Isolation and characterization of water-deficit stress-responsive α-expansin 1 () gene from complex.

In this study, full-length (1282-1330 bp) α-expansin 1 () gene from three different accessions belonging to complex (-, - and spp. hybrid-) was isolated using RAGE technique and characterized. The intronic and coding regions of isolated expansin genes ranged between 526-568 and 756-762 bp, respectively. An open reading frame encoding a polypeptide of 252 amino acids was obtained from and commercial sugarcane hybrid, whereas 254 amino acids were obtained in , a wild relative of . Bioinformatics analysis of deduced protein revealed the presence of specific signature sequences and conserved amino acid residues crucial for the functioning of the protein. The predicted physicochemical characterization showed that the protein is stable in nature with instability index (II) value less than 40 and also clearly shown the dominance of random coil in the protein structure. Phylogenetic analysis revealed high conservation of among complex and related crop species, and . The docking study of protein showed the interaction with xylose, which is present in xyloglucan of plant cell wall, elucidated the role of the expansin proteins in plant cell wall modification. This was further supported by the subcellular localization experiment in which it is clearly seen that the expansin protein localizes in the cell wall. Relative expression analysis of gene in complex during drought stress showed high expression of the in comparison with and indicating possible role of in increased water-deficit stress tolerance in . These results suggest the potential use of for increasing the water-deficient stress tolerance levels in crop plants.