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Overexpression of StDREB1 Transcription Factor Increases Tolerance to Salt in Transgenic Potato Plants
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International audience. It has been established that drought-responsiveelement binding (DREB) proteins correspond to transcriptionfactors which play important regulatory roles in plant response to abiotic and biotic stresses. In this study, a novel cDNA encoding DREB transcription factor, designatedStDREB1, was isolated from potato (Solanum tuberosum L.). This protein was classified in the A-4 group of DREB subfamily based on multiple sequence alignments and phylogenetic characterization. Semi-quantitativeRT-PCR showed that StDREB1 is expressed in leaves,stems, and roots under stress conditions and it is greatlyinduced by NaCl, drought, low temperature, and abscisicacid (ABA) treatments. Overexpression of StDREB1 cDNAin transgenic potato plants exhibited an improved salt anddrought stress tolerance in comparison to the non-transformed controls. The enhanced stress tolerance may beassociated with the increase in P5CS-RNA expression (d1-pyrroline-5-carboxylate synthetase) and the subsequentaccumulation of proline osmoprotectant in addition to abetter control of water loss. Overexpression of StDREB1also activated stress-responsive genes, such as thoseencoding calcium-dependent protein kinases (CDPKs), intransgenic potatoes under standard and high salt conditions.These data suggest that the StDREB1 transcription factor isinvolved in the regulation of salt stress tolerance in potato by the activation of different downstream gene expression.