Chin J Plant Ecol ›› 2005, Vol. 29 ›› Issue (4): 659-664.DOI: 10.17521/cjpe.2005.0088

• Research Articles • Previous Articles     Next Articles

IMPROVING HEAVY METAL TOLERANCE OF YEAST BY TRANSFERRING A PHYTOCHELATIN SYNTHASE GENE FROM GARLIC

JIANG Ying-Nan, FENG Bao-Min, ZHANG Hai-Yan, MA Mi()   

  1. Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2004-01-15 Accepted:2004-05-15 Online:2005-01-15 Published:2005-07-31
  • Contact: MA Mi
  • About author:* E-mail: mami@ibcas.ac.cn.
  • Supported by:
    National Natural Science Foundation(30170086);National Natural Science Foundation(30370127);Special Project of Transgenic Research(JY03A2001);Hi-tech R & D Program of China(2001AA645010-5)

Abstract:

Remediation of soils contaminated by heavy metals is one of the most pressing environmental problems 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 isolation and application of the genes from various plant, bacteria, and animal sources that can enhance metal accumulation. Phytochelatin is a type of polypeptide that combines heavy metals in plants, and its synthesis is regulated by phytochelatin synthesase (PC synthase). In this study, we determined that the roots of garlic (Allium sativum) can accumulate up to 3 000 mg·kg-1 cadmium. A yeast-expressed plasmid with PC synthesase from garlic (AsPCS) was constructed and transferred into heavy metal sensitive yeast mutant cells. The results showed that the expression of AsPCS was improved by 4 folds in yeast cells with cadmium tolerance and a 2 folds increase was observed in arsenate tolerant cells as compared to the control cells. Further study about the growth patterns of AsPCS-expressed yeast indicated that the expression of AsPCS was critical for yeast heavy metal tolerance. As an important role in the garlic's response to heavy metal, AsPCS can work as a significant gene tool in the phytoremediation of heavy metal pollution.

Key words: Phytochelatin synthase gene, Phytoremediation, Heavy metal tolerance, Garlic