M. Czako, X. Feng, Y. He, D. Liang, R. Pollock, L. Marton
Genetic manipulation of environmentally important plants can produce elite plant lines with enhanced remediation abilities. Introduction of key genes to increase the remediation ability is an obvious approach and significant progress has been made in recent years in producing genetically modified plants from several species. For improvement of heavy metal accumulation we assembled plant expression cassettes from the fission yeast HMT1 gene but they all failed to express in different plant hosts. Another phytoremediation expression cassette was constructed from the salt marsh worm (Amphitrite ornata) dehaloperoxidase gene and introduced into Arabidopsis and tobacco model systems with more success. Both steady state mRNA and activity have been demonstrated in the transgenic plants. We also have developed a green tissue- (leaf-) specific mercuric reductase (merA) expression cassette using the wheat rbcS promoter to enhance merA expression in fully expanded leaves, decreasing mercury content and enhancing mercury volatilization. We have developed tissue culture methods in our lab for a number of wetland plants of various ecological requirements including Spartina alterniflora. An in vitro mass selection system for elite lines has been developed for several species using the “Liquid Lab Rocker” system of Southern Sun Biosystems (Hodges, SC, USA). Using the 35S and Ubi constitutive promoters controlling the organomercurial lyase (merB) and (merA) genes transgenic Spartina lines were obtained carrying and expressing both genes as indicated by the presence of mRNAs and the resistance to ionic and organic mercury. Gene transfer experiments are in progress with other wetland plants such as Arundo, Phragmites, Typha, and Schoenoplectus species.
Czako, M., Feng, X., He, Y., Liang, D., Pollock, R. and Marton, L. (2006). PHYTOREMEDIATION WITH TRANSGENIC PLANTS. Acta Hortic. 725, 753-770
DOI: 10.17660/ActaHortic.2006.725.105
cell culture, dehaloperoxidase, genetic engineering, mercury, phytoremediation, Spartina alterniflora

Acta Horticulturae