ISPA, Bordeaux Sciences Agro, INRA, 33140, Villenave d'Ornon, France.
ISPA, Bordeaux Sciences Agro, INRA, 33140, Villenave d'Ornon, France; LPG, UMR 6112 CNRS-Université de Nantes, BP 92208, 44322, Nantes, Cedex 3, France.
Chemosphere. 2019 Dec;236:124347. doi: 10.1016/j.chemosphere.2019.124347. Epub 2019 Jul 10.
Pyoverdine (Pvd) is a bacterial siderophore produced by some Pseudomonads species that can bind copper in addition to iron in soil. Pvd is expected to alter the dynamics and the ecotoxicity of Cu in vineyard soils. This study investigated the extent to which the mobility and the phytoavailability of Cu varied among vineyard soils with different pH and how they were affected by a supply of Pvd. Pvd was supplied (or not) to ten vineyard topsoils with pH ranging from 5.9 to 8.6 before metal was extracted with 0.005 M CaCl. Cu mobility was assessed through its total concentration and Cu phytoavailability through its free ionic concentration measured in the CaCl extract. Cu mobility varied by a factor of six and Cu phytoavailability by a factor of 5000 among the soil samples. In the CaCl extract, the concentration of Cu was not correlated with the concentration of total Cu but was correlated with pH. This revealed that Cu phytoavailability depends to a great extent on Cu complexation in soil pore water, the latter being highly sensitive to pH. Adding Pvd enhanced the mobility of Cu in the soils including in carbonate soils. The Pvd-mobilization factor for Cu varied from 1.4 to 8 among soils, linked to the availability of Fe and Al in the solid phase and to Pvd partitioning between the solid and the liquid phase. Adding Pvd reduced the concentration of Cu in CaCl extract, which challenges the idea of using Pvd-producing bacteria to promote Cu phytoextraction.
绿脓菌素（Pvd）是某些假单胞菌属产生的细菌铁载体，除了能结合土壤中的铁以外，还能结合铜。Pvd 有望改变葡萄园土壤中铜的动态和生态毒性。本研究调查了不同 pH 值的葡萄园土壤中铜的迁移率和植物可利用性的差异程度，以及 Pvd 的供应如何影响这些差异。在将金属用 0.005 M CaCl 提取之前，向 pH 值范围为 5.9 至 8.6 的十个葡萄园表土中添加或不添加 Pvd。通过测定 CaCl 提取物中的总浓度来评估 Cu 的迁移率，通过测定 CaCl 提取物中的游离离子浓度来评估 Cu 的植物可利用性。Cu 的迁移率在土壤样品之间变化了六个数量级，Cu 的植物可利用性变化了 5000 倍。在 CaCl 提取物中，Cu 的浓度与总 Cu 的浓度无关，而是与 pH 有关。这表明 Cu 的植物可利用性在很大程度上取决于土壤孔隙水中 Cu 的络合，而后者对 pH 非常敏感。添加 Pvd 增强了 Cu 在土壤中的迁移性，包括在碳酸盐土壤中的迁移性。Cu 的 Pvd 迁移因子在土壤之间变化范围为 1.4 至 8，与固相中的 Fe 和 Al 的可用性以及 Pvd 在固相与液相之间的分配有关。添加 Pvd 降低了 CaCl 提取物中 Cu 的浓度，这对使用产生 Pvd 的细菌来促进 Cu 植物提取的想法提出了挑战。
