An overexpression of the AP2/ERF transcription factor from Iris typhifolia in Arabidopsis thaliana confers tolerance to salt stress

The roles of ethylene responsive factors (ERFs) and their positive and negative regulations of abiotic stress tolerance have been widely reported. This study reports the characterization of ItERF from Iris typhifolia Kitag with respect to molecular and functional properties. The 867 bp cDNA fragment of ItERF was cloned by reverse transcription PCR from I. typhifolia. Real-time quantitative PCR revealed that ItERF expression was induced in the roots, stems, and leaves of I. typhifolia after NaCl treatment, and that ItERF expressions were significantly higher in the leaves and roots than in the stems. A green fluorescent protein marker revealed that ItERF was located to the nucleus. Plant survival and root growth of ItERF transgenic Arabidopsis thaliana L. seedlings were much better than those of the wild type under NaCl stress. Malondialdehyde content in the transgenic lines was significantly lower than that in the wild type. Growth of yeast transformants showed an enhanced tolerance to salt stress than non-transformed yeast cells. All of the results verified that the expression of ItERF had effects on plant growth under salt stress.