Transgenic expression of TaGR2-D provides drought and salinity tolerance in Arabidopsis

Glutathione reductase (GR) belongs to the ascorbate-glutathione cycle and reduces oxidised glutathione (GSSG) to reduced glutathione (GSH), hence contributing to redox equilibrium maintenance in the plant cells. It is accountable for scavenging the excessive generation of reactive oxygen species (ROS), thereby helping in oxidative stress management. In this study, we demonstrated the improved morpho-physio-biochemical characteristics in TaGR2-D expressing transgenic Arabidopsis lines during drought and salt stress, highlighting its role in stress tolerance. The transgenic lines showed improved seed germination, root growth, and morphological traits like rosette area and leaf parameters including length, width, and leaf area index. The biochemical parameter such as proline utilised as stress marker, was higher in transgenics than in wild-type (WT). The malondialdehyde and hydrogen peroxide accumulations were lesser in transgenics than in WT plants, which signifies lesser lipid peroxidation and ROS production in transgenic plants. Transgenic lines showed improvement in physiological parameters such as chlorophyll pigments, carotenoids contents, relative electrical conductivity and relative water content. TaGR2-D expression also modulates the enzymatic antioxidant activities and the glutathione and ascorbate pools, thereby mitigating oxidative stress generated during drought and salinity stress. The present work established the function of TaGR2-D in providing drought and salt stress tolerance.