三种高原常见沉水植物对不同浓度铵氮的生理响应机制研究  

Physiological Response of Three Common Submerged Plateau Plants to Ammonia Nitrogen

作　　者：常诏峰 鲜玲 Samuel Wamburu Muthui 刘帆[3] 严雪 CHANG Zhao-feng;XIAN Ling;Samuel Wamburu Muthui;LIU Fan;YAN Xue(Tibetan Plateau Ecology and Environment Research Center,Tibet University,Lhasa 850000,P.R.China;College of Science,Tibet University,Lhasa 850000,P.R.China;Key Laboratory of Aquatic Botany and Watershed Ecology,Wuhan Botanical Garden,Chinese Academy of Sciences,Wuhan 430074,P.R.China)

机构地区：[1]西藏大学青藏高原生态与环境研究中心,西藏拉萨850000 [2]西藏大学理学院,西藏拉萨850000 [3]中国科学院水生植物与流域生态重点实验室,中国科学院武汉植物园,湖北武汉430074

出　　处：《水生态学杂志》2022年第6期108-115,共8页Journal of Hydroecology

基　　金：国家自然科学基金项目(31270372,32070383)。

摘　　要：分析植物受到高铵态氮胁迫时的响应特征,明确高浓度铵态氮对沉水植物产生毒性机制,为利用沉水植物修复高浓度铵态氮污染水体提供理论指导。选取苦草(Vallisneria natans)、大茨藻(Najas marina)和穿叶眼子菜(Potamogeton perfoliatus)3种沉水植物为研究对象,研究了不同浓度铵态氮(0、0.1、3、15和50 mg/L)对3种沉水植物的生理影响,初步探讨了沉水植物在高铵态氮浓度水体中退化的原因。当水体铵态氮浓度超过15 mg/L时,植物体内叶绿素和蛋白含量呈下降趋势,而游离氨基酸的含量呈上升趋势,植物叶绿素荧光值显著降低,植物无法正常进行光合作用。当铵态氮浓度低于15 mg/L时苦草对铵态氮的去除率明显低于大茨藻和穿叶眼子菜。铵态氮浓度较高时,大茨藻组织总氮含量高于穿叶眼子菜和苦草,而FAA和可溶性蛋白含量则是穿叶眼子菜最高。当水体中铵态氮浓度达到15 mg/L时,湖泊中广泛分布的沉水植物无法存活,植物光合能力下降是影响其存活的主要因素。本研究从机理层面初步揭示了3种广布沉水植物物种在高铵态氮水体中消失的原因。In this study, three submerged plant species(Vallisneria natans, Najas marina and Potamogeton perfoliatus) were selected for a stress test with high concentrations of ammonia nitrogen(NH-N)Four NH-N concentrations with a control(0, 0.1, 3, 15 and 50 mg/L) were set, and the physiological response of the three plants to the different concentrations were compared by determining the levels of NH-N and dissolved oxygen in the solution, and the total nitrogen(TN), free amino acid(FAA),soluble protein, chlorophyll-a and maximum photochemical quantum yield(Fv/Fm) in the plant leaves.The response of submerged plants to high concentrations of NH-N was then characterized and the causes of submerged macrophyte degradation at high NH-N concentrations were discussed. With increasing solution concentrations of NH-N, the removal rate of NH-N by plants decreased. In treatment groups with NH-N below 15 mg/L, the removal rate of NH-N by V. natans was clearly lower than by N. marina and P. perfoliatus. In the treatments with higher NH-N, the TN in V. natans leaves was higher than in the leaves of N. marina and P. perfoliatus, while the levels of FAA and soluble protein were highest in P. perfoliatus leaves. When the concentration of NH-N in the water body exceeded 15 mg/L, the chlorophyll-a and protein in the three plants declined, while the FAA increased.Further, the Fv/Fmof macrophytes decreased significantly, indicating that photosynthesis was inhibited when the NH-N concentration reached 15 mg/L. In conclusion, the submerged macrophytes cannot survive in aquatic ecosystems at NH-N concentrations at or above 15 mg/L, due to loss of photosynthetic capacity. This study revealed the causes of submerged macrophyte degradation in lakes with high NH-N, and provides theoretical guidance for using submerged macrophytes to restore aquatic ecosystems with high NH-N levels.

关 键 词：沉水植物 铵态氮 游离氨基酸 苦草 大茨藻 穿叶眼子菜 

分 类 号：Q945.79[生物学—植物学]