Ectopic Overexpression of SsCBF1, a CRT/DRE-Binding Factor from the Nightshade Plant Solanum lycopersicoides, Confers Freezing and Salt Tolerance in Transgenic Arabidopsis

Abstract

The C-repeat (CRT)/dehydration-responsive element (DRE) binding factor (CBF/DREB1) transcription factors play a key role in cold response. However, the detailed roles of many plant CBFs are far from fully understood. A CBF gene (SsCBF1) was isolated from the cold-hardy plant Solanum lycopersicoides. A subcellular localization study using GFP fusion protein indicated that SsCBF1 is localized in the nucleus. We delimited the SsCBF1 transcriptional activation domain to the C-terminal segment comprising amino acid residues 193–228 (SsCBF1193–228). The expression of SsCBF1 could be dramatically induced by cold, drought and high salinity. Transactivation assays in tobacco leaves revealed that SsCBF1 could specifically bind to the CRT cis-elements in vivo to activate the expression of downstream reporter genes. The ectopic overexpression of SsCBF1 conferred increased freezing and high-salinity tolerance and late flowering phenotype to transgenic Arabidopsis. RNA-sequencing data exhibited that a set of cold and salt stress responsive genes were up-regulated in transgenic Arabidopsis. Our results suggest that SsCBF1 behaves as a typical CBF to contribute to plant freezing tolerance. Increased resistance to high-salinity and late flowering phenotype derived from SsCBF1 OE lines lend more credence to the hypothesis that plant CBFs participate in diverse physiological and biochemical processes related to adverse conditions.

Molecular Evidence for Functional Divergence and Decay of a Transcription Factor Derived from Whole-Genome Duplication in Arabidopsis thaliana

“…S1, blue boxes) and, with the exception of T. halophila DDF2, an LWNYS motif (Supplemental Fig. S1, orange box), which has transcriptional attenuation and transcriptional activation functions (Wang et al, 2005;Zhang et al, 2013). Despite the similarity among DREB A-1 proteins, all DDF2 proteins are missing a region of about 20 amino acids at the C terminus that in all the DDF1 proteins is Ser and Gly rich (Supplemental Fig.…”

Chilling acclimation provides immunity to stress by altering regulatory networks and inducing genes with protective functions in Cassava

“…The overexpression of SsDREB1 in Arabidopsis could result in chilling-regulated gene expression and freezing tolerance [ 53 ]. Conversely, constitutive overexpression of either LeCBF1 or AtCBF3 in transgenic tomato plants does not provide a detectable freezing tolerance [ 54 ].…”

Computational Disorder Analysis in Ethylene Response Factors Uncovers Binding Motifs Critical to Their Diverse Functions

“…Although much of the functional research on the ERFs comes from Arabidopsis, there is also evidence that orthologues from other plants perform functions in similar pathways. For example, overexpression of CBF1 from tomato could also boost cold tolerance in Arabidopsis and mutation of the highly conserved tryptophan residue shown in MoRF IIIc C1 destroyed the trans-activating ability of the tomato orthologue of AtCBF1 [50], highlighting that this MoRF corresponds to a critical motif in these important regulators of plant cold tolerance. clusters of hydrophobic residues delineated by short stretches of acidic residues and prolines within the trans-activating C-terminus [49].…”