Yeast Metallothionein in Transgenic Tobacco Promotes Copper Uptake from Contaminated Soils
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- 作者：John C. Thomas ; Elizabeth C. Davies ; Farah K. Malick ; Charles Endreszl ; Chandra R. Williams ; Mohammed Abbas ; Sally Petrella ; Krystal Swisher ; Mike Perron ; Ryan Edwards ; Pam Ostenkowski ; Nicolas Urbanc
- 刊名：Biotechnology Progress
- 出版年：2003
- 出版时间：April 2003
- 年：2003
- 卷：19
- 期：2
- 页码：273 - 280
- 全文大小：179K
- 年卷期：v.19,no.2(April 2003)
- ISSN：1520-6033
文摘
Metallothioneins (MTs) are metal-binding proteins that confer heavy metal toleranceand accumulation in yeast. To augment higher plant metal sequestration, the yeastmetallothionein (CUP 1) was introduced into tobacco plants. The CUP 1 geneexpression and copper and cadmium phytoextraction were determined. To confirmtransformation, selfed and kanamycin-resistant third generation plants were subjectedto DNA blot and polymerase chain reaction (PCR) analysis. A 4 mM CuSO4 stress for7 days resulted in a decline in CUP 1 transcripts versus nonstress conditions. Despitelow mRNA levels, CUP 1 transformants accumulated up to seven times more copperin older versus younger leaves during copper stress. Pooled leaves of transgenic plantsgrown in soils from copper stamp-sands contained two to three times the copper contentas that of the control plants. Unlike some previous reports featuring MT overexpressionin plants, CUP 1 seedlings did not significantly sequester or demonstrate tolerance toCdCl2. Using this transgenic approach, yeast CUP 1 expression under nonstressedconditions contributed to copper metal phytoextraction during a subsequent copperchallenge. This strategy could be incorporated into plants designed for enhancedphytoremediation of metal contaminants.