Functional characterization of SmCBF genes involved in abiotic stress response in eggplant (Solanum melongena)

Temperature has important effect on the growth, development and crop yield of plants. Freezing-sensitive eggplant suffers chilling in some growing farms every early spring. The C-repeat binding factors (CBFs) are crucial transcription factors involved in cold-response pathway. In our study, we obtained three CBF genes from eggplant (Solanum melongena), designated SmCBF1, SmCBF2 and SmCBF3. Bioinformatics and phylogenetic analysis showed that each SmCBF has an AP2/ERF DNA-binding domain and belongs to the A-1 group member of the CBF/DREB1 subfamily. SmCBFs could specifically bind to the DRE/CRT cis-element on the basis of subcellular localization, transcriptional activity and DRE binding activity analysis. Based on the quantitative RT-PCR, the expression of SmCBF1, SmCBF2 and SmCBF3 with similar expression pattern were all induced by cold stress, drought, high-salinity and abscisic acid (ABA) treatments. Generally, SmCBFs are involved in regulation of the response to abiotic stress, which can be applied to molecular breeding to improve cold tolerance of eggplant.