The StDREB1 transcription factor is involved in oxidative stress response and enhances tolerance to salt stress

Abstract

We have shown previously that the potato dehydration responsive element binding (StDREB1) transcription factor plays an important role in regulating and improving salt and drought stress-response genes in potato plant. To further characterize StDREB1 involvement in stress response, we focuse here on the investigation of the StDREB1 target genes by an Electrophoretic mobility shift assay. The data obtains indicated that the StDREB1 protein can bind to both GCC and DRE boxes in the promoter sequence of target genes, suggesting that this transcription factor may play a key role in the response to abiotic-and biotic-stresses by the activation of the DRE-and GCCmediated signaling pathways. In a second step, since some DREB factors were related to the oxidative stress response, we showed that H 2 O 2 treatment led to a significant increase of StDREB1 expression in wild-type potato plants. Moreover, the analysis of the oxidative stress response of StDREB1 transgenic potato plants revealed lower levels of H 2 O 2 and malondialdehyde than wild-type control plants submitted in vitro to salt stress. An increase in the antioxidant enzyme activities including superoxide dismutase (SOD) and catalase was also observed in StDREB1 plants. In addition, an enhanced expression of the Cu/Zn SOD gene was noticed in these StDREB1 transgenic plants, cultivated under salt stress conditions. These results suggest that StDREB1 plays an essential role in the regulation of stress-response by regulating the oxidative stress response. The involvement of this transcription factor in the activation of osmoprotectant synthesis was also confirmed.

Identification and functional characterization of ten AP2/ERF genes in potato

“…This hypothesis was confirmed in a previous study indicating that the StDREB1 protein can bind to both the GCC and DRE boxes in the promoter sequence of target genes (Bouaziz et al 2015). Moreover, the StDREB1 transgenic potato plants showed improved resistance to F. solani infection (Charfeddine et al 2015a, b).…”

“…Recently, we have shown that StDREB1 plays an essential role in regulation of the oxidative stress response. The involvement of this transcription factor in the activation of osmoprotectant synthesis was also confirmed (Bouaziz et al 2015). These data showed that StDREB1 transcription factor plays an important role in promoting oxidative stress tolerance in potato.…”

“…Moreover, the DNA-binding domain of the DREB factors plays essential roles in the consensus recognition and binding to the DRE cis-element (Sakuma et al 2002;Liu et al 1998). Some DREB factors such as AtDREB2A (Sakuma et al 2002), TINY2 (Wei et al 2005), Tsi1 (Park et al 2001), EgEREBP, (Omidvar et al 2013), BnDREBIII (Liu et al 2006) and StDREB1 (Bouaziz et al 2015) can bind to both GCC and DRE boxes. Sakuma et al (2002) reported the identification of 56 genes coding for the CBF/DREB subfamily and 65 genes coding for the ERF subfamily in A.thaliana.…”

“…We have focused on potato ERF genes because of the economic importance of this plant species worldwide (Bouaziz et al 2012(Bouaziz et al , 2013(Bouaziz et al , 2015Charfeddine et al 2015a, b).…”

Overexpression of StDREB2 Transcription Factor Enhances Drought Stress Tolerance in Cotton (Gossypium barbadense L.)

“…The functional proteins belong to the first group and include the detoxification enzymes, membrane proteins, osmolytes biosynthesis enzymes, and proteins mediating macromolecules protection, while the second group includes the regulatory proteins such as proteinases, protein kinases, and transcription factors that regulate genes expression and signal transductions [ 8 , 29 ]. Many transcription factors have been identified and showed potential in enhancing plant tolerance to different harmful stresses through regulating the expression of the downstream stress-related genes [ 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Dehydration-responsive element binding (DREB) transcription factors belong to the AP2/ERF family and comprise DREB1 and DREB2 , which play a main role in regulating stress-tolerance pathways in plants [ 30 , 31 ].…”