Molecular characterization of late embryogenesis abundant proteins encoding genes from wild sorghum genotype IS-18,909 expressed under drought stress

As a drought-tolerant crop, sorghum is an ideal plant for identifying genes conferring drought tolerance. In the present study, LEA1 and LEA 3 genes expressing in response to PEG-6000 induced osmotic stress were isolated from drought and heat tolerant wild sorghum genotype IS-18,909. Gene-specific primers were designed and used for cDNA synthesis of late embryogenesis abundant (LEA) proteins encoding LEA1 (547 bp) and LEA3 (817 bp) genes. Sequence analysis of LEA1 (547 bp) and LEA3 (817 bp) cDNA confirmed the presence of corresponding full-length coding sequences. LEA1 and LEA3 proteins had specific 20 nucleotides and 11 nucleotides consensus sequences, respectively, and other conserved sequences. These drought-induced proteins are extremely hydrophilic, resistant to dehydration, and high in amino acid residues with the sulfhydryl group (serine, threonine). They are composed largely of the amino acids glycine, alanine, and glutamine and lack cysteine and tryptophan. The genes conferring drought tolerance may provide a foundation for improving sorghum productivity under water deficit conditions.