Overexpression of heterotrimeric G protein beta subunit gene (OsRGB1) confers both heat and salinity stress tolerance in rice

• Published in: Plant physiology and biochemistry 2019-11, Vol.144, p.334-344
• Main Authors: Biswas, Sudip, Islam, Md. Nazrul, Sarker, Sarah, Tuteja, Narendra, Seraj, Zeba I.
• Format: Article
• Language: English
• Subjects: Abiotic stress; Gene expression; Gene Expression Regulation, Plant - genetics; Gene Expression Regulation, Plant - physiology; Heat and salinity tolerance; Heterotrimeric G protein beta; Hot Temperature; In planta transformation; Oryza - genetics; Oryza - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Salt Tolerance - genetics; Salt Tolerance - physiology; Stress responsive genes
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2019.10.005

Constitutive overexpression of the rice heterotrimeric G protein beta subunit gene (RGB1) in the commercial rice cultivar BRRI Dhan 55 resulted in improved tolerance to heat or salinity or their combination. Two independently in planta transformed plants with the gene confirmed to be integrated at T2 by Southern hybridization and showing high expression at the T3 seedling stage showed better physiological performance after 8 days in 120 mM salt stress than the wild type. The plants had significantly lower electrolyte leakage and malondialdehyde production, while showing higher levels of chlorophyll. Significantly higher germination at 48 °C or with combined stresses of 42/40 °C day/night stress in the presence of 120 mM salt for 2 days was also observed. Stress responsive genes such as OsAPX1, OsSOD, OsHKT1, OsHSP1, OsHSP2 and OsCOR47 showed higher expression in the RGB1 positive plants. These RGB1 transgenic plants can likely provide a strong defense against climate change. •Rice beta subunit (RGB1) of the G-protein was overexpressed in BRRI Dhan 55 by using in planta transformation method.•The rice was both heat and salt tolerant,whereas the Arabidopsis AGB1 in tobacco was only tolerant to heat.•Several stress responsive genes were enhanced by over-expression of RGB1 in BR55, related to heat and salt stress tolerance.•Physiological characteristics showed that transgenic lines have significantly higher germination rate, root length, shoot length and plant height compared to wild type under heat stress.•Under salt, heat and combined stress, transgenic lines showed lower loss of chlorophyll and electrolytes and low MDA and H2O2 content.