Coupling two mercury resistance genes in Eastern cottonwood enhances the processing of organomercury
Coupling two mercury resistance genes in Eastern cottonwood enhances the processing of organomercury
复制标题
DOI：
10.1111/j.1467-7652.2006.00236.x
复制
发表时间：
2007-03-01
影响因子：
13.8
通讯作者：
Merkle, Scott A.
中科院分区：
文献类型：
--
作者：
Lyyra, Satu;Meagher, Richard B.;Merkle, Scott A.
东方白杨(Pillius deltoids Bartr.)前马什。)为了用于汞污染土壤的植物修复，对树木进行了基因工程，以表达MERA(汞离子还原酶)和MerB(有机汞裂解酶)基因。早期对拟南芥和烟草的研究表明，与单独使用merB相比，这种基因组合对有机汞化合物的解毒效果更好，但这两个物种都不是长期田间应用的最佳选择。用携带merB和潮霉素抗性(HptII)基因的根癌农杆菌C58菌株对转新霉素磷酸转移酶(NptII)基因的棉白杨试管苗进行叶盘接种。对选育的叶盘再生芽进行聚合酶链式反应，总的转化率为20%。叶片Western blotting结果显示有MERA和MerB蛋白的表达。汞挥发分析表明，体外培养的MERA/MerB植株对苯基汞具有高度的抗性，有机汞化合物的解毒速度是对照的两到三倍。这表明这些棉白杨是修复有机汞污染场地的合理候选者。
Eastern cottonwood (Populus deltoides Bartr. ex Marsh.) trees were engineered to express merA (mercuric ion reductase) and merB (organomercury lyase) transgenes in order to be used for the phytoremediation of mercury-contaminated soils. Earlier studies with Arabidopsis thaliana and Nicotiana tabacum showed that this gene combination resulted in more efficient detoxification of organomercurial compounds than did merB alone, but neither species is optimal for long-term field applications. Leaf discs from in vitro-grown merA, nptII (neomycin phosphotransferase) transgenic cottonwood plantlets were inoculated with Agrobacterium tumefaciens strain C58 carrying the merB and hygromycin resistance (hptII) genes. Polymerase chain reaction of shoots regenerated from the leaf discs under selection indicated an overall transformation frequency of 20%. Western blotting of leaves showed that MerA and MerB proteins were produced. In vitro-grown merA/merB plants were highly resistant to phenylmercuric acetate, and detoxified organic mercury compounds two to three times more rapidly than did controls, as shown by mercury volatilization assay. This indicates that these cottonwood trees are reasonable candidates for the remediation of organomercury-contaminated sites.