Expression of FIHMA3, a P1B2-ATPase from Festulolium loliaceum, correlates with response to cadmium stress
Expression of FIHMA3, a P1B2-ATPase from Festulolium loliaceum, correlates with response to cadmium stress
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DOI：
10.1016/j.plaphy.2017.01.013
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发表时间：
2017-03-01
影响因子：
6.5
通讯作者：
Mur, Luis A. J.
中科院分区：
文献类型：
--
作者：
Guo, Qiang;Meng, Lin;Mur, Luis A. J.
重金属ATPase 3(HMA3)是一种P-IB2-ATPase，是一种重要的液泡膜转运体，参与介导镉(Cd)的液泡滞留，从而解毒植物对该元素的吸收。HMA3在杂交种高羊茅(Festulolium loliaceum(Huds.)P.Fourn.本研究发现FIHMA3由833个氨基酸残基组成，与水稻OsHMA3的同源性为77%。融合增强绿色荧光蛋白的FIHMA3在拟南芥原生质体中的瞬时表达表明其定位于液泡膜。实时荧光定量RT-PCR分析表明，FIHMA3主要在根中表达，并受过量Cd的上调。在168h的处理过程中，无论外界的氯化镉浓度如何，莲子草根中的Cd含量均显著高于地上部。FIHMA3的表达与10-100 mg L-1CdCl2处理168h，或25或100 mg I：1CdCl2处理168h的F loliaceum幼苗根系Cd积累呈显著正相关。这些发现为FIHMA3编码一个液泡型P-1b2-ATPase提供了证据，该酶可能在Cd~(2+)固存到根细胞液泡中发挥重要作用，从而限制Cd~(2+)进入细胞质，从而降低Cd~(2+)的毒性。(C)2017年爱思唯尔·马森公司。版权所有。
Heavy metal ATPase 3 (HMA3), a P-IB2-ATPase, is a key tonoplast transporter involved in mediating the vacuolar sequestration of cadmium (Cd) to detoxify the intake of this element by plants. HMA3 expression in response to Cd stress has not been previously examined in the grass hybrid species Festulolium loliaceum (Huds.) P. Fourn. In this study, FIHMA3 isolated from F loliaceum was found to comprise 833 amino acid residues with 77% homology to the rice OsHMA3. Transient expression of FIHMA3 fused to enhanced green fluorescent protein in Arabidopsis protoplasts suggested its localization to vacuolar membranes. Quantitative real-time RT-PCR analysis of F loliaceum revealed that FIHMA3 is expressed predominantly within roots and up-regulated by excess Cd. Over the 168 h treatment, Cd content of F. loliaceum roots was significantly higher than that of shoots, regardless of external CdCl2 concentrations. A significant positive correlation was found between FIHMA3 expression and Cd accumulation in roots of F loliaceum seedlings subjected to 10-100 mg L-1 CdCl2 for 168 h or, in a separate experiment, to 25 or 100 mg I:1 CdCl2 for the same duration. These findings provide evidence that FIHMA3 encodes a vacuolar P-1B2-ATPase that may play an important role in Cd2+ sequestration into root cell vacuoles, thereby limiting the entry of Cd2+ into the cytoplasm and reducing Cd2+ toxicity. (C) 2017 Elsevier Masson SAS. All rights reserved.