荒漠孑遗植物四合木对土壤古菌群落的影响

Abstract

土壤是植物定居的场所，也是植物-微生物互作的重要界面。古菌是土壤微生物重要组份，在碳、氮、硫、铁等元素的生物地球化学循环和植物的生长发育、适应生境中发挥重要作用。植物定居对土壤古菌群落的影响研究鲜有开展，孑遗植物在研究植物-微生物-环境互作中具有独特的优势。采用扩增子高通量测序技术，研究以荒漠孑遗植物四合木为建群种或优势种的四合木-红砂-珍珠-针茅群落、四合木-针茅群落和四合木群落等三种荒漠植物群落类型中，四合木根区土壤和光板地土体土壤古菌群落特征，揭示四合木定居对土壤古菌物种数量、多样性、群落组成及功能的影响。结果表明，荒漠孑遗植物四合木定居不仅增加了根区土壤古菌的物种数量，提高了根区土壤古菌群落多样性，而且改变了土壤古菌群落组成，减少了奇古菌门Nitrososphaeraceae科未分类的属氨氧化古菌（unclassified_f_Nitrososphaeraceae）和暂定Nitrososphaera属氨氧化古菌（Candidatus Nitrososphaera）相对丰度，增加了Nitrososphaeraceae科暂定Nitrocosmicus属氨氧化古菌（Candidatus Nitrocosmicus）和广古菌门海洋古菌类群Ⅱ中未分类的属（norank_o_Marine_Group_II）相对丰度，广古菌门热原体纲未分类的属（unclassified_c__Thermoplasmata）相对丰度变化显著。植物群落演替对四合木根区土壤和光板地土体土壤古菌群落均无显著影响。Nitrososphaeraceae科氨氧化古菌是三种不同荒漠植物群落类型中土壤古菌的核心微生物组。四合木定居也显著改变土壤古菌群落的功能，减弱了高丰度功能，增强了低丰度功能，对有氧呼吸、核苷酸合成、氨基酸合成等途径影响显著。荒漠孑遗植物四合木定居改变了土壤古菌群落物种数量、多样性、组成、功能等特征。;Soil is the place where plants colonize and an important interface between plant and microorganism interaction. Archaea is an important component of soil microorganism and plays an important role in the biogeochemical cycle of carbon, nitrogen, sulfur and iron, and in the growth, the development and adaptation to the environment of plants. It is rarely reported the influence of plant colonization on the archaeal community in soil. The relict plants have special advantages in the study of interaction among plant, microbe and environment. In this paper, the archaea in rhizosphere soil in relict plant Tetraena mongolica and barren soil obtained from three different communities of desert plants including the community of Tetraena mongolica, Reaumuria songarica, Salsola passerine and Stipa capillata, the community of Tetraena mongolica and Stipa capillata and the community of Tetraena mongolica where Tetraena mongolica is the dominant species or constructive species were studied to explore the effect of relict plant Tetraena mongolica colonization on the number, the diversity, the composition and the function of archaeal community using the high-throughput sequencing method. The results showed that the diversity and the number of species in archaeal community of rhizosphere soil increased with relict plant Tetraena mongolica colonization. Meanwhile, the composition of archaeal community in soil were changed with relict plant Tetraena mongolica colonization. The relative abundance of ammonia oxidizing archaea of genera unclassified_f_Nitrososphaeraceae of phylum Thaumarchaeota and ammonia oxidizing archaea of Candidatus Nitrososphaera of phylum Thaumarchaeota in rhizosphere soil decreased, while the relative abundance of ammonia oxidizing archaea of genera Candidatus Nitrocosmicu of phylum Thaumarchaeota and norank_o_Marine_Group_II of phylum Euryarchaeota in rhizosphere soil increased. There was no obvious change on the relative abundance of unclassified_c__Thermoplasmata of phylum Euryarchaeota. However, the succession of plant communities had no significant effect on the archaea communities in the rhizosphere soil of relict plant Tetraena mongolica and barren soil. Ammonia oxidizing archaea of family Nitrososphaeraceae is the core microbiome of archaeal communities in soil obtained from three different communities of desert plants. Furthermore, the relict plant Tetraena mongolica colonization greatly changed the function of archaeal community in soil. The high abundant function of archaeal community in soil was weakened and the low abundant function of was enhanced. There was significant effect on aerobic respiration, the pathway of nucleotide biosynthesis and the pathway of amino acid biosynthesis.The relict plant Tetraena mongolica colonization has changed characteristics of archaeal community in desert soil including the number of species, the diversity and the species composition, the function, etc.