Cloning and expression analysis of eIF-5A gene in Apocynum venetum

To understand the effects of the eIF-5A gene in response to abiotic stress, the 909 bp full-length cDNA of eIF-5A, including a 480 bp open reading frame encoding 159 amino-acid (aa) residues, was isolated from the leaf of herbal plant (Apocynum venetum) by rapid-amplification of cDNA ends. The deduced molecular weight of the encoding protein was 17.48 kDa with a theoretical pI of 5.61 and predicted no signal peptide. Real-time polymerase chain reaction analysis revealed that AveIF-5A gene expression was induced by cold, salt and drought stress. To determine the biological function of this gene, recombinant plasmids expressing AveIF-5A and AveIF-5A1 (86-156 aa truncated polypeptide) were used to transform Escherichia coli. The analysis of the growth curves of recombinant E. coli revealed that AveIF-5A and AveIF-5A1 improved the resistance of transformed E. coli to low-temperature, drought and salt stress. These results could provide experimental evidence of the function of the AveIF-5A gene as a valuable gene resource in plant resistance-breeding.