Table 2.

List of genetically modified plant-associated microbes for heavy metal stress tolerance (based on Ullah et al., 2015).

S. No.	Genetically engineered microbe	Modified gene expression	Associated plant	Heavy metal(s)	Reference
1.	Pseudomonas putida	Phytochelatin synthase	Triticum aestivum	Cd, Hg, Ag	Yong et al., 2014
2.	Mesorhizobium huakuii	Metallothionein, phytochelatin synthase	Astragalus sinicus	Cd, Cu, Zn, As	Ike et al., 2008
3.	Mesorhizobium huakuii	Metallothionein, phytochelatin synthase	Astragalus sinicus	Cd	Ike et al., 2007
4.	Pseudomonas putida	Expression of metal binding peptide	Helianthus annuus	Cd	Wu et al., 2006
5.	Mesorhizobium huakuii	Phytochelatin synthase	Astragalus sinicus	Cd	Sriprang et al., 2003
6.	Meshorhizobium huakuii	Metallothionein	Astragalus sinicus	Cd	Sriprang et al., 2002
7.	Enterobacter cloacae	EC 4.1.99.4	Brassica napus	As	Nie et al., 2002
8.	Ralstonia eutropha	Metallothionein	Nicotiana benthamiana	Cd	Valls et al., 2000