Efficient arsenate reduction in As-hyperaccumulator Pteris vittata are mediated by novel arsenate reductases PvHAC1 and PvHAC2
Efficient arsenate reduction in As-hyperaccumulator Pteris vittata are mediated by novel arsenate reductases PvHAC1 and PvHAC2
复制标题
新型砷酸盐还原酶 PvHAC1 和 PvHAC2 介导砷超富集植物 Pteris vittata 中砷酸盐的有效还原
DOI：
10.1016/j.jhazmat.2020.122895
复制
发表时间：
2020-11-15
影响因子：
13.6
通讯作者：
Ma, Lena Q.
中科院分区：
文献类型：
--
作者：
Li, Xinyuan;Sun, Dan;Ma, Lena Q.
砷超富集植物蜈蚣蕨对砷具有较强的吸收、还原和转运能力。但是，目前关于砷酸盐（AsV）在蜈蚣体内还原的分子机制和作用部位还不清楚。在这里，我们确定了两个新的砷酸还原酶基因，PvHAC1和PvHAC2。两个PvHAC基因编码一个Rhodanaselike蛋白，定位于细胞质和细胞核。重组大肠杆菌菌株和转基因拟南芥系在表达PvHAC基因后均表现出砷酸还原酶能力。此外，表达PvHAC2增强了A.在AsV处理下，表达谱分析表明，PvHAC1和PvHAC2主要在杜仲根茎和叶片中表达。与HAC同源基因在非高穗期的表达不同，PvHAC在根中的表达量很低。此外，在AsV暴露下，PvHAC1表达强烈上调，但AsIII不上调。研究结果表明，黄连根茎中的砷酸盐还原酶PvHAC1与叶中的砷酸盐还原酶PvHAC2在黄连超富集砷过程中发挥了重要作用，这有助于进一步提高黄连对砷污染土壤的植物修复能力。
Arsenic-hyperaccumulator Pteris vittata is efficient in As absorption, reduction, and translocation. But the molecular mechanisms and locations of arsenate (AsV) reduction in P. vittata are still unclear. Here, we identified two new arsenate reductase genes from P. vittata, PvHAC1 and PvHAC2. Two PvHAC genes encoded a rhodanaselike protein, which were localized in the cytoplasm and nucleus. Both recombinant Escherichia coli strains and transgenic Arabidopsis thaliana lines showed arsenate reductase ability after expressing PvHAC genes. Further, expressing PvHAC2 enhanced As tolerance and reduced As accumulation in A. thaliana shoots under AsV exposure. Based on expression pattern analysis, PvHAC1 and PvHAC2 were predominantly expressed in the rhizomes and fronds of P. vittata. Different from those of HAC homologous genes in non-hyperaccumulators, little PvHAC was expressed in the roots. Besides, PvHAC1 expression was strongly upregulated under AsV exposure but not AsIII. The data suggest that arsenate reductase PvHAC1 in the rhizomes coupled with arsenate reductase PvHAC2 in the fronds of P. vittata played a critical role in As-hyperaccumulation by P. vittata, which helps to further improve its utility in phytoremediation of As-contaminated soils.