CHED 254 |
| It has been observed that plants exposed to soils that are contaminated with heavy metals produce high levels of cysteine-rich metal-binding phytochelatin (PC) peptides. PCs are synthesized from glutathione by phytochelatin synthase. As part of our ongoing investigation into the role of cysteine in metal tolerance, we are investigating the effect of cadmium on the expression of the genes encoding for the enzymes that incorporate cysteine into phytochelatin. Our hypothesis is that metal tolerant plants are able to better meet the demand for phytochelatin than are wild type plants, either by being able to maintain a supply of cysteine for PC synthesis or by more efficient PC synthesis. Cysteine is converted to PC via two intermediates, g-glucys and glutathione, and four enzymes, g-glucys synthase, glutathione synthase, and 2 isoforms of PC synthase. Patterns of expression of the genes for these enzymes is being investigated using RT-PCR and real-time PCR methods on RNA extracted from A. thaliana grown at various levels of cadmium. Quantitative analysis of the extent of expression can provide insight into the use of plants as environmental indicators or as remediation agents in metal-contaminated environments. This research is supported by the NIH, MBRS SCORE S06 GM52588. |
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Undergraduate Research Poster Session: Environmental Chemistry
2:30 PM-4:30 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Poster
Division of Chemical Education |