不同繁殖方式对宿根蔗根系内生微生物群落结构与功能的影响

Effects of different propagation methods on the structure and function of endophytic microbial community in ratoon cane roots

关键词:  甘蔗, 宿根蔗, 组织培养, 常规繁殖, 内生微生物

Key words:  sugarcane, ratoon cane, tissue culture, conventional propagation, endophytic microorganisms

摘要:

为探究不同繁殖方式对宿根蔗根系内生细菌、真菌群落结构和功能的影响,该文以组织培养繁殖和常规蔗茎繁殖方式下宿根蔗根系为研究对象,采用高通量测序技术,分析了宿根蔗根系内生微生物群落的结构特征,并利用PICRUSt软件和FUNGuild 软件分别对细菌群落和真菌群落进行了功能预测。结果表明:(1)与常规蔗茎繁殖方式相比,组织培养繁殖方式改变了宿根蔗根系内生微生物群落组成。(2)常规蔗茎繁殖方式下特有的优势内生细菌属包括雷夫松氏菌属(Leifsonia)、叶杆菌属(Phyllobacterium)、norank_f__Micropepsaceae、海无柄孢囊黏细菌属(Haliangium)、小粒胞菌属(Granulicella)、酸栖热菌属(Acidothermus)、norank_f__Acetobacteraceae、norank_f__Magnetospirillaceae属细菌; 优势内生真菌属包括粗糙孔菌属(Trechispora)、Hypochnicium、unclassified_o__Trechisporales、小菇属(Mycena)、Chaetosphaeria、Cladophialophora、木霉菌属(Trichoderma)真菌。(3)组织培养繁殖方式下宿根蔗根系特有的优势内生细菌属包括罗尔斯通氏菌属(Ralstonia)、拟无枝酸菌属(Amycolatopsis)、unclassified_f__Pseudonocardiaceae、德沃斯氏菌属(Devosia)、链霉菌属(Streptomyces)、列契瓦尼尔氏菌属(Lechevalieria)、拟孢囊菌属(Kibdelosporangium)细菌; 优势内生真菌属包括unclassified_f__Marasmiaceae、unclassified_k__Fungi、青霉菌属(Penicillium)、帚枝霉属(Sarocladium)、unclassified_c__Agaricomycetes、Setophoma属真菌。(4)组织培养繁殖方式下宿根蔗根系内生菌的OTUs数量明显大于常规蔗茎繁殖方式下的OTUs数量,具有更丰富的内生微生物种类和数量。(5)功能预测结果显示,两种繁殖方式下宿根蔗根系内生细菌功能相似,但内生真菌中的内生真菌-植物病原体-未定义腐生菌类群在组织培养宿根蔗中显著富集。综上认为,不同繁殖方式影响了宿根蔗根系内生微生物群落的组成结构与功能,该研究结果为后期筛选和开发利用有益功能微生物种群提供了理论依据。

Abstract:

To investigate the effects of different propagation methods on the structures and functions of endophytic bacterial and fungi in ratoon cane roots, the ratoon cane roots were analyzed based on high-throughput sequencing technology. In this study, ratoon cane roots via tissue culture and conventional propagation methods were used as the materials. Meanwhile, the functions of bacterial and fungal communities were also predicted using PICRUSt and FUNGuild softwares, respectively. The results were as follows:(1)The dominant endophytic microbial communities in ratoon cane roots were different between conventional propagation and tissue culture propagation methods.(2)The unique dominant endophytic bacterial genera in ratoon cane roots under the conventional propagation method included Leifsonia, Phyllobacterium, norank_f__Micropepsaceae, Haliangium, Granulicella, Acidothermus, norank_f__Acetobacteraceae and norank_f__Magnetospirillaceae; meanwhile, the unique dominant endophytic fungal genera were Trechispora, Hypochnicium, unclassified_o__Trechisporales, Mycena, Chaetosphaeria, Cladophialophora and Trichoderma.(3)In the ratoon cane roots under the tissue culture propagation method, the unique dominant endophytic bacterial genera included Ralstonia,Amycolatopsis,unclassified_f__Pseudonocardiaceae, Devosia, Streptomyces, Lechevalieria and Kibdelosporangium, and the unique dominant endophytic fungal genera included unclassified_f__Marasmiaceae, unclassified_k__Fungi, Penicillium, Sarocladium, unclassified_c__Agaricomycetes and Setophoma. Compared with the conventional propagation method, the endophytic microbial compositions in ratoon cane roots could be altered by the tissue culture propagation method.(4)The numbers of unique operational taxonomic units(OTUs)of endophytic bacteria and fungi in ratoon cane roots under the tissue culture propagation method was greater than that under the conventional propagation method, indicating higher endophytic microbial diversity and abundance.(5)The functional prediction results showed that the functions of endophytic bacteria in ratoon cane roots were similar between conventional and tissue culture propagation methods, however, the endophyte-plant pathogen-undefined saprotroph group of endophytic fungi was significantly enriched under tissue culture propagation method. In conclusions, endophytic microbial community structures and functions in ratoon cane roots are affected by different propagation methods. All above results also provide a theoretical basis for the subsequent screening, development, and utilization of beneficial functional microbial populations.