作为最大的商品化食品生产基地和生态安全屏障,黑土区土地退化严重威胁着全球粮食供应和自然生态系统。因此,确定土壤微生物群的响应对恢复退化土壤至关重要。本研究结合宏基因组学和代谢组学研究不同程度土壤退化对黑土微生物群落组成和代谢功能的影响。发现退化土壤(香农:22.3)的α多样性高于未退化土壤(ND)(香农:21.8),降解程度显著改变了土壤微生物群落的结构和组成。LEfSe分析结果获得9(ND),7(轻度退化,LD),10(中度退化,MD),和1(严重退化,SD)四个样品中的生物标志物。缓生根瘤菌,鞘氨醇单胞菌,和Ramlibacter受到土壤退化的显著影响,可以被认为是ND的生物标志物,MD,SD,分别。土壤养分和酶活性随着黑土退化的增加而显著下降,土壤有机质(SOM)含量从11.12%下降到1.97%,蔗糖酶从23.53下降到6.59mg/g/d。此外,C是影响微生物群落结构的关键驱动因素,对微生物群落分布差异的贡献为61.2%,和微生物改变参与碳循环以响应土壤退化的相对丰度。代谢组学分析表明,土壤退化显著改变了土壤代谢谱,大多数微生物对土壤退化的代谢功能受到不利影响。组合的多组学分析进一步表明生物标志物在积累代谢物中占主导地位。这些发现证实,由于它们在这些退化土壤的组成和功能中的作用,这些生物标志物可用于管理和恢复退化黑土的策略。
As the largest commercial food production base and ecological security barrier, land degradation in black soil areas seriously threatens the global food supply and natural ecosystems. Therefore, determining the response of soil microbiota is crucial to restoring degraded soils. This
study combined metagenomics and metabolomics to investigate the effect of different degrees of soil degradation on microbial community composition and metabolic function in black soils. It was found that alpha diversity in degraded soils (Shannon: 22.3) was higher than in nondegraded soil (ND) (Shannon: 21.8), and the degree of degradation significantly altered the structure and composition of soil microbial communities. The results of LEfSe analysis obtained 9 (ND), 7 (lightly degraded, LD), 10 (moderately degraded, MD), and 1 (severely degraded, SD) biomarkers in four samples. Bradyrhizobium, Sphingomonas, and Ramlibacter were significantly affected by soil degradation and can be considered biomarkers of ND, MD, and SD, respectively. Soil nutrient and enzyme activities decreased significantly with increasing black soil degradation, soil organic matter (SOM) content decreased from 11.12 % to 1.97 %, and Sucrase decreased from 23.53 to 6.59 mg/g/d. In addition, C was the critical driver affecting microbial community structure, contributing 61.2 % to differences in microbial community distribution, and microbial altering relative abundance which participle in the carbon cycle to respond to soil degradation. Metabolomic analyses indicated that soil degradation significantly modified the soil metabolite spectrum, and the metabolic functions of most microorganisms responding to soil degradation were adversely affected. The combined multi-omics analysis further indicated that biomarkers dominate in accumulating metabolites. These findings confirmed that due to their role in the composition and functioning of these degraded soils, these biomarkers could be employed in strategies for managing and restoring degraded black soils.