Molecular cloning and characterization of the late embryogenesis abundant group 4 (EgLEA4) gene from oil palm (Elaeis guineensis Jacq)

The Late-Embryogenesis Abundant group 4 (LEA4) genes is a group of genes that have been reported to be involved in stress and hormone responses. The completed LEA4 cDNA sequence was first obtained from a set of EST sequences of oil palm (Elaeis guineensis Jacq), named as EgLEA4. The open reading frame is 486 bp in length, encoding a deduced amino acid sequence of 161 residues with a molecular weight of 16.5 kDa and a pI value of about 8.0. Five amino acid motif patterns were found in the EgLEA4 (II, I, III, IV and V) and each had a close identity to similar LEA4 patterns of soybean (64%).Comparison of the nucleotide sequences of the cDNA and the genomic DNA demonstrated that the EgLEA4 gene is composed of 2 exons and 1 intron. The 52 untranslated region shows a putative promoter sequence involved in the transcription process, drought stress and hormone responsive elements. RT-PCR analysis showed that the EgLEA4 gene was only expressed in mesocarp, during the late stages of fruit development. It also had a higher expression in induced drought conditions indicating that the EgLEA4 protein may be involved in plant adaptation and stress (drought) responsive pathway.