Abstract

Abstract

The present invention provides nucleic acid sequences encoding a metal ion resistance protein, which are expressible in plant cells. The metal resistance protein provides for the enzymatic reduction of metal ions including by not limited to divalent Cu, divalent mercury, trivalent gold, divalent cadmium, lead ions and monovalent silver ions. Transgenic plants which express these coding sequences exhibit increased resistance to metal ions in the environment as compared with plants which have not been so genetically modified. Transgenic plants which are resistant to organomercurials including alkylmercury compounds, among others, are provided by the further inclusion of plant-expressible organomercurial lyase coding sequences. Furthermore, these transgenic plants which have been genetically modified to express the metal resistance coding sequences of the present invention can participate in the bioremediation of metal contamination via the enzymatic reduction of metal ions. Transgenic plants resistant to organomercurials can further mediate remediation of alkylmercury compounds in the environment by causing the freeing of mercuric ions and the reduction of the ionic mercury to the less toxic elemental mercury.