Analysis of physio-biochemical responses and expressional profiling of DREB transcription factors for drought tolerance in Aegilops tauschii Coss

Aegilops tauschii Coss. (2n = 2x = 14, DD) is a weed that competes with wheat for resources and performs better under various abiotic stresses. It is a valuable genetic material source for wheat crop improvement programs. In this study, greenhouse experiments were conducted to investigate the effects of drought levels on physio-biochemical parameters and expression profiling of the drought-resistant DREB gene. Under different drought levels, the physiological parameters such as plant height, dry weight, biomass, and leaf-related parameters exhibited variations. Moreover, photosynthetic parameters such as maximum and minimum fluorescence and photochemical and non-photochemical quenching were influenced by the different levels of drought stress, and their efficiency was noticed depending on the amount of water availability. Biochemical analysis revealed slight but significant changes in peroxidase, catalase, and proline content, while malondialdehyde exhibited higher variations under different drought stress conditions. In the analysis of DREB gene expression, eight populations of Ae. tauschii exhibited higher expression profiles than the control, i.e., no drought conditions. The expression profiles of Ae. tauschii showed a significant increase under drought conditions compared to the control, and the expression profiles of the DREB gene posed visible changes in correlation with observed variations in physio-biochemical activities.