TABLE 7.

Role of melatonin in inducing stress tolerance in transgenic plant species.

Crop species	Genes	Stress	Characteristics	References
Tomato	SlCOMT1	Salt stress	The over-expression of SlCOMT1 genes enhanced the crop growth, biomass production, proline contents and reduced the H2O2 contents by increasing the activities of SOD	Liu et al., 2019
Alfalfa	MsSNAT	Cadmium stress	The increase in expression of MsSNAT increased the endogenous MT, root length, chlorophyll contents and decreased the H2O2 accumulation Cd accumulation in plant roots	Gu et al., 2017
Switch grass	oAANAT; oHIOMT	Salt stress	The increase in genes expression increased the plant height, stress growth, proline contents, leaf water status, and decreased MDA accumulation, electrolyte leakage, and Na+ accumulation	Huang et al., 2017
Tomato	oHIOMT	Drought stress	The overexpression of oHIOMT increased the drought tolerance and decreased the leaf wilting and dehydration rate	Wang et al., 2014
Tobacco	MzASMT 1	Salt stress	The over-expression of the MzASMT 1 gene increased the MT contents, plant height, biomass production, leaf water status, chlorophyll contents, proline accumulation, and reduced the MDA contents by increasing activities of anti-oxidants	Zhuang et al., 2020
Arabidopsis	TaCOMT	Drought stress	Over-expression of TaCOMT increased GA and IAA accumulation, decreased ABA accumulation, increased endogenous MT accumulation	Yang et al., 2019
Arabidopsis	VvSNAT1	Salt tolerance	The over-expression of VvSNAT1 increased the endogenous MT contents, reduced leaf wilting, increased germination and biomass production, and decreased the MDA and H2O2 accumulation	Wu et al., 2021b