新疆两种土地利用方式下土壤病毒的群落组成与功能特征

Compositional and functional characteristics of viruses in soil under two types of land⁃use in Xinjiang,China

病毒作为食物网的重要组成部分,在生态系统中发挥着重要的功能。病毒能够影响宿主的死亡率、群落结构和进化,以及营养元素循环。但由于技术方法的限制,对土壤病毒的群落组成和功能特征还知之甚少。为探索不同土地利用方式下土壤病毒组特征,采集了新疆棉花地和荒漠土壤样品。通过宏病毒组学分析发现,棉花地土壤和荒漠土壤分别注释到20个和15个病毒科,单链DNA(ssDNA)病毒占优势,其中微小噬菌体科(Microviridae)占比最高。仅在棉花地土壤中检测到花椰菜花叶病毒科(Caulimoviridae)、逆转录病毒科(Retroviridae)、裸露病毒科(Nudiviridae)、多分DNA病毒科(Polydnaviridae)、杆状病毒科(Baculoviridae)和囊泡病毒科(Ascoviridae),其中大部分病毒属于植物病毒和昆虫病毒。本研究推测与土地利用方式相关的人为活动、土壤理化性质以及动植物的差异可能影响土壤病毒的群落组成。通过Virsorter共注释到1824条病毒contigs,主要为微小噬菌体科。进一步利用SEED数据库对病毒功能进行注释,发现两个土壤病毒组注释到的主要功能类似;在SEED level 2水平上,均以“Phage capsid proteins”和“Phage packaging machinery”占比最高。本研究可为进一步探索土壤病毒生态功能和土壤食物网提供数据支持。

Viruses are an important component of the food web,and have vital functions in the ecosystem.Viruses can affect the mortality,community structure and evolution of their hosts and nutrient cycling.However,we know little about community composition and functional characteristics of viruses in soil,due to technical challenges.To initially explore the characteristics of soil virome under different land⁃use types,cotton soil and desert soil were collected in Xinjiang.Twenty and fifteen viral families were identified from cotton soil and desert soil,respectively,and ssDNA viruses were predominant in both two samples,with Microviridae being the most abundant family.Caulimoviridae,Retroviridae,Nudiviridae,Polydnaviridae,Baculoviridae,and Ascoviridae were only detected in cotton soil,most of which belonged to plant and insect viruses.This study speculates that the difference of human activities,soil physical and chemical properties,plants and animals associated with different land⁃use types might affect viral communities.A total of 1824 viral contigs were identified by Virsorter and mainly annotated to the family Microviridae.Major functions of two viromes were similar by comparison with the SEED database,and at SEED subsystem level 2 annotation,“Phage capsid proteins”and“Phage packaging machinery”accounted for the highest proportion.This study can provide data support for further exploration of soil virus ecological function and soil food web.