Li Yan, He Xuemin, Yuan Hongfei, Lv Guanghui
College of Ecology and Environment, Xinjiang University, Urumqi 830046, China.
Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi 830046, China.
Microorganisms. 2022 Aug 15;10(8):1644. doi: 10.3390/microorganisms10081644.
, a halophytic shrub, has been used to remediate saline soils in northwest China. However, little is known about its root-associated microbial community and how it may be affected by the plant's growth cycle. In this study, we investigate the microbial community structure of by examining three root compartments (rhizosphere, rhizoplane, and endosphere) during four growth stages (vegetative, flowering, fruiting, and senescence). The microbial community diversity and composition were determined by Illumina MiSeq sequencing of the 16S V3-V4 and 18S ITS regions. Proteobacteria, Actinobacteria, Bacteroidetes, Planctomycetes, and Acidobacteria were the dominant bacterial phyla, while Ascomycota, Basidiomycota, and Mortierellomycota were the most dominant fungal phyla. The alpha diversity of the bacterial communities was highest in the rhizosphere and decreased from the rhizosphere to the endosphere compartments; the fungal communities did not show a consistent trend. The rhizosphere, rhizoplane, and endosphere had distinct bacterial community structures among the three root compartments and from the bulk soil. Additionally, PERMANOVA indicated that the effect of rhizocompartments explained a large proportion of the total community variation. Differential and biomarker analysis not only revealed that each compartment had unique biomarkers and was enriched for specific bacteria, but also that the biomarkers changed with the plant growth cycle. Fungi were also affected by the rhizocompartment, but to a much less so than bacteria, with significant differences in the community composition along the root compartments observed only during the vegetative and flowering stages. Instead, the growth stages appear to account for most of the fungal community variation as demonstrated by PCoA and NMDS, and supported by differential and biomarker analysis, which revealed that the fungal community composition in the rhizosphere and endosphere were dynamic in response to the growth stage. Many enriched OTUs or biomarkers that were identified in the root compartments were potentially beneficial to the plant, meanwhile, some harmful OTUs were excluded from the root, implying that the host plant can select for beneficial bacteria and fungi, which can promote plant growth or increase salt tolerance. In conclusion, the root compartment and growth stage were both determinant factors in structuring the microbial communities of , but the effects were different in bacteria and fungi, suggesting that bacterial and fungal community structures respond differently to these growth factors.
盐节木，一种盐生灌木，已被用于中国西北部盐碱地的修复。然而，关于其根系相关微生物群落以及它如何受到植物生长周期影响的了解却很少。在本研究中，我们通过在四个生长阶段（营养期、花期、果期和衰老期）检查三个根系区室（根际、根表和内生菌根）来研究盐节木的微生物群落结构。通过对16S V3 - V4和18S ITS区域进行Illumina MiSeq测序来确定微生物群落的多样性和组成。变形菌门、放线菌门、拟杆菌门、浮霉菌门和酸杆菌门是主要的细菌门类，而子囊菌门、担子菌门和被孢霉门是最主要的真菌门类。细菌群落的α多样性在根际最高，从根际到内生菌根区室逐渐降低；真菌群落没有呈现出一致的趋势。根际、根表和内生菌根在三个根系区室之间以及与原土相比具有不同的细菌群落结构。此外，PERMANOVA分析表明根系区室的影响解释了总群落变异的很大一部分。差异和生物标志物分析不仅揭示了每个区室都有独特的生物标志物并且特定细菌富集，还表明生物标志物随植物生长周期而变化。真菌也受到根系区室的影响，但程度远小于细菌，仅在营养期和花期观察到沿根系区室的群落组成存在显著差异。相反，如PCoA和NMDS所示，生长阶段似乎解释了大部分真菌群落变异，差异和生物标志物分析也支持这一点，其揭示了根际和内生菌根中的真菌群落组成随生长阶段而动态变化。在根系区室中鉴定出许多富集的OTU或生物标志物可能对植物有益，同时，一些有害的OTU被排除在根系之外，这意味着宿主植物可以选择有益细菌和真菌，它们可以促进植物生长或提高耐盐性。总之，根系区室和生长阶段都是构建盐节木微生物群落的决定因素，但对细菌和真菌的影响不同，表明细菌和真菌群落结构对这些生长因子的响应不同。
