LPG, UMR 6112 CNRS-Université de Nantes, BP 92208, 44322 Nantes cedex 3, France.
OSUNA, UMS 3281 CNRS-Université de Nantes, BP 92208, 44322 Nantes cedex 3, France.
Sci Total Environ. 2022 Feb 25;809:152113. doi: 10.1016/j.scitotenv.2021.152113. Epub 2021 Dec 4.
Bioaugmentation-assisted phytoextraction was used to reduce the Cu load in vineyard soils. While performance is usually the endpoint of such studies, here we identified some mechanisms underlying Cu soil to plant transfer, particularly the role of siderophores in the extraction of Cu from the soil-bearing phases and its phytoavailability. Carbonated vs. non‑carbonated vineyard soils were cultivated with sunflower in rhizoboxes bioaugmented with Pseudomonas putida. gfp-Tagged P. putida was monitored in the soil and pyoverdine (Pvd), Cu, Fe, Mn, and Zn were measured in the soil solution. Trace elements (TE) were analysed in the roots and shoots. Plant growth and nutritional status were also measured. With bioaugmentation, the concentration of total Cu (vs. Cu) in the soil solution increased (decreased) by a factor of 1.6 to 2.6 (7 to 13) depending on the soil. The almost 1:1 relationship between the excess of Fe + Cu mobilized from the solid phase and the amount of Pvd in the soil solution in bioaugmented treatments suggests that Pvd mobilized Fe and Cu mainly by ligand-controlled dissolution via a 1:1 metal-Pvd complex. Bioaugmentation increased the Cu concentration by 17% in the shoots and by 93% in the roots, and by 30% to 60% the sunflower shoot biomass leading to an increase in the amount of Cu phytoextracted by up to 87%. The amount of Fe, Mn, Zn, and P also increased in the roots and shoots. Contrary to what was expected, carbonated soil did not increase the mobilization of TE. Our results showed that bioaugmentation increased phytoextraction, and its performance can be further improved by promoting the dissociation of Pvd-Cu complex in the solution at the soil-root interface.
生物强化辅助植物提取用于减少葡萄园土壤中的铜负荷。虽然性能通常是此类研究的终点，但在这里，我们确定了铜从土壤到植物转移的一些机制，特别是铁载体在从土壤承载相中提取铜及其植物可利用性方面的作用。在添加了铜绿假单胞菌的根盒中，用向日葵对碳酸化和非碳酸化的葡萄园土壤进行了培养。标记了 gfp 的铜绿假单胞菌在土壤中进行了监测，并且在土壤溶液中测量了吡咯并[2,3-f]喹啉-1,4-二酮（Pvd）、铜、铁、锰和锌。在根系和茎叶中分析了微量元素（TE）。还测量了植物的生长和营养状况。通过生物强化，土壤溶液中总铜（与 Cu 相比）的浓度增加（减少）了 1.6 至 2.6 倍（7 至 13 倍），具体取决于土壤。在生物强化处理中，从固相中释放的过量铁和铜与土壤溶液中 Pvd 的量之间几乎为 1:1 的关系表明，Pvd 通过配体控制溶解主要通过 1:1 的金属-Pvd 络合物来移动铁和铜。生物强化使茎叶中的铜浓度增加了 17%，使根系中的铜浓度增加了 93%，使向日葵茎叶生物量增加了 30%至 60%，导致铜的植物提取量增加了 87%。根和茎叶中的铁、锰、锌和磷的含量也增加了。与预期相反，碳酸化土壤并没有增加 TE 的迁移。我们的结果表明，生物强化增加了植物提取，并且可以通过促进溶液中 Pvd-Cu 络合物在土壤-根界面的解离来进一步提高其性能。
