Table 3.

Functional characterization of WRKYs towards salt stress and associated mechanism.

Plant system	Type of WRKY protein	Response to salinity	Biochemical and physiological changes	References
Arabidopsis thaliana	AtWRKY33	Enhances salinity tolerance in transgenic Arabidopsis thaliana	Improved stress tolerance via increased seedling length, reduced oxidative stress, as well as by preventing leaf chlorosis.	Jiang and Deyholos (2009)
Brassica campestris	BcWRKY46	Enhanced salinity tolerance in transgenic Nicotiana tabacum	Enhanced stress tolerance by increasing seed germination, mediated signal transduction, as well as by activating the expression of osmotic stress genes.	Wang et al. (2012a)
Dendronthemagrandiform	DgWRKY5	Improved salinity tolerance in transgenic Dendronthema grandiform.	Improved stress tolerance via improvements to a number of growth characteristics, including root length, chlorophyll content, fresh weight, and leaf gas exchange parameters as well as by reduced oxidative stress via upregulating the activity of antioxidant enzymes as well as the expression of genes associated with stress.	Liang et al. (2017)
Fagopyrumtataricum	FtWRKY46	Enhanced salinity stress tolerance in transgenic Arabidopsis thaliana	Enhanced stress tolerance by modulating the ROS clearance as well as the expression of stress-responsive genes.	Lv et al. (2020)
Glycine max	GmWRKY49	Improved salinity stress tolerance in transgenic Glycine max and Arabidopsis thaliana	Enhanced stress tolerance by improving several growth parameters like germination rate, root length, survival rate, and rosette diameter by reducing oxidative stress as well by regulating downstream stress-responsive genes.	Xu et al. (2018)
Glycine max	GmWRKY12	Confers salt tolerance in transgenic Glycine max	It confers salt stress tolerance by lowering oxidative stress, as evidenced by higher proline content and lower malondialdehyde (MDA) content in transgenic lines	Shi et al. (2018)
Glycine max	GmWRKY54	Improved salinity stress tolerance in transgenic Glycine max	Improved stress tolerance via regulated DREB2A and STZ/Zat10.	Zhou et al. (2008)
Gossypium hirsutum	GhWRKY68	Reduced salinity tolerance in transgenic Gossypium hirsutum	Sensitive to oxidative stress.	Jia et al. (2015)
Gossypium hirsutum	GhWRKY17	Reduced salt tolerance	The transgenic Nicotiana benthamiana overexpressing Gh WRKY17 exhibited impaired stomatal closer and also modulate the antioxidant defense mechanism.	Yan et al. (2014)
Ipomoea batatas L.	IbWRKY2	Increased salinity stress tolerance in transgenic Arabidopsis thaliana	Increased stress tolerance via reduced oxidative stress by increasing gene expression, associated with the ABA signaling pathway, proline biosynthesis, and ROS-scavenging system	Zhu et al. (2020)
Jatropha curca	JcWRKY	Improved salt stress tolerance in transgenic Nicotianata tabacum L.	Improved stress tolerance via improvement in several growth parameters such as increasing germination potential, membrane stability, as well as by reducing oxidative stress via improved activity of antioxidant enzymes.	Agarwal et al. (2016)
Malus baccata (L.) Borkh	MbWRKY5	Increases salinity tolerance in transgenic N. tabacum var. Xanthi	Increased stress tolerance by reducing oxidative stress via improving activity of antioxidant enzymes as well as increased expression of stress-responsive genes.	Han et al. (2018)
Malus domestica	MdWRKY30	Improved salinity stress tolerance in transgenic Arabidopsis thaliana.	Improved stress tolerance via transcriptional regulation of stress-related genes.	Dong et al. (2020)
Malus domestica	MdWRKY100	Enhances salinity tolerance in transgenic Malus domestica	Improved stress tolerance via reduced oxidative stress.	Ma et al. (2021)
Malus xiaojinensis	MxWRKY55	Improved salinity tolerance in transgenic Arabidopsis thaliana	It enhances tolerance to stress by increasing proline and chlorophyll content. Improving the antioxidant defense system, which reduced malondialdehyde content	Han et al. (2020)
Oryza sativa	OsWRKY72	Increased susceptibility to salinity stress in transgenic Arabidopsis thaliana and salt sensitivity in Oryza sativa.	Exogenous application of ABA and NaCl induced OsWRKY72 expression in rice under salinity stress and improved the salt tolerance in rice by upregulation of OsWRKY72	Song et al. (2010)
Pennisetum glaucum	PgWRKY33/62	It enhances salt tolerance in pearl millet	PgWRKY62 was significantly unregulated in salt-treated pearl millet plants. Differential expression pattern in response to salinity stress in various tissue such as leaf, stem, and root.	Chanwala et al. (2020)
Phyllostachys edulis	PeWRKY83	Enhanced salinity stress tolerance in transgenic Arabidopsis thaliana	It improves stress tolerance by regulating the stress-induced synthesis of ABA.	Wu et al. (2017)
Populus alba	PagWRKY75	Negatively regulate salt stress in Populus alba	PagWRKY75 reduces the ROS scavenging ability and proline accumulation under various stresses, and positively regulates the water loss rate of leaves. Thus, PagWRKY75 can negatively regulate salt and osmotic tolerance by altering various physiological processes.	Zhao et al. (2019)
Solanum lycopersicum L.	SlWRKY8	Mediates salt stress tolerance in transgenic S. lycopersicum L.	Mediate salinity stress tolerance by reducing oxidative stress via increased activity of antioxidant enzymes.	Gao et al. (2020)
Triticum aestivum L.	TaWRKY2/19	Improved salinity tolerance in transgenic wheat	Improved stress tolerance by regulating downstream stress-responsive genes.	Niu et al. (2012)
Triticum aestivum L.	TaWRKY93	Enhanced salinity stress tolerance in transgenic Arabidopsis thaliana	It enhances salinity tolerance by enhancing osmotic adjustment, and regulates transcription of stress-responsive genes.	Qin et al. (2015)
Vitis pseudoreticulata	VpWRKY3	Improves salinity tolerance in transgenic N. tabacum	VpWRKY3 is involved in abscisic acid signal pathway.	Zhu et al. (2012)
Vitis vinifera	VvWRKY30	Improves salinity tolerance in transgenic Arabidopsis thaliana	Controlling the scavenging of reactive oxygen species as well as accumulating osmoprotectants.	Zhu et al. (2019)
Zea mays	ZmWRKY17	Increased susceptibility to salinity stress in transgenic A. thaliana	Increased susceptibility to salinity stress via regulation of stress-responsive genes.	Cai et al. (2017)