Isolation and functional validation of stress tolerant gene and its comparative physio-biochemical analysis with transgenic tobacco plants overexpressing and .

MYB transcription factors are one of the most important mediators for the survival of plants under multiple stress responses. In the present study, , encoding a single R3 repeat MYB DNA binding domain was isolated from stress-tolerant wild relative species of sugarcane . In silico analysis of 948 bp coding mRNA sequence of exhibited the presence of four exons and three introns. Further, the gene was transformed in tobacco and its stable inheritance was confirmed through antibiotic resistance screening, PCR amplification and Southern hybridization blotting. Results of the estimation of MDA, proline, total chlorophyll and antioxidant activities of transgenic tobacco lines exhibited least oxidative damage under drought and cold stress over the untransformed ones, the over-expression of has improved drought and cold stress tolerance ability in tobacco. The comparative physiological and biochemical analysis of transgenic tobacco plants overexpressing , and , revealed that the and transgenic plants demonstrated effective tolerance to drought and cold stresses, while showed improved tolerance to salt stress alone. Amongst these three genes, displayed the highest potential for drought and cold stress tolerances as compared to and genes.