Expression of New Pteris vittata Phosphate Transporter PvPht1;4 Reduces Arsenic Translocation from the Roots to Shoots in Tobacco Plants
Expression of New Pteris vittata Phosphate Transporter PvPht1;4 Reduces Arsenic Translocation from the Roots to Shoots in Tobacco Plants
复制标题
新凤尾蕨磷酸盐转运蛋白 PvPht1;4 的表达减少了烟草植物中砷从根到芽的转运
DOI：
10.1021/acs.est.9b05486
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发表时间：
2020-01-21
影响因子：
11.4
通讯作者：
Ma, Lena Q.
中科院分区：
文献类型：
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作者：
Sun, Dan;Feng, Huayuan;Ma, Lena Q.
砷-超蓄积体Pteris vittata可能通过磷酸盐转运体（Pht）有效吸收砷。在这里，我们第一次克隆了一个新的PvPht1；研究了该基因在酵母和转基因烟草对砷酸盐（AsV）的吸收和转运中的作用。基于实时定量聚合酶链反应（qRT-PCR）， PvPht1；4在维塔叶片和根中大量表达，其在根中的转录本受缺磷和砷的双重诱导。PvPht1;4定位于质膜，弥补了酵母突变体对磷吸收缺陷，比PvPht1具有更高的磷转运亲和力；AsV暴露下，PvPht1；4个酵母转化子表现出与PvPht1相当的耐受性；3，但As积累量高于PvPht1；2个变压器，表示PvPht1；4株有相当大的AsV和P转运活性。而在土壤和水培试验中，PvPht1；4个表达烟草系的茎部累积砷含量比野生型植株低26-44和37-55%，根系到茎部的砷转运也较低。在PvPht1的根；4个品系的谷胱甘肽（GSH）含量和GSH合成酶基因NtGSH2的表达量均较高。此外，PvPht1中AsIII-GSH转运体NtABCC1的转录本；4株表达上调。数据显示PvPht1；4个品系可能通过将AsV还原为AsIII来解毒，AsIII与GSH复合物储存在根液泡中，从而减少了转基因烟草中As的易位。鉴于其强大的AsV转运能力，PvPht1的表达；4为减少植物枝条中砷的积累提供了新的分子途径。
Arsenic-hyperaccumulator Pteris vittata is efficient in As uptake, probably through phosphate transporters (Pht). Here, for the first time, we cloned a new PvPht1;4 gene from P. vittata and investigated its role in arsenate (AsV) uptake and transport in yeast and transgenic tobacco plants. On the basis of quantitative real-time polymerase chain reaction (qRT-PCR), PvPht1;4 was abundantly expressed in P. vittata fronds and roots, with its transcripts in the roots being induced by both P deficiency and As exposure. PvPht1;4 was localized to the plasma membrane, which complemented a yeast-mutant defective in P uptake and showed higher P transport affinity than PvPht1;3. Under AsV exposure, PvPht1;4 yeast transformants showed comparable tolerance as PvPht1;3, but higher As accumulation than PvPht1;2 transformants, indicating that PvPht1;4 had considerable AsV and P transport activity. However, in soil and hydroponic experiments, PvPht1;4 expressing tobacco lines accumulated 26-44 and 37-55% lower As in the shoots than wild type plants, with lower root-to-shoot As translocation. In the roots of PvPht1;4 lines, higher glutathione (GSH) contents and expression levels of GSH synthetase gene NtGSH2 were observed. In addition, the transcripts of AsIII-GSH transporter NtABCC1 in PvPht1;4 lines were upregulated. The data suggested that PvPht1;4 lines probably detoxified As by reducing AsV to AsIII, which was then complexed with GSH and stored in the root vacuoles, thereby reducing As translocation in transgenic tobacco. Given its strong AsV transport capacity, expression of PvPht1;4 provides a new molecular approach to reduce As accumulation in plant shoots.