Molecular cloning and expression analysis of the transcription factor gene SabZIP from Vaccinium corymbosum L.

The bZIP (basic leucine zipper) genes are an important family of transcription factors in plants, encoding transcriptional regulators with a variety of functions involved in developmental and physiological processes. In this study, the conserved domain of the bZIP gene in Vaccinium corymbosum L. was cloned using two degenerate primers, and the 5' terminal and 3' terminal of the gene were amplified by using rapid amplification of cDNA ends (RACE) methods. The complete cDNA sequence termed as SabZIP was obtained. Sequence analysis showed that the nucleotide sequence of SabZIP was 1451 bp, containing an open reading frame (ORF) of 1077 bp and encoding a protein with 358 amino acids. The alignment analysis indicated that the predicted protein sequence contained two typical Leucine zipper structure domain and basic domain DNA-binding domain. Homology analysis showed that the SabZIP protein had 58 and 56% homology with bZIP from Corylus heterophylla and Medicago sativa, respectively. And its hydrophobicity/hydrophilic, physio-chemical properties, phylogenetic tree, and main functional domains were predicted. Real-time quantitative polymerase chain reaction (Real-Time PCR) analysis was performed for SabZIP treated with a low-temperature of 4°C. The results showed that SabZIP gene expression was increased 2 h after being cold induced and reached a peak after 8 h, and then decreased. SabZIP might play a key role during the development of cold resistant molecular mechanisms in Vaccinium corymbosum L.