Cloning Of ABC Transporter Genes From Saccharomyce Cerevisiae And Application For Phytoremediation Of Heavy Metals

Environmental pollutions are serious problems facing the whole world and sustainable development. The development of remediation technology for scavenging environmental pollution has become an important research field in recent years. As an environmentally friendly and low-cost remediation technolgy, phytoremediation has gained more and more attention, and phytoremediation via transgenic plants has become a hot spot. Studies have demonstrated that expression of metallothioneins (MTs), phytochelatins (PCs), glutathione (GSH) and transporters in plants can increase the accumulation and/or tolerance to heavy metals. Saccharomyces cerevisiae ABC transporters are a large family and could transport and detoxify the heavy metals. One of the transporters, YCF1, when expressed in plants, has shown to enhance the tolerance and accumulation of some heavy metals such as cadmium, lead, etc. However, the fuctions of other types of the ABC transporters of Saccharomyces cerevisiae need to be elucidated in plants.In this thesis, ten ABC transporter genes were cloned from Saccharomyces cerevisiae, and the plant binary expression vectors were then constructed.The purpose of this study was aimed at the functional comparison of these transporter genes in plants to find efficient transporter genes for heavy metal transport and accumulation. Transgenic tobacco plants expressing these transporters were obtained through the Argobacterium-mediated transformation.The results showed that YCF1 transgene was integrated into tobacco genome, but did not show tolerance toward heavy metals. T0 transgenic plants of some other transporter genes were tested through leaf disc assay, it was demonstrated that some transgenic lines showed increased tolerance toward Cd,Pb,Hg , The molecular analyses, the mechanisms of heavy metal tolerance and the genetic stability of these transgenic lines needs to be further elucidated.