Department of Chemistry and Biology "A. Zambelli", University of Salerno, Fisciano, SA, Italy.
Department of Chemistry and Biology "A. Zambelli", University of Salerno, Fisciano, SA, Italy.
Chemosphere. 2020 Jul;251:126310. doi: 10.1016/j.chemosphere.2020.126310. Epub 2020 Feb 27.
Arsenic-(As) pollution is an increasing threat across the globe and it is reaching harmful values in several areas of the world. In this perspective, we assayed bio-phyto-remediation technology using Arundo donax L., assisted by Plant Growth Promoting Bacteria (PGPB) consortium (BC) constituted of two strains of Stenotrophomonas maltophilia sp. and one of Agrobacterium sp.; furthermore, we assayed the epigenetic response to As pollution. The three bacterial strains initially evaluated for their As tolerance, revealed different resistance to both forms of As[As(III) and As(V)] however at concentration greater than those foreseen in the phytoremediation experiment (2.0, 10.0, 20.0 mgL of NaAsO). At the end of the trial plant biomass and As concentration were measured. Plants did not show any visible signs of toxicity, rather the leaf and stem biomass slightly increased in the presence of As and/or PGPBs; moreover, although the Bioaccumulation Factor was double in the presence of BC, the absolute values of As accumulation in the Arundo plants were very low, both in the presence or absence of BC and only detectable in the presence of the highest As dose (20 mgL As). In this case, regardless the presence of PGPB, ≈25% of As remained in the sand and ≈0.15% was accumulated in the plant, whilst the remaining 75% was volatilized by transpiration. Finally, the methylation sensitive amplified polymorphisms (MSAP) of leaves were analyzed in order to investigate their epigenetic response to As and/or BC. Our results suggest that epigenetic modifications are involved in stress response and As detoxification.
砷（As）污染是全球范围内日益严重的威胁，在世界上的几个地区已经达到了有害的程度。从这个角度来看，我们使用多花黑麦草（Arundo donax L.）进行生物-植物修复技术，并辅以植物生长促进细菌（PGPB）联合体（BC），BC 由两种 Stenotrophomonas maltophilia sp. 和一种 Agrobacterium sp.组成；此外，我们还检测了对砷污染的表观遗传反应。最初评估了这三种细菌菌株对砷的耐受性，发现它们对两种形式的砷[As（III）和 As（V）]都有不同的抗性，但在浓度高于植物修复实验预期的浓度（2.0、10.0、20.0 mgL 的 NaAsO）时。试验结束时测量了植物生物量和砷浓度。植物没有表现出任何明显的毒性迹象，而是在存在砷和/或 PGPB 的情况下，叶片和茎生物量略有增加；此外，尽管在 BC 存在的情况下生物累积因子增加了一倍，但 Arundo 植物中砷的绝对积累值非常低，无论是在 BC 存在与否的情况下，并且只有在存在最高砷剂量（20 mgL As）时才可以检测到。在这种情况下，无论是否存在 PGPB，约 25%的砷仍留在沙子中，约 0.15%积累在植物中，而其余 75%通过蒸腾作用挥发。最后，分析了叶片的甲基化敏感扩增多态性（MSAP），以研究它们对砷和/或 BC 的表观遗传反应。我们的结果表明，表观遗传修饰参与了应激反应和砷解毒。
