Molecular characterization of the Salicornia brachiata SbMAPKK gene and its expression by abiotic stress.

MAPK cascade is an important intracellular signaling module and function as a convergent point for crosstalk during abiotic stress signaling. In this study SbMAPKK gene has been isolated from Salicornia brachiata, a highly salt tolerant plant growing in costal marshes of Gujarat, India. The SbMAPKK gene is 1,023 bp long, encodes a 340 amino acid protein with an estimated molecular mass of 37.4 kDa. The SbMAPKK shows high sequence identity with NbMKK1 from N. benthamiana, LeMKK4 from Lycopersicon esculentum. SbMAPKK constitutes 11 conserved subdomains of protein kinase. Northern analysis revealed that SbMAPKK transcript expression is induced by different stresses like dehydration, cold and salt, however, maximum expression is observed during cold stress. The phylogenetic analysis and genomic organization confirms that it is an intron less gene belonging 'D' group in MAPKK family.