The novel galactosyl transferase-like (SbGalT) gene from Salicornia brachiata maintains photosynthesis and enhances abiotic stress tolerance in transgenic tobacco

• Published in: Gene Vol. 786; p. 145597
• Main Authors: Dubey, Ashish K., Khatri, Kusum, Jha, Bhavanath, Rathore, Mangal S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.06.2021
• Subjects: Abiotic stress; Chenopodiaceae - enzymology; Chenopodiaceae - genetics; Chlorophyll A; Climate-resilience; Cloning, Molecular; Drought; Galactosyltransferases - genetics; Galactosyltransferases - metabolism; Gene Expression Regulation, Plant; Halo-tolerant; Nicotiana - genetics; Nicotiana - physiology; Open Reading Frames; Oxidative damage; Photosynthesis; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - physiology; Reactive Oxygen Species - metabolism; Salinity; Smart-crop and transgenic; Stress, Physiological; Smart-crop and transgenic; ORF; RT; PS; UAP; SVI; Halo-tolerant; Climate-resilience; XTT; Drought; DMF; SFP; RWC; NBT; MSI; DAB; Abiotic stress; Oxidative damage; Salinity; GITC; TI; RH; RACE; ROS; SbGalT
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2021.145597

•A novel Galactosyl transferase-like (SbGalT) gene was characterized form Salicornia brachiata.•SbGalT improved the seed germination and seedling growth in transgenic tobacco under stress.•SbGalT curtailed ROS accumulation and improved responses in transgenic tobacco under stress.•Multivariate data analysis indicated SbGalT as a potential gene to develop smart agriculture. We hereby report in planta function characterization of a novel galactosyl transferase-like (SbGalT) gene from Salicornia brachiata for enhanced abiotic stress tolerance. The SbGalT gene had an open reading frame of 1563 bp. The ectopic expression of SbGalT gene in tobacco improved the seed germination, seedling growth, biomass accumulation and potassium/sodium ratio under salt and osmotic stress. The SbGalT over-expression delayed stress-induced senescence, pigment break-down and ion induced cytotoxicity in tobacco. Higher contents of organic solutes and potassium under stress maintained the osmotic homeostasis and relative water content in tobacco. Higher activity of antioxidant enzymes under stress in transgenic tobacco curtailed the accumulation of reactive oxygen species (ROS) and maintained the membrane integrity. The chlorophyll a fluorescence transient indicated no effects of the imposed strengths of stress on basal state of photosystem (PS) I in transgenic tobacco over-expressing the SbGalT gene. Due to improved membrane integrity, the transgenic tobacco exhibited improved photosynthesis, stomatal conductance, intercellular CO2, transpiration, maximum quantum yield and operating efficiency of PSII, electron transport, photochemical and non-photochemical quenching. In agreement with photosynthesis, physiological health, tolerance index and growth parameters, transgenic tobacco accumulated higher contents of sugar, starch, amino acid, polyphenol and proline under stress conditions. The multivariate data analysis exhibited significant statistical distinctions among osmotic adjustment, physiological health and growth, and photosynthetic responses in control and SbGalT transgenic tobacco under stress conditions. The results strongly indicated novel SbGalT gene as a potential candidate for developing the smart agriculture.