Arsenic (As) contamination in soil poses a potential threat to human health via crop uptake. As-hyperaccumulator Pteris vittata serves as a model plant to study As uptake and associated mechanisms. This study focuses on a novel P/AsV transport system mediated by low-affinity phosphate transporter-B 1 family (PTB1) in P. vittata. Here, we identified two plasma-membrane-localized PTB1 genes, PvPTB1;1/1;2, in vascular plants for the first time, which were 4.4–40-fold greater in expression in P. vittata than in other Pteris ferns. Functional complementation of a yeast P-uptake mutant and enhanced P accumulation in transgenic Arabidopsis thaliana confirmed their role in P uptake. Moreover, the expression of PvPTB1;1/1;2 facilitated the transport and accumulation of As in both yeast and A. thaliana shoots, demonstrating a comparable AsV uptake capacity. Microdissection-qPCR analysis and single-cell transcriptome analysis collectively suggest that PvPTB1;1/1;2 are specifically expressed in the epidermal cells of P. vittata roots. PTB1 may play a pivotal role in efficient P recycling during phytate secretion and hydrolysis in P. vittata roots. In summary, the dual P transport mechanisms consisting of high-affinity Pht1 and low-affinity PTB1 may have contributed to the efficient P/As uptake in P. vittata, thereby contributing to efficient phytoremediation for As-contaminated soils.

中文翻译：

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新型磷酸盐转运蛋白-B PvPTB1;1/1;2 有助于高富集植物 Pteris vittata 的有效磷酸盐吸收和砷积累

土壤中的砷（As）污染通过农作物的吸收对人类健康构成潜在威胁。 As 超富集植物Pteris vittata作为模型植物来研究 As 吸收和相关机制。本研究重点关注P. vittata中由低亲和力磷酸盐转运蛋白 B 1 家族 (PTB1) 介导的新型 P/AsV 转运系统。在这里，我们首次在维管植物中鉴定出两个质膜定位的PTB1基因PvPTB1;1/1;2 ，其在P. vittata中的表达量比其他凤尾蕨类植物高 4.4-40 倍。酵母磷吸收突变体的功能互补和转基因拟南芥中磷积累的增强证实了它们在磷吸收中的作用。此外， PvPTB1;1/1;2的表达促进了酵母和拟南芥芽中 As 的转运和积累，表现出相当的 AsV 吸收能力。显微切割-qPCR 分析和单细胞转录组分析共同表明PvPTB1;1/1;2在P. vittata根的表皮细胞中特异性表达。 PTB1 可能在P. vittata根植酸分泌和水解过程中的有效磷回收中发挥关键作用。综上所述，由高亲和力Pht1和低亲和力PTB1组成的双磷转运机制可能有助于P. vittata对P/As的有效吸收，从而有助于砷污染土壤的有效植物修复。