背景:在黄芪的栽培中过量施用化肥会导致药用植物质量的降低,并损害土壤的可持续生产力。PGPB接种剂是生态农业研究的热点。在黄芪的种植中,筛选出的固氮菌能促进植物生长,然而,它是否可以促进主要生物活性成分的积累仍然未知。在这项研究中,含有5株生长促进细菌(根瘤菌T16,中华根瘤菌T21,芽孢杆菌J1,芽孢杆菌G4和节杆菌J2)用于田间试验。采用非靶向代谢组学方法对采收期黄芪根组织中的代谢物质进行鉴定,并通过统计分析鉴定了各组之间的差异代谢物。同时,采用高通量测序技术分析混合微生物处理后根际土壤和内生微生物群落结构的变化。
结果:非靶向代谢的结果表明,治疗后26种代谢物的水平显着增加,其中包括13种黄酮类化合物,3皂苷和10个其他组分。三种植物激素(脱落酸,水杨酸和亚精胺)治疗后也增加,推测在调节植物生长和代谢中起重要作用。对内圈和根际细菌群落的研究表明,微单孢科,和内生植物中的低微生物科,治疗后根际草酸明显增多。这些发现表明它们在促进植物生长和次生代谢调节中的潜在重要性。
结论:这一发现为开发固氮菌肥、提高黄芪生态种植效率提供了依据。
BACKGROUND: The excessive application of chemical fertilizers in the cultivation of Astragalus mongholicus Bunge results in a reduction in the quality of the medicinal plant and compromises the sustainable productivity of the soil. PGPB inoculant is a hot topic in ecological agriculture research. In the cultivation of Astragalus mongholicus, the screened nitrogen-fixing bacteria can promote plant growth, however, whether it can promote the accumulation of main bioactive components remains unknown. In this study, mixed inoculants containing 5 strains of growth promoting bacteria (
Rhizobium T16 , Sinorhizobium T21 , Bacillus J1 , Bacillus G4 and Arthrobacter J2) were used in the field experiment. The metabolic substances in the root tissues of Astragalus mongholicus were identified during the harvest period by non-targeted metabolomics method, and the differential metabolites between groups were identified by statistical analysis. Meanwhile, high-throughput sequencing was performed to analyze the changes of rhizosphere soil and endophytic microbial community structure after mixed microbial treatment.
RESULTS: The results of non-targeted metabolism indicated a significant increase in the levels of 26 metabolites after treatment including 13 flavonoids, 3 saponins and 10 other components. The contents of three plant hormones (abscisic acid, salicylic acid and spermidine) also increased after treatment, which presumed to play an important role in regulating plant growth and metabolism. Studies on endosphere and rhizosphere bacterial communities showed that Rhzobiaceae, Micromonosporaceae, and Hypomicrobiaceae in endophytic, and Oxalobactereae in rhizosphere were significantly increased after treatment. These findings suggest their potential importance in plant growth promotion and secondary metabolism regulation.
CONCLUSIONS: This finding provides a basis for developing nitrogen-fixing bacteria fertilizer and improving the ecological planting efficiency of Astragalus mongholicus.