Table 1: Effect of different mer genes, inserted and expressed in different regions of A. thaliana plant, on mercury phytoremediation.

Expression	Inserted gene	Effect on Resistance	References
Cytoplasm	merB	Increase resistance of phenylmercuric acetate PMA to 2 μM	[157].
Cytoplasm	merA	Increase resistance of Hg+2 to 100 Μm	[56].
Cytoplasm	merA/B	Increase resistance of organic and inorganic Hg to 5–10 μM	[158].
Cell membrane	merP (ppk)	Increase resistance of Hg+2 to 10 μM	[159].
Cell membrane	merC	Increase resistance of Hg+2 to 10 μM	[160].
Cytoplasm	merE	Increase of inorganic and organic-Hg accumulation	[55].