Phosphorus mediated rhizosphere mobilization and apoplast precipitation regulate rare earth element accumulation in Phytolacca americana
Phosphorus mediated rhizosphere mobilization and apoplast precipitation regulate rare earth element accumulation in Phytolacca americana
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DOI：
10.1007/s11104-022-05743-4
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发表时间：
2022-10-17
期刊：
影响因子：
4.9
通讯作者：
Qiu, Rong-Liang
中科院分区：
文献类型：
--
作者：
Liu, Chong;Ding, Ting-Xuan;Qiu, Rong-Liang
目的植物有效磷(P)被认为是影响超积累植物商陆(Phytolacca Americana)对稀土元素(REE)积累的主要土壤因子，但其内在机制尚不清楚。方法采用土壤磷改良法和外源有机酸添加试验，研究了磷胁迫下美洲对虾土壤化学性质的变化及其对稀土元素积累的影响。在水培条件下，还进行了P和REE浓度的调控，并分析了P和REE从根到地的运转。结果缺磷导致根际pH(0.8单位)下降和有机酸的分泌，从而促进了磷和稀土的动员，最终增加了美洲大闸藻对稀土元素的积累。然而，土壤磷供应的增加减少了90%的稀土元素在地上部的积累。在1~10mU/m ol的L-1Y处理下，喷施磷不影响美洲大麦体内Y(Y)的积累，但在100mU/m ol的L-1Y处理下，限制了Y(Y)从根到地的运转。此外，与1MU的L-1Y处理相比，100MU的L-1Y处理下，根部磷浓度增加近两倍，并有更多的磷分配到质外体。水培美洲大白杨根部Y、P浓度的线性回归斜率为3.4，接近YPO4沉淀物的Y/P比值(2.9)。结论P介导的根际REE动员和内质外体沉淀可以调节美洲大闸藻REE的积累。
Aims The plant available phosphorus (P) is deemed as the main soil factor affecting the accumulation of rare earth elements (REEs) in the hyperaccumulator plant Phytolacca americana, but the underlying mechanisms are largely unknown. Methods Soil P amendment and exogenous organic acids addition experiments were employed to determinate the P-induced soil chemical properties changes and subsequent REE accumulation variations in P. americana. Manipulations of P and REE concentration were also conducted under hydroponic conditions, and the translocation of P and REE from roots to shoots was analyzed. Results P-deficiency induced a decrease of pH (0.8 unit) and secretion of organic acids in the rhizosphere, thus contributing to the mobilization of P and REEs, and the increased REE accumulation in P. americana eventually. However, an elevated soil P supply reduced REE accumulation by 90% in shoots. P spray did not affect the accumulation of yttrium (Y) in P. americana under 1-10 mu mol L-1 Y treatment, but limited Y translocation from roots to shoots under 100 mu mol L-1 Y treatment. Moreover, compared to 1 mu mol L-1 Y treatment, under 100 mu mol L-1 Y the root P concentration was nearly tripled and more P was allocated to the apoplast. The linear regression slope between Y and P concentrations in the roots of hydroponic P. americana was 3.4, being close to the Y/P ratio of YPO4 precipitates (2.9). Conclusions Our study demonstrates that P mediated REE mobilization in the rhizosphere and apoplast precipitation within the endosphere can regulate the REE accumulation in P. americana.