Table 1.

ROS-scavenging enzymatic antioxidants and their roles in transgenic rice for abiotic stress tolerance.

Gene	Source	Response	Reference
Superoxide dismutase (SOD)
Cu/Zn SOD	Avicennia marina	Transgenic plants were more tolerant to methyl viologen (MV)-mediated oxidative stress, salinity, and drought stress.	[49]
Mn SOD	Pisum sativum	Electrolyte content declined and less injury observed in leaf discs of transgenic plants compared to that observed in wild type plants following treatment with polyethylene glycol (PEG).	[50]
Mn SOD	Yeast	Transgenic plants maintained high level of SOD and ascorbate peroxidise activity in chloroplast upon exposure to salt stress, while decrease in SOD activities was observed in wild type plants.	[51]
Catalase (CAT)
CAT KatE	E.coli	Transgenic rice plants showed at least 1.5–2.5 fold increase of CAT upon exposure to salt stress. The transgenic rice can survive for another 14 days compared to wild type plants following treatment with salt stress.	[52]
CAT	Triticum aestivum L.	In 5 °C of cold stress, CAT was found 4–15 times higher in transgenic plants compared to that observed in wild type plants with very low levels of H2O2.	[53]
CAT	Suaeda salsa	Co-expression of CAT and GST resulted in the increment of SOD and CAT activities following treatment with salt and paraquat stress, while GST activity only increased upon treatment with paraquat stress. H2O2, malondialdehyde, and electrolyte leakage were found to decrease in transgenic rice compared to wild type plants.	[54]
Ascorbate peroxidase
Knockdown OsAPx1 and OsAPx2	Rice	Compensation of ascorbate peroxidase by other peroxidases, including glutathione peroxidase (GPX).	[55]
OsAPXa	Rice	Transgenic plants maintained H2O2 and malondialdehyde (MDA) content when subjected to cold stress.	[56]
Silencing APx1/2s	Rice	Upregulation of other peroxidases was observed under salinity, heat, high light, and MV treatment.	[55]
Glutathione reductase
GR	Brassica campestris	High expression of GR improved the protection against photo-bleaching of chlorophyll and photo-oxidative action of MV in thylakoid membranes at 25 °C.	[57]
GlutathioneS-transferases
GST	Rice	Seedlings of the transgenic lines grown under submergence demonstrated enhanced germination and growth rates at low temperature.	[58]
OsGSTL1	Rice	The overexpression lines showed an increase in GST and GPX activities, and a decrease in the level of superoxide was observed.	[59]
GST	Suaeda salsa	Salt and paraquat stress tolerance were observed due to GST, CAT, and SOD activity.	[54]