Table 2.

Example of genes leading to improvement of salt stress tolerance of crop plants through genetic engineering.

Transgene	Function	Donor	Transgenic plant	Description	Reference
Na+/H+ antiporter (AtNHX1)	Vacuolar sequestration of Na+ and K+?	Arabidopsis	Tomato	Enhanced salt tolerance with higher accumulation in leaves but not in fruits	Zhang and Blumwald, 2001
			Brassica napus	Maintenance of seed yield and seed oil quality under high salinity	Zhang et al., 2001
			Wheat	Improved grain yield in saline soils	Xue et al., 2004
			Cotton	Increased fiber yield under salt stress	He et al., 2005
H+-pyrophosphatase (AVP1) AtNHX + AVP1	Vacuolar membrane-bound proton pump	Arabidopsis	Cotton	Increased fiber yield under salt stress in field conditions	Pasapula et al., 2011
			Barley	Higher biomass production and grain yield in saline field	Schilling et al., 2013
			Cotton	Further enhancement of salt tolerance compared to single-gene overexpressing plants	Shen et al., 2014
			Tomato	Increased salt stress tolerance compared to single gene overexpression	Gouiaa and Khoudi, 2015
Ncl	homologous to NHX gene family	Soybean	Soybean	Improved salt tolerance	Do et al., 2016
Mannitol-1-phosphate dehydrogenase mt1D	Mannitol biosynthesis	E. coli	Tobacco	Increased salt tolerance	Tarczynski et al., 1992
Choline synthase codA	Betaine biosynthesis	E. coli	Rice	Enhanced tolerance to salinity and cold	Sakamoto et al., 1998
delta 1-pyrroline-5-carboxylate synthase (P5CS)	Proline biosynthesis	Arabidopsis	Tobacco	Increased tolerance to drought and salt stress	Kishor et al., 1995
ascorbate peroxidase (AtAPX)	ROS-scavenging	Arabidopsis	Tobacco	Enhanced tolerance to salt and osmotic stress	Badawi et al., 2004
Late embryogenesis abundant protein (HVA7)	Osmoprotection	Barley	Rice	Enhanced tolerance to salt and osmotic stress	Xu et al., 1996
Transcription factor DREB1B/CBF1	Transcription regulation	Arabidopsis	Rice	Enhanced tolerance to salinity and drought	Oh et al., 2005
Transcription factor DREB1A/CBF3	Transcription regulation	Arabidopsis	Rice	Increase in salinity tolerance	Hu et al., 2006
SNAC1	Transcription regulation	Rice	Rice	Increase in salinity tolerance	Hu et al., 2008.
Transcription factor SlAREB1	Transcription regulation	Tomato	Tomato	Enhanced tolerance to salinity and water stress	Orellana et al., 2010
Transcription factor ZFP179	Transcription regulation	Rice	Rice	Increase in salinity tolerance	Sun et al., 2010
calcium-dependent protein kinase OsCDPK21	Calcium signaling	Rice	Rice	Increase in salinity tolerance	Asano et al., 2011
MAP kinase GhMPK2	MAPK signaling	Cotton	Tobacco	Enhanced tolerance to salinity and drought	Zhang et al., 2011