Objective To clone the CtFD1 and CtFD2 genes from the genome of Carthamus tinctorius and perform bioinformatics, expression specificity, and subcellular localization analyses. Methods The CtFD1 and CtFD2 genes were screened and cloned based on the C. tinctorius genome. Bioinformatics online tools were used to analyze physicochemical properties, conserved domains, and other features. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine tissue-specific expression patterns. Subcellular localization was observed using a tobacco transient expression system. Soluble expression of the proteins was achieved by optimizing inducer concentration and temperature. Results The coding sequences (CDS) of CtFD1 and CtFD2 were 726 bp and 540 bp in length, encoding 241 and 179 amino acids, respectively. Both proteins contained a typical bZIP transcription factor binding domain, which were hydrophilic, and localized to the nucleus. Phylogenetic analysis indicated a close evolutionary relationship with Artemisia annua. Tissue expression analysis showed that CtFD1 and CtFD2 were most highly expressed in shoot apical meristem (SAM). Prokaryotic expression analysis revealed that both proteins were abundantly expressed in the supernatant at 16  ℃ with an IPTG concentration of 0.2 mmol/L. Conclusion The CtFD1 and CtFD2 genes belong to the bZIP family and exhibit the highest expression levels in the SAM of C. tinctorius, suggesting that they may play important roles in regulating flowering. This study provides a scientific basis for further functional characterization of these genes and elucidation of the flowering mechanism in C. tinctorius.

Carthamus tinctorius L.  /  CtFDs gene  /  gene cloning  /  bioinformatics analysis  /  expression analysis