Aims

To investigate the effects of polystyrene microplastics (PS-beads) on the soil properties, photosynthesis of Flowering Chinese cabbage, the rhizosphere microbial community and their potential correlation in soil with different residues.

Methods

The influences of PS-beads (PS-MPs, M1, 5 μm; PS-NPs, M2, 70 nm) on the plant photosynthesis and growth parameters, soil dissolved organic matter (DOM) and the characteristic functional groups, the microbial community and metabolism prediction were studied by a pot-experiment in soil without residues (N), with biochar (B), degradable mulching film (DMF) fragments (D), or biochar and DMF (BD).

Key results

Chlorophyll a was more susceptible to the exogenous substances than Chlorophyll b. In soil with different residues, PS-beads of different sizes could change different components, structures and functional groups in aromatic rings of DOM, might further change the microbial community and metabolism. M2 decreased TDN and NO₃⁻ and increased the weight of the plant in group D. M2 increased the weight of the plant in group N. M2 decreased the net photosynthetic rate in group B. The different sizes of PS-beads affected the different parameters of plant growth and potentially changed the plant growth and photosynthetic parameters through altering the microbial metabolism and the correlation among microbes. The potential mechanisms of PS-beads changing the plant growth were different in soil with different residues.

Conclusions

Our results evidenced the PS-beads potentially changed the plant growth and photosynthesis by changing the microbial metabolism and the correlation among microbes.

中文翻译：

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土壤-植物系统中的微塑料：纳米/微塑料对不同残留量土壤中植物光合作用，根际微生物和土壤特性的影响

目的

研究聚苯乙烯微塑料（PS-beads）对土壤特性，大白菜光合作用，根际微生物群落及其在不同残留量土壤中的潜在相关性的影响。

方法

PS-珠（PS-MPs，M1，5μm； PS-NPs，M2，70 nm）对植物光合作用和生长参数，土壤可溶性有机物（DOM）和特征性官能团，微生物群落和微生物的影响通过在没有残留物（N），含有生物炭（B），可降解覆盖膜（DMF）碎片（D）或生物炭和DMF（BD）的土壤中进行盆栽试验，研究了代谢预测。

关键结果

叶绿素a比叶绿素b更容易受到外源物质的影响。在残留不同的土壤中，不同大小的PS珠可改变DOM芳香环中不同的组分，结构和官能团，可能进一步改变微生物群落和代谢。M2降低TDN和NO ₃ ^-并增加了D组的植物的重量。M2增加了N组的植物的重量。M2降低了B组的净光合速率。不同大小的PS-磁珠影响植物生长的不同参数，并有可能改变通过改变微生物的新陈代谢以及微生物之间的相关性来促进植物的生长和光合参数。在残留不同的土壤中，PS珠改变植物生长的潜在机制是不同的。

结论

我们的结果表明，PS珠通过改变微生物的代谢和微生物之间的相关性，可能改变植物的生长和光合作用。