122
123
Genetic engineering approach has successfully facilitated to alter the biological functions of plants
through modification of primary and secondary metabolism and by adding new phenotypic and
genotypic characters to plants with the aim of understanding and improving their phytoremediation
properties (Davison, 2005).
Metal-hyperaccumulating plants and microbes with unique abilities to tolerate, accumulate and de-
toxifymetals and metalloids, represent an important reservoir of unique genes (Danika, Norman,
2005). These genes could be transferred to fast-growing plant species for enhanced phytoremedia-
tion (De Souza et al., 1998).
Fig. 3. Genetic engineering in phytoremediation
.
The utility of the yeast protein YCF1, a protein which detoxifies Cd by transporting it into
vacuoles has been implemented, for the remediation of Cd and Pb. Transgenic
Arabidopsis thalian-
aplants overexpressing YCF1 showed an enhanced tolerance and accumulated greater amounts of
Cd and Pb. Tolerance and resistance in transgenics improved both for Cd and Pb as desired for ef-
fective phytoremediation (Song et al., 2003).
Brassica juncea was genetically engineered to investigate rate-limiting factors for glutathione and
phytochelatinproduction. To achieve this Escherichia coli gshl gene was introduced. The ECS
transgenic seedlings showed increased tolerance to cadmium and had higher concentrations of phy-
tochelatins, -GluCys, glutathione, and total non proteinthiols compared to wild type seedlings (Ow,
1996).
Достарыңызбен бөлісу: