Zhou Qingyang, Gao Jingqing, Zhang Ruimin, Zhang Ruiqin
The College of Chemistry and Molecular Engineering/Institute of Environmental Sciences, Zhengzhou University, Zhengzhou, Henan, PR China.
College of Water Conservancy and Environmental Engineering, Zhengzhou University, Zhengzhou, Henan, PR China.
Ecotoxicol Environ Saf. 2017 Sep;143:102-110. doi: 10.1016/j.ecoenv.2017.04.016. Epub 2017 May 16.
Ammonia has been a major reason of macrophyte decline in the water environment, and ammonium ion toxicity should be seen as universal, even in species frequently labeled as "NH specialists". To study the effects of high NH-N stress of ammonium ion nitrogen on tolerant submerged macrophytes and investigate the pathways of nitrogen assimilation in different organisms, Myriophyllum aquaticum was selected and treated with various concentrations of ammonium ions at different times. Increasing of ammonium concentration leads to an overall increase in incipient ammonia content in leaves and stems of plants. In middle and later stages, high concentrations of NH ion nitrogen taken up by M. aquaticum decreased, whereas the content of NO ion nitrogen increased. Moreover, in M. aquaticum, the activities of the enzymes nitrate reductase, glutamine synthetase and asparagine synthetase changed remarkably in the process of alleviating NH toxicity and deficiency. The results of the present study may support the studies on detoxification of high ammonium ion content in NH-tolerant submerged macrophytes and exploration of tissue-specific expression systems.
氨一直是水环境中大型植物衰退的主要原因，铵离子毒性应被视为普遍存在的，即使在常被标记为“NH specialists”的物种中也是如此。为了研究铵离子态氮的高 NH-N 胁迫对耐氨沉水植物的影响，并探究不同生物体内氮同化的途径，选取了水生黑藻并在不同时间用不同浓度的铵离子进行处理。铵浓度的增加导致植物叶片和茎中初始氨含量总体增加。在中后期，水生黑藻吸收的高浓度 NH 离子态氮减少，而 NO 离子态氮的含量增加。此外，在水生黑藻中，硝酸还原酶、谷氨酰胺合成酶和天冬酰胺合成酶的活性在缓解 NH 毒性和缺乏的过程中发生了显著变化。本研究结果可能有助于耐氨沉水植物中高铵离子含量解毒的研究以及组织特异性表达系统的探索。
