Background and aims

Increased soil salinization is the major cause of soil degradation. With the increase in soil salinization, accompanied by nutrient deficiency, the mechanisms of improving nutrient uptake and utilization by rhizosphere microorganisms under saline-alkaline conditions are largely unknown.

Methods

The growth parameters and accumulation of nutrients by broomcorn millet (Panicum miliaceum L.) were assessed under saline-alkaline conditions. Furthermore, the soil physicochemical properties and the types of rhizosphere microorganisms were determined.

Results

Broomcorn millet adapted to high saline-alkaline conditions by reducing its height and leaf area and increasing its root-shoot ratio. Salinity is an important factor that regulates the composition of the microbial community. Under high salinity (HS) treatment, the rhizosphere reshaped the microbial communities by recruiting specific beneficial microbes, namely Nocardioides, Saccharimonadal, and Nitriliruptoraceae bacteria that promote soil nutrient cycling and Operculomyces, Alternaria and Cryptococcus fungi that are involved in the decomposition of organic matter and the absorption of nutrients. In addition, the microbial community is influenced by the rhizosphere compartment, and more unique fungal operational taxonomic units (OTUs) are recruited in the high salinity rhizosphere (HS_R) compared to the high salinity non-rhizosphere (HS_NR). The changes in the microbial communities may promote the cycling of soil nitrogen (N) and phosphorus (P) in high salinity soil and ultimately promote the accumulation of P in all the organs and improve the N use efficiency of the plants.

Conclusion

The findings of this study reveal the mechanism of the adaptation of broomcorn millet to different levels of salinity stress and provide insights into microbial and fertilizer management in saline-alkali land.

中文翻译：

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不同盐度土壤下粟子养分积累与微生物群落的关系

 背景和目标

土壤盐碱化增加是土壤退化的主要原因。随着土壤盐碱化的增加，伴随着养分缺乏，在盐碱条件下改善根际微生物对养分的吸收和利用的机制在很大程度上是未知的。

 方法

在盐碱条件下评估扫帚小米 （Panicum miliaceum L.） 的生长参数和养分积累。此外，还测定了土壤理化性质和根际微生物的类型。

 结果

扫帚小米通过降低其高度和叶面积并增加其根芽比来适应高盐碱条件。盐度是调节微生物群落组成的重要因素。在高盐度 （HS） 处理下，根际通过招募特定的有益微生物来重塑微生物群落，即促进土壤养分循环的诺卡菌、糖精和硝科细菌以及鳃盖菌、链格孢属和隐球菌参与有机物分解和营养物质吸收的真菌。此外，微生物群落受根际隔室的影响，与高盐度非根际 （HS_NR） 相比，在高盐度根际 （HS_R） 中招募了更多独特的真菌业务分类单元 （OTU）。微生物群落的变化可能促进高盐度土壤氮 （N） 和磷 （P） 的循环，最终促进 P 在各器官中的积累，提高植物的氮素利用效率。

 结论

本研究结果揭示了扫帚玉米粟适应不同盐胁迫水平的机制，并为盐碱地的微生物和肥料管理提供了见解。