Background and aims

Phytoremediation is an environment friendly, sustainable, and aesthetically pleasing technology for remediating heavy metal polluted soil. Earthworms are ubiquitous macrofauna in the soil ecosystem that play an important role in maintaining soil health and fertility. However, the understanding of earthworms' effect on phytoremediation remains limited.

Methods

In a greenhouse experiment, Lolium multiflorum was subjected to three levels of cadmium (0, 20, or 100 mg kg⁻¹) fully crossed with two levels of earthworm treatments (i.e., with or without Eisenia foetida Savigny).

Results

Plant growth was inhibited while the root-shoot ratio and nitrogen accumulation in shoots were increased under 100 mg kg⁻¹ cadmium. Earthworms interacted with cadmium level to affect the total phosphorus content in soil. Furthermore, earthworms enriched specific microorganisms and significantly influenced bacterial communities under 0 and 20 mg kg⁻¹ cadmium. We observed a significant enrichment of specific microbial species in cadmium polluted soil when earthworms were present. Earthworms’ presence increased the sensitivity of fungal communities in soils polluted with cadmium.

Conclusions

Both earthworms and cadmium had certain impacts on the growth of plants, soil properties and microbial communities in root-zone soil. Moreover, the results suggest that earthworms may alleviate some negative effects of cadmium on soil microorganisms. The findings highlight the effect of earthworm on plant performance, soil properties, and root-zone microbial communities under cadmium stress, providing valuable insights into its role in phytoremediation of soils polluted with metals.

中文翻译：

---

镉胁迫下蚯蚓对黑麦草生长性能、土壤性质及根区土壤微生物群落的影响

 背景和目标

植物修复是一种环境友好、可持续且美观的重金属污染土壤修复技术。蚯蚓是土壤生态系统中普遍存在的大型动物，在维持土壤健康和肥力方面发挥着重要作用。然而，对蚯蚓对植物修复作用的了解仍然有限。

 方法

在温室实验中，黑麦草经受三个水平的镉（0、20或100 mg kg ^-1 ），与两个水平的蚯蚓处理（即，有或没有赤爱胜蚓）完全杂交。

 结果

镉浓度100 mg·kg ^-1时，植物生长受到抑制，但根冠比和地上部氮积累量增加。蚯蚓与镉水平相互作用影响土壤中的总磷含量。此外，蚯蚓富集了特定的微生物，并在0和20 mg kg ^-1镉浓度下显着影响细菌群落。我们观察到当蚯蚓存在时，镉污染土壤中特定微生物种类显着富集。蚯蚓的存在增加了镉污染土壤中真菌群落的敏感性。

 结论

蚯蚓和镉均对植物生长、土壤性质和根区土壤微生物群落产生一定影响。此外，结果表明，蚯蚓可以减轻镉对土壤微生物的一些负面影响。研究结果强调了镉胁迫下蚯蚓对植物性能、土壤特性和根区微生物群落的影响，为了解其在金属污染土壤的植物修复中的作用提供了宝贵的见解。