Table 1.

Approaches of Fe biofortification of rice: single transgenic approaches

Approach	Introduced genes	Rice cultivar	Cultivation condition	Fold increase in Fe concentration compared to non-transgenic rice a	References
Approach 1	OsGluB1 pro-SoyferH1	Japonica cv. Kitaake	Soil cultivation in greenhouse	2 fold (polished seeds)	Goto et al. 1999
Enhancement of Fe storage in rice seeds by ferritin
				3 fold (brown seeds)
	OsGluB1 pro- SoyferH1b	Japonica cv. Kitaake	Soil cultivation in greenhouse	1.5 fold (brown seeds)	Qu et al. 2005
	OsGlb1 pro-SoyferH1b
	OsGluB1 pro-SoyferH1	Japonica cv. Taipei 309	Soil cultivation in greenhouse	2.2 fold (brown seeds)	Lucca et al. 2002
	OsGluB1 pro-SoyferH1	Indica cv. IR68144	Soil cultivation in greenhouse	3.7 fold (polished seeds)	Vasconcelos et al. 2003
		(High Fe breeder line)
	OsGluA2 pro-OsFer2	Indica cv. Pusa-Sugandh II (Aromatic rice)	Soil cultivation in greenhouse	2.1 fold (polished seeds)	Paul et al. 2012
Approach 2	OsActin1 pro-HvNAS1c	Japonica cv. Tsukinohikari	Soil cultivation in greenhouse	2 fold (polished seeds)	Masuda et al. 2009
Enhancement of Fe translocation by overexpression of NAS
	35S pro-HvNAS1c
	Activation tag line of OsNAS3	Japonica cv. Dongjin	Soil culture in greenhouse	3 fold (polished seeds)	Lee et al. 2009c
	35S pro- OsNAS1, 2, 3	Japonica cv. Nipponbare	Soil cultivation in greenhouse	4 fold (polished seeds)	Johnson et al. 2011
Approach 3	OsSUT1 pro-OsYSL2	Japonica cv. Tsukinohikari	Soil cultivation in greenhouse	4 fold (polished seeds)	Ishimaru et al. 2010
Enhancement of Fe transportation by Fe transporter
Approach 4	Barley IDS3 genome fragment	Japonica cv. Tsukinohikari	Andosol soil in paddy field	1.4 fold (polished seeds) 1.3 fold (brown seeds)	Masuda et al. 2008
Enhancement of Fe uptake and translocation by IDS3 gene
			Calcareous soil in paddy field	1.3 fold (brown seeds)	Suzuki et al. 2008
Approach 5	Ubiquitin pro-OsIRT1	Japonica cv. Dongjin	Paddy field	1.7 fold (leaves)	Lee et al.2009a
Overexpression of Fe transporter				1.1 fold (brown seeds)
	OsActin1 pro-OsYSL15	Japonica cv. Dongjin	Paddy field	1.3 fold (brown seeds)	Lee et al. 2009b
Approach 6	35S pro-OsIRO2	Japonica cv. Tsukinohikari	Calcareous soil in greenhouse	3 fold (brown seeds)	Ogo et al. 2011
Overexpression of transcription factor
Approach 7	OsVIT1 or OsVIT2 T-DNA insertion mutant lines	Japonica cv. Zhonghua11 Japonica cv. Dongjin	Hydroponic culture	1.4 fold (brown seeds)	Zhang et al. 2012
Knockdown of OsVITs genes
			Paddy field	1.4 fold (brown seeds)
	OsVIT2 T-DNA insertion mutant line	Japonica cv. Dongjin	Soil cultivation in greenhouse	1.3 fold (brown seeds)	Bashir et al. 2013
				1.8 fold (polished seeds)

^aThe tissue name written in Parentheses is the rice tissue where Fe concentration was increased. ^bThey introduced these two genes into same transgenic lines. ^c These two genes were introduced separately into rice and they analyzed these two types of transgenic lines.