Tamarix hispida metallothionein-like ThMT3, a reactive oxygen species scavenger, increases tolerance against Cd2+, Zn2+, Cu2+, and NaCl in transgenic yeast
Tamarix hispida metallothionein-like ThMT3, a reactive oxygen species scavenger, increases tolerance against Cd2+, Zn2+, Cu2+, and NaCl in transgenic yeast
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DOI：
10.1007/s11033-010-0265-1
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发表时间：
2011-03-01
影响因子：
2.8
通讯作者：
Li, Chenghao
中科院分区：
文献类型：
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作者：
Yang, Jingli;Wang, Yucheng;Li, Chenghao
从刚毛柽柳（Tamarix hispida）叶片cDNA文库中克隆了一个编码3型金属硫蛋白的类金属硫蛋白基因ThMT 3。表达分析表明，ThMT3的mRNA上调高盐度以及重金属离子，和ThMT3主要在叶中表达。表达ThMT 3的转基因酵母（Saccharomyces cerevisiae）对Cd 2+、Zn 2+、Cu 2+和NaCl胁迫的耐受性增强。转基因酵母也积累了更多的Cd 2+，Zn 2+，和NaCl，但没有Cu 2+。分析了4个基因（GLR 1，GTT 2，GSH 1和YCF 1），帮助运输重金属（Cd2+）从细胞质到液泡的表达表明，这些基因都没有诱导下Cd2+，Zn2+，Cu2+，NaCl胁迫在ThMT 3转基因酵母。H2O2水平在转基因酵母在这样的压力条件下，在相同的条件下，在控制酵母的不到一半。在Cd2+、Zn2+、Cu2+和NaCl胁迫下，SOD 1、CAT 1和GPX 1基因在转基因酵母中特异性表达。Cd2+、Zn2+和Cu2+分别增加SOD 1、CAT 1和GPX 1的表达水平，而NaCl诱导SOD 1和GPX 1的表达。
A metallothionein-like gene, ThMT3, encoding a type 3 metallothionein, was isolated from a Tamarix hispida leaf cDNA library. Expression analysis revealed that mRNA of ThMT3 was upregulated by high salinity as well as by heavy metal ions, and that ThMT3 was predominantly expressed in the leaf. Transgenic yeast (Saccharomyces cerevisiae) expressing ThMT3 showed increased tolerance to Cd2+, Zn2+, Cu2+, and NaCl stress. Transgenic yeast also accumulated more Cd2+, Zn2+, and NaCl, but not Cu2+. Analysis of the expression of four genes (GLR1, GTT2, GSH1, and YCF1) that aid in transporting heavy metal (Cd2+) from the cytoplasm to the vacuole demonstrated that none of these genes were induced under Cd2+, Zn2+, Cu2+, and NaCl stress in ThMT3-transgenic yeast. H2O2 levels in transgenic yeast under such stress conditions were less than half those in control yeast under the same conditions. Three antioxidant genes (SOD1, CAT1, and GPX1) were specifically expressed under Cd2+, Zn2+, Cu2+, and NaCl stress in the transgenic yeast. Cd2+, Zn2+, and Cu2+ increased the expression levels of SOD1, CAT1, and GPX1, respectively, whereas NaCl induced the expression of SOD1 and GPX1.