不同氮浓度对塔玛亚历山大藻生长及其氮代谢生理的影响  

Effects of Nitrogenous Nutrition on Growth and Nitrogen Assimilation Enzymes of Dinoflagellate Alexandrium tamarense

作　　者：卜克辛 陈田田 王昕慧[1] 徐溢波 白洁 晨曦[3] Bu Kexin;Chen Tiantian;Wang Xinhui;Xu Yibo;Bai Jie;Chen Xi(College of Environment Science and Engineering,Ocean University of China,Qingdao 266100,China;Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China;College of Marine Life Scienses,Ocean University of China,Qingdao 266003,China)

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [3]中国海洋大学海洋生命学院,山东青岛266003

出　　处：《中国海洋大学学报（自然科学版）》2024年第11期58-64,共7页Periodical of Ocean University of China

基　　金：自然资源部热带海洋生态系统与生物资源重点实验室开放基金项目(2021QN007)资助。

摘　　要：针对近二十年中国高氮磷比海域中亚历山大藻等甲藻引起的赤潮现象频发、规模和范围显著扩大的问题,本研究以塔玛亚历山大藻(Alexandrium tamarense)为实验材料,在不同氮浓度下对A.tamarense进行一次性培养,系统分析了氮浓度对A.tamarense生长生理的影响。结果显示:在缺乏氮源的情况下,A.tamarense的生长受到明显抑制,然而随着氮浓度的逐渐增加,其生长速率加快且叶绿素含量增高,从而其光合作用能力也显著增强;在对数生长期,与高氮培养相比,低氮培养条件下A.tamarense的硝酸还原酶(Nitrate reductase NR)和谷氨酰胺合成酶(Glutamine synthetase,GS)活性升高,而平台期NR和GS活性则是随氮浓度的升高而升高;脲酶(Urea enzymes,UE)活性在各时期均随氮浓度的升高而呈现先升高后降低的趋势。综上结果表明:不同氮浓度对A.tamarense生长生理存在显著影响,相较于低氮培养,A.tamarense更适应于高氮环境下生长;A.tamarense通过调节氮代谢酶活性以应对氮限制不利环境的影响,这种适应能力使其在面对复杂多变的无机氮条件下更具竞争优势。这些研究结果可为解释氮源影响近岸水域生态系统中甲藻赤潮动态提供一定依据。In recent twenty years,the frequency,scale and scope of red tides caused by dinoflagellates such as Alexandrium have increased significantly in eutrophic waters with high nitrogen-phosphorus ratio in China.Therefore,this study systematically analyzed the effects of nitrogen concentration on the growth physiology of Alexandrium tamarense by a batch culture of A.tamarense under different nitrogen concentrations under laboratory simulation conditions.The result indicated that the growth of A.tamarense was significantly inhibited under nitrogen-limited conditions.With the increase of nitrogen concentration,the growth rate of A.tamarense accelerated,which corresponds to the increase of chlorophyll content and photosynthesis capacity.In the exponential phase,the nitrate reductase(NR)and glutamine synthetase(GS)activity of A.tamarense increased under low nitrogen conditions compared with high nitrogen conditions.However,the NR and GS activity of A.tamarense increased with increasing nitrogen concentration in the stationary period.Additionally,in all growth periods,with the increase of nitrogen concentration,the urease(UE)activity of A.tamarense increased firstly and then decreased.Overall,the different nitrogen concentrations had significant effects on the growth and physiology of A.tamarense,and A.tamarense preferred high nitrogen rather than low nitrogen conditions.Under nitrogen-limited conditions,A.tamarense could cope with the negative conditions of nitrogen limitation by regulating the activities of nitrogen metabolism enzymes,which made it more competitive in dealing with complex and variable inorganic nitrogen conditions.This study would provide a deep insight into the influence of nitrogen sources on the dynamics of dinoflagellate blooms in coastal water ecosystems.

关 键 词：塔玛亚历山大藻 氮浓度 氮代谢酶 赤潮 富营养化 生长 光合作用 

分 类 号：X55[环境科学与工程—环境工程]