PDF(Pubmed)
Abstract：
Over-application of chemical fertilizers and continuous cropping obstacles seriously restrict the sustainable development of tobacco production. Localized fertilization of beneficial microbes has potential advantages in achieving higher productivity, but the underlying biological mechanisms of interactions between rhizospheric microorganisms and the related metabolic cycle remain poorly characterized. Here, an integrative analysis of microbiomes with non-targeted metabolomics was performed on 30 soil samples of rhizosphere, root surrounding, and bulk soils from flue-cured tobacco under continuous and non-continuous monocropping systems. The analysis was conducted using UPLC-MS/MS platforms and high-throughput amplicon sequencing targeting the bacterial 16S rRNA gene and fungal ITS gene. The microbial inoculant consisted of Bacillus subtilis, B. velezensis, and B. licheniformis at the ratio of 1:1:1 in effective microbial counts, improved the cured leaf yield and disease resistance of tobacco, and enhanced nicotine and nitrogen contents of tobacco leaves. The bacterial taxa Rhizobium, Pseudomonas, Sphingomonadaceae, and Burkholderiaceae of the phylum Proteobacteria accumulated in high relative abundance and were identified as biomarkers following the application of the microbial inoculant. Under continuous monocropping, metabolomics demonstrated that the application of the microbial inoculant significantly affected the soil metabolite spectrum, and the differential metabolites were significantly enriched to the synthesis and degradation of nicotine (nicotinate and nicotinamide metabolism and biosynthesis of alkaloids derived from nicotinic acid). In addition, microbes were closely related to the accumulation of metabolites through correlation analysis. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.IMPORTANCEThis study elaborated on how the microbial fertilizer significantly changed overall community structures and metabolite spectrum of rhizospheric microbes, which provide insights into the process of rhizosphere microbial remolding in response to continuous monocropping. we verified the hypothesis that the application of the microbial inoculant in continuous cropping would lead to the selection of distinct microbiota communities by establishing models to correlate biomarkers. Through correlation analysis of the microbiome and metabolome, we proved that rhizospheric microbes were closely related to the accumulation of metabolites, including the synthesis and degradation of nicotine. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.
摘要：
化肥的过度施用和连作障碍严重制约了烟叶生产的可持续发展。有益微生物的局部施肥在实现更高的生产率方面具有潜在的优势，但是根际微生物与相关代谢循环之间相互作用的潜在生物学机制仍然缺乏表征。这里,对30个根际土壤样本进行了非靶向代谢组学的微生物群落综合分析，根周围，以及连续和非连续单作系统下烤烟的散装土壤。使用UPLC-MS/MS平台和靶向细菌16SrRNA基因和真菌ITS基因的高通量扩增子测序进行分析。微生物接种剂由枯草芽孢杆菌组成，B.velezensis，和地衣芽孢杆菌以1:1:1的比例有效微生物计数，提高了烤烟的产量和抗病性，提高了烟叶的烟碱和氮含量。细菌类群根瘤菌，假单胞菌,Sphingomonadaceae，和蛋白质门的伯克氏菌科积累了较高的相对丰度，并在应用微生物接种剂后被鉴定为生物标志物。在连续的一刀切下，代谢组学表明，微生物接种剂的应用显著影响了土壤代谢物谱，差异代谢产物显著富集于烟碱的合成和降解(烟酸盐和烟酰胺代谢以及烟酸生物碱的生物合成)。此外,通过相关性分析，微生物与代谢产物的积累密切相关。植物根与根际微生物之间的相互作用为了解这些有益微生物如何影响复杂的生物过程以及植物对环境的适应能力提供了有价值的信息。本研究阐述了微生物肥料如何显着改变根际微生物的总体群落结构和代谢谱，这提供了对连续单作反应的根际微生物重塑过程的见解。通过建立相关生物标志物模型，我们验证了在连作中应用微生物接种剂将导致不同微生物群落的选择这一假设。通过对微生物组和代谢组的相关性分析,我们证明了根际微生物与代谢产物的积累密切相关，包括尼古丁的合成和降解。植物根与根际微生物之间的相互作用为了解这些有益微生物如何影响复杂的生物过程以及植物对环境的适应能力提供了有价值的信息。
