MOE Key Lab of Environmental Remediation and Ecosystem Health, and Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Environ Sci Technol. 2021 Feb 2;55(3):1555-1565. doi: 10.1021/acs.est.0c03924. Epub 2021 Jan 15.
Bioavailability and speciation of arsenic (As) are impacted by fertilization and bacteria in the rice rhizosphere. In this study, we investigated the effects of long-term manure application on As bioavailability, microbial community structure, and functional genes in a rice paddy field. The results showed that manure application did not affect total As in the soil but increased soluble As forms by 19%, increasing arsenite (As(III)) accumulation in rice grains and roots by 34 and 64% compared to a control. A real-time quantitative polymerase chain reaction (qPCR) and high-throughput sequencing analysis demonstrated that manure application increased the relative abundance of , , , and containing arsenate reductase genes () in the rhizosphere soil, consistent with the 529% increase in , which may have promoted arsenate (As(V)) reduction and increased As availability in pore water. In addition, manure application significantly altered the iron (Fe)-plaque microbial community structure and diversity. The microbes, particularly, , , and , were mostly associated with As, Fe, and sulfur (S) cycles. This result was consistent with changes in the functional genes related to As, Fe, and S transformation. Although manure application promoted As(V) reduction ( in Fe-plaque by 682%, it inhibited Fe and S reduction by decreasing Fe reduction bacteria (Geobacteraceae) and the sulfate-reducing gene () abundance. Further, manure application changed the composition of the microbial community that contained the gene. In short, caution needs to be excised even in the soil with a low As concentration as manure application increased As(III) accumulation in rice grains.
施肥和根际细菌会影响砷（As）的生物利用度和形态。本研究调查了长期施用有机肥对稻田土壤中 As 生物利用度、微生物群落结构和功能基因的影响。结果表明，有机肥的施用并未影响土壤中的总 As 含量，但增加了 19%的可溶性 As 形态，与对照相比，大米籽粒和根系中的砷酸盐（As(III))积累量分别增加了 34%和 64%。实时定量聚合酶链反应（qPCR）和高通量测序分析表明，有机肥的施用增加了根际土壤中砷酸盐还原酶基因（）的相对丰度，与 529%的增加一致，这可能促进了砷酸盐（As(V))还原和增加了孔隙水中的 As 有效性。此外，有机肥显著改变了铁（Fe）斑块微生物群落结构和多样性。这些微生物，特别是、、、和，主要与 As、Fe 和 S 循环有关。这一结果与与 As、Fe 和 S 转化相关的功能基因的变化一致。尽管有机肥的施用促进了 As(V)的还原（Fe 斑块中增加了 682%），但通过减少铁还原菌（Geobacteraceae）和硫酸盐还原基因（）的丰度，它抑制了 Fe 和 S 的还原。此外，有机肥改变了含有基因的微生物群落的组成。总之，即使在 As 浓度较低的土壤中，也需要谨慎施肥，因为有机肥会增加大米籽粒中 As(III)的积累。
