Isolation, characterization and expression of an elongation factor 1± gene in potato (Solanum tuberosum) cell cultures

Using a differential display (DDRT-PCR) approach to screen genes involved in response to osmotic stress, we isolated six cDNA clones from potato cell cultures. One of these, clone #54, is a member of the gene family encoding the -subunit of translation elongation factor 1 (EF-1). After sequencing, this clone showed a deduced amino acid sequence of 447 residues. Southern blot analysis revealed that this EF-1 is a member of a family consisting of at least nine genes. The expression of EF-1 increased upon osmotic stress mediated by polyethylene glycol (PEG) but was unaffected by abscisic acid (ABA) treatment. Salt also increased EF-1 expression but with a different kinetics. These results indicate that we cloned an EF-1 in potato which is ABA responsive, independent of osmotic stress. Abbreviations: DDRT-PCR, differential display reverse transcriptase-polymerase chain reaction; PEG, polyethylene glycol; RACE, rapid amplification of cDNA ends; RT-PCR, reverse transcriptase-polymerase chain reaction.