基于高通量测序的橡胶树不同生态位微生物群落多样性分析

Analysis of microbial community diversity in ecological niches of Hevea brasiliensis based on high-throughput sequencing

  • 摘要: 【目的】 基于高通量测序分析橡胶树不同生态位微生物群落多样性,为橡胶树特色微生物资源的开发利用及维持橡胶园生产力提供参考依据。【方法】 以橡胶树RRIM600根、茎、叶和根际土壤4个生态位为研究对象,基于Illumina PE250平台高通量测序获得不同生态位微生物的扩增子序列变体(ASV)的特征序列。分析不同生态位的微生物群落物种组成,鉴定优势菌门和优势菌属。构建物种系统发育树并进行Alpha多样性分析,对微生物群落进行主坐标(PCoA)分析、Beta多样性分析、聚类分析和相关分析。依据线性判别分析效应量(LEfSe)筛选差异显著的微生物群落,并分析不同微生物对不同生态位的影响。【结果】 橡胶树RRIM600的4个生态位真菌ASV总数为4193个,细菌ASV总数为12525个。根、茎、叶和根际土壤中分别含有310、411、140和2762个特有真菌ASV,分别有2312、634、2603和5898个细菌ASV。4个生态位的最优势真菌菌门均为子囊菌门,其中叶中子囊菌门的占比最高,相对丰度达94.00%。除未分类真菌门外,担子菌门也是根、茎和根际土壤中的优势菌门。根、茎、叶和根际土壤中主要优势真菌属分别包括Oliveonia、横断孢属、白粉菌属和枝孢菌属。根、茎、叶和根际土壤4个生态位的优势细菌菌门均为变形菌门,其相对丰度分别为88.41%、99.92%、99.91%和88.33%;共有优势菌属包含气单胞菌属和Thiofilum。真菌群落橡胶树根际土壤的Chao1指数、Observed-features指数和Shannon指数均显著高于根、茎和叶(P<0.05,下同),内生细菌群落的3个指数排序均为根>叶>茎。PCoA分析结果表明,前2个主坐标共解释真菌和细菌群落组成差异的56.48%和44.77%,细菌群落组成呈地上生态位与地下生态位的结构分化。LEfSe分析结果表明,不同生态位的真菌均具有生物标记物,叶无显著富集的细菌群落。相对丰度排名前30的真菌和细菌属相关分析结果表明,有140对真菌呈显著正相关,有20对真菌呈显著负相关;有5对细菌呈显著正相关,有3对细菌呈显著负相关。【结论】 橡胶树RRIM600不同生态位微生物群落在多样性与组成上存在明显分化,其相对丰度与微生物的来源相关,不同生态位对微生物具有选择和过滤作用。

     

    Abstract: 【Objective】 This study aimed to analyze microbial community diversity in ecological niches of Hevea brasiliensis based on high-throughput sequencing, providing reference for development and utilization of characteristic microbial resources, and maintaining rubber plantation productivity. 【Method】 Four ecological niches of Hevea brasiliensis RRIM600, namely roots, stems, leaves, and rhizosphere soil, were taken as the research subjects. High-throughput sequencing based on the Illumina PE250 platform was performed to obtain the characteristic sequences of amplicon sequence variants (ASVs) of microorganisms in different ecological niches. The species composition of microbial communities in different ecological niches was analyzed, and the dominant phyla and dominant genera were identified. A phylogenetic tree of the species was constructed, and alpha diversity analysis was conducted. Principal coordinate (PCoA) analysis, beta diversity analysis, cluster analysis, and correlation analysis were performed on the microbial communities. LDA effect size (LEfSe) was used to screen for significantly different microbial communities, and the effects of different microorganisms on different ecological niches were analyzed. 【Result】 A total of 4193 fungal ASVs and 12525 bacterial ASVs were identified in four ecological niches of Hevea brasiliensis RRIM600. The numbers of unique fungal ASVs in roots, stems, leaves, and rhizosphere soil were 310, 411, 140, and 2762 respectively, while those of bacterial ASVs were 2312, 634, 2603, and 5898 respectively. Ascomycota was the most dominant fungal phylum in all four niches, with the highest relative abundance observed in leaves, reaching 94.00%. Apart from unclassified fungi, Basidiomycota was also the dominant phylum in roots, stems, and rhizosphere soil. The dominant fungal genera in roots, stems, leaves, and rhizosphere soil were OliveoniaStrelitzianaErysiphe, and Cladosporium respectively. Proteobacteria was the dominant bacterial phylum in all four niches, with relative abundances of 88.41%, 99.92%, 99.91%, and 88.33% in roots, stems, leaves, and rhizosphere soil respectively. The shared dominant genera included Aeromonas and Thiofilum. For the fungal community in rhizosphere soil of Hevea brasiliensis, the Chao1 index, observed-features index, and Shannon index were significantly higher than those in roots, stems, and leaves (P<0.05, the same below). For the endophytic bacterial community, the order of the three indices was root > leaf > stem. PCoA analysis results showed that the first two principal coordinates explained 56.48% and 44.77% of the variation in fungal and bacterial community composition respectively, and bacterial community composition exhibited a structural differentiation between above-ground and below-ground niches. LEfSe analysis indicated that different ecological niches had biomarkers for fungi, while no significantly enriched bacterial community was detected in leaves. Correlation analysis of the top 30 most abundant fungal and bacterial genera revealed the 140 pairs of fungi showed significantly positive correlations, and 20 pairs of fungi had significantly negative correlations; 5 pairs of bacteria showed significant positive correlations, and 3 pairs of bacteria showed significant negative significant correlations. 【Conclusion】 Microbial community diversity in ecological niches of in Hevea brasiliensis RRIM600 exhibits pronounced differentiation in both diversity and composition, with its relative abundances related to microbial sources, and different ecological niches exert selective and filtering effects on microorganisms.

     

/

返回文章
返回