Both bacteria and yeast in solution have shown to have defense mechanisms against toxic metals such as by actively producing exo-polymers that can can act as ligands or precipitate metal ion. They also, can actively bind ions to cell wall or through ion transport mechanisms to uptake metal ion and compartmentalize within cell system. It should be interesting to see how complex cell system like an agricultural crop deal with Cd ion as a manner of defense against toxicity.  

Most of the Cd is bound to high S ligands

Dear Bilal,

Please have a look at these useful PDF attachments.

Good luck