氮, 贝克喜盐草, 光合作用, 谷氨酰胺合成酶, 氨基酸

Abstract: Seagrass Halophila beccarii Asch has been neglected due to its small size, and coastal nitrogen loading accelerated its degradation. The physiological response of H. beccarii to ammonium toxicity is not clear. Based on the lab cultivation experiment, the effects of ammonium enrichment in four gradients (Control, 25 μmol?L-1, 50 μmol?L-1 and 100 μmol?L-1) on the photosynthesis, chlorophyll, ammonium ion flux in mesophyll cell, glutamine synthetase activity and nutrients of H. beccarii were studied using chlorophyll fluorescence, non-invasive micro measurement technology and targeted metabolomics. The results showed that the maximum relative electron transport rate exhibited a trend of low ammonium enrichment> moderate ammonium enrichment> control> high ammonium enrichment. High ammonium enrichment significantly reduced the maximum relative electron transport rate and light utilization efficiency, decreasing the carbon pool for ammonium assimilation. Meanwhile, ammonium enrichment significantly enhanced the ammonium ion flux and glutamine synthetase activity, assimilating excess ammonium into amino acids. However, ammonium enrichment reduced the amino acid contents, which might be caused by that amino acids were used to synthesize organic substances such as key secondary metabolites to further regulate and adapt to ammonium toxicity. Therefore, moderate ammonium enrichment was beneficial for the photosynthesis and growth of H. beccarii, while high ammonium enrichment had toxic effect on H. beccarii.

Key words: ammonium, Halophila beccarii Asch, photosynthesis, glutamine synthetase, amino acid