IMPROVING HEAVY METAL TOLERANCE OF YEAST BY TRANSFERRING A PHYTOCHELATIN SYNTHASE GENE FROM GARLIC
大蒜植物络合素合酶基因转化对酵母重金属抗性的提高

Remediation of soils contaminated by heavy metals is one of the most pressing environmental prob-lems facing the biosphere. Phytoremediation is a new biotechnique to clean environmental pollutants by plants,including heavy metals. In the long term, major improvements in phytoremediation will rely on the isolationand application of the genes from various plant, bacteria, and animal sources that can enhance metal accumu-lation. Phytochelatin is a type of polypeptide that combines heavy metals in plants, and its synthesis is regulat-ed by phytochelatin synthesase (PC synthase). In this study, we determined that the roots of garlic (Alliumgarlic (AsPCS) was constructed and transferred into heavy metal sensitive yeast mutant cells. The resultsshowed that the expression of AsPCS was improved by 4 folds in yeast cells with cadmium tolerance and a 2folds increase was observed in arsenate tolerant cells as compared to the control cells. Further study about thegrowth patterns of AsPCS-expressed yeast indicated that the expression of AsPCS was critical for yeast heavymetal tolerance. As an important role in the garlic' s response to heavy metal, AsPCS can work as a significantgene tool in the phytoremediation of heavy metal pollution.