Abstract Pteris vittata is the most well-known arsenic (As) hyperaccumulator, while the corresponding mechanism in molecular level is still not clear. In this study, As uptake and transport in P. vittata were demonstrated by time-course analyses under As addition. Then expression of 3 genes (PvPht1;3, a phosphate (P) transporter gene; PvACR2, a AsV reductase gene; PvACR3, a AsIII transport gene) was focused on to examine their contributions on As processing in root of P. vittata. Results of As addition analyses revealed that P. vittata had high-sensitivity to even 10 ppb AsV which was quickly depleted within 6 h, while this high affinity was inhibited when coexisting with P. Analyses to As in the plant showed that in the absence of P, 99% of the As taken up by roots was reduced to AsIII at 7 d. And 85% of As transported to rhizomes was present as AsIII, 74% of the As accumulated in fronds was AsIII. Results of qRT-PCR demonstrated that the transcription of PvPht1;3 was temporally induced by 100 ppb AsV without P, while 500 ppb of AsV made this induction kept through the entire period which showed 3.7-fold higher than control at 7 d. Meanwhile, PvACR2 was only induced slightly (1.15-1.45-fold) by 500 ppb AsV with a time lag, and this induction wasn’t infected by P. PvACR3 was induced by 100 ppb AsV immediately, and the strength was positively related to AsV concentration. Intriguingly, the expression of PvACR3 fitted the AsIII concentration in the root. Our results suggested a collaboration of these three genes on sensitive AsV absorption, constitutive AsV reduction and subsequent AsIII transportation which contributes to As hyperaccumulation by P. vittata.

中文翻译：

---

PvPht1;3、PvACR2和PvACR3在紫檀根处理砷过程中的表达

摘要 Pteris vittata 是最著名的砷（As）超富集植物，但在分子水平上的相应机制尚不清楚。在这项研究中，通过添加 As 下的时间过程分析证明了 P. vittata 中的 As 吸收和运输。然后重点关注 3 个基因（PvPht1；3，磷酸 (P) 转运蛋白基因；PvACR2，AsV 还原酶基因；PvACR3，AsIII 转运基因）的表达，以检查它们对 P. vitata 根中 As 加工的贡献。As 添加分析的结果显示，P. vittata 对甚至 10 ppb 的 AsV 具有高灵敏度，在 6 小时内迅速耗尽，而当与 P. 共存时，这种高亲和力受到抑制。 对植物中 As 的分析表明，在没有P, 99% 的被根吸收的 As 在第 7 天被还原为 AsIII。运输到根茎的砷有 85% 以 AsIII 的形式存在，叶中积累的砷有 74% 以 AsIII 的形式存在。qRT-PCR 的结果表明 PvPht1;3 的转录被 100 ppb 无 P 的 AsV 暂时诱导，而 500 ppb 的 AsV 使这种诱导保持在整个时期，在第 7 天显示比对照高 3.7 倍。同时，PvACR2仅被500 ppb AsV轻微诱导（1.15-1.45倍）并具有时滞性，且该诱导未被PvACR感染。PvACR3立即被100 ppb AsV诱导，强度与AsV呈正相关专注。有趣的是，PvACR3 的表达符合根中 AsIII 的浓度。我们的结果表明这三个基因在敏感的 AsV 吸收上的协作，