云南不同高原湖泊噬藻体psbA基因多样性

Phylogenetic diversity of cyanophage psbA gene in the different plateau lakes in Yunnan Province

【目的】噬藻体(cyanophage)广泛存在于自然水体生态系统中,通过侵染蓝藻进而调控蓝藻种群及群落结构,具有重要生态功能和生态地位,在控制蓝藻水华方面有巨大开发潜力。本研究旨在探究云南高原湖泊噬藻体psbA基因多样性,分析其系统进化地位,为深入了解高原湖泊生态功能、开发利用噬藻体资源奠定理论基础。【方法】以云南高原主要湖泊滇池、抚仙湖和星云湖等为研究对象,以psbA基因作为分子靶标,对湖泊水体中噬藻体遗传多样性进行研究。【结果】从不同湖泊中共获得100条环境噬藻体psbA基因序列,系统发育分析表明,湖泊的噬藻体psbA基因序列与中国东湖、中国东北稻田、日本稻田等淡水中的环境噬藻体psbA基因亲缘关系较近,与海洋环境噬藻体psbA基因亲缘关系较远;抚仙湖中的噬藻体psbA基因多样性高于滇池、星云湖和异龙湖中的噬藻体psbA基因多样性;云南高原湖泊中存在新的噬藻体类群;各湖泊秋冬季节噬藻体psbA基因遗传多样性差异不明显。【结论】云南主要高原湖泊噬藻体psbA基因遗传多样性高,与淡水环境噬藻体psbA基因亲缘关系较近,且存在独特的噬藻体类群。

[Objective]Cyanophages are ubiquitous in natural water ecosystems and have an important ecological status and function.They play a role in controlling cyanobacterial populations and community structure by infecting cyanobacteria,which indicates the great application potential of cyanophages in controlling cyanobacterial blooms.This study aims to explore the diversity and phylogenetic status of cyanophage psbA gene in the plateau lakes in Yunnan Province,so as to lay a theoretical foundation for further understanding the ecological role of cyanophages in plateau lakes and exploiting cyanophage resources.[Methods]The psbA gene was used as a molecular target to study the genetic diversity of cyanophages in Dianchi Lake,Fuxian Lake,and Xingyun Lake in Yunnan Province.[Results]A total of 100psbA sequences of cyanophages were obtained from different lakes.The phylogenetic analysis showed that the psbA gene from the lakes had close genetic distance to those in the East Lake in China,the paddy water in northeast China,and the Japanese paddy floodwater,but were more distantly related to those in the marine waters.The diversity of cyanophage psbA gene in Fuxian Lake was higher than that in Dianchi Lake,Xingyun Lake,and Yilong Lake.The novel psbA assemblies of cyanophage existed in the plateau lakes in Yunnan Province.The genetic diversity of psbA gene showed no significant difference between autumn and winter.[Conclusion]The psbA gene of cyanophages in the main plateau lakes in Yunnan Province has high genetic diversity and is closely related to the psbA gene of cyanophage in freshwater environment.Moreover,there are novel psbA assemblies of cyanophages in the plateau lakes.