Department of Biological Sciences, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.
Department of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030, USA.
Chemosphere. 2023 Nov;340:139812. doi: 10.1016/j.chemosphere.2023.139812. Epub 2023 Aug 17.
The use of arsenic (As) for various industrial and agricultural applications has led to worldwide environmental contamination. Phytoremediation using hyperaccumulators is a sustainable soil As mitigation strategy. Microbial processes play an important role in the tolerance and uptake of trace elements such as in plants. The rhizospheric and endophytic microbial communities are responsible for accelerating the mobility of trace elements around the roots and the production of plant growth-promoting compounds and enzymes. Several studies have reported that the As hyperaccumulator, Pteris vittata L. (PV) influences the microbial community in its rhizosphere and roots. Deciphering the differences in the microbiomes of hyperaccumulators and non-accumulators is crucial in understanding the mechanism of hyperaccumulation. We hypothesized that there are significant differences in the microbiome of roots, rhizospheric soil, and bulk soil between the hyperaccumulator PV and a non-accumulator of the same genus, Pteris ensiformis Burm. (PE), and that the differential recruitment of bacterial communities provides PV with an advantage in As contaminated soil. We compared root endophytic, rhizospheric, and bulk soil microbial communities between PV and PE species grown in As-contaminated soil in a greenhouse setting. There was a significant difference (p < 0.001) in the microbiome of the three compartments between the ferns. Differential abundance analysis showed 328 Amplicon Sequence Variants (ASVs) enriched in PV compared to 172 in PE. The bulk and rhizospheric soil of both ferns were abundant in As-resistant genera. However, As-tolerant root endophytic genera were present in PV but absent in PE. Our findings show that there is a difference between the bacterial composition of an As hyperaccumulator and a non-accumulator species grown in As-contaminated soil. These differences need to be further explored to develop strategies for improving the efficiency of metal uptake in plants growing in As polluted soil.
砷（As）在各种工业和农业应用中的使用导致了全球环境污染。利用超富集植物进行植物修复是一种可持续的土壤砷缓解策略。微生物过程在植物等痕量元素的耐受和吸收中起着重要作用。根际和内生微生物群落负责加速根系周围痕量元素的迁移以及植物生长促进化合物和酶的产生。有几项研究报告称，砷超富集植物凤尾蕨（PV）会影响其根际和根部的微生物群落。解析超富集植物和非富集植物的微生物组之间的差异对于理解超富集的机制至关重要。我们假设，超富集植物 PV 和同属的非富集植物凤尾蕨（PE）的根、根际土壤和土壤宏基因组之间的微生物组存在显著差异，并且细菌群落的差异招募为 PV 在砷污染土壤中提供了优势。我们比较了在温室条件下生长于砷污染土壤中的 PV 和 PE 种的根内生、根际和土壤宏基因组微生物群落。两种蕨类植物的三个隔室的微生物组存在显著差异（p<0.001）。差异丰度分析显示，与 PE 相比，PV 中有 328 个扩增子序列变异（ASV）富集。两种蕨类植物的根际和土壤宏基因组均富含砷抗性属。然而，在 PV 中有但在 PE 中没有耐砷根内生属。我们的研究结果表明，在砷污染土壤中生长的砷超富集植物和非富集植物的细菌组成存在差异。需要进一步探索这些差异，以开发提高在砷污染土壤中生长的植物金属吸收效率的策略。
