Molecular characterization of an MYB transcription factor from a succulent halophyte involved in stress tolerance

Abiotic stresses like drought, salinity and extreme temperature significantly affect crop productivity. Plants respond at molecular, cellular and physiological levels for management of stress tolerance. Functional and regulatory genes play a major role in controlling these abiotic stresses through an intricate network of transcriptional machinery. Transcription factors are potential tools for manipulating stress tolerance since they control a large number of downstream genes. In the present study, we have isolated SbMYB44 from a succulent halophyte, Salicornia brachiata Roxb. SbMYB44 with an open-reading frame of 810 bp encodes a protein of 269 amino acids, with an estimated molecular mass of 30.31 kDa and an isoelectric point of 6.29. The in silico analysis revealed that the SbMYB44 protein contains the conserved R2R3 imperfect repeats, two SANT domains and post-translational modification sites. The SbMYB44 transcript showed up-regulation in response to salinity, desiccation, high temperature, and abscisic acid and salicylic acid treatments. The SbMYB44 recombinant protein showed binding to dehydration-responsive cis-elements (RD22 and MBS-1), suggesting its possible role in stress signalling. Overexpression of SbMYB44 enhanced the growth of yeast cells under both ionic and osmotic stresses.