Abstract
Safflower (Carthamus tinctorius L.) is a plant in the family of Asteraceae, and the dried tubular flowers are used as medicine, which contain active ingredients such as safflower yellow pigment and safflower glycosides. They play important roles in many fields. NF-Y, as an important transcription factor in plants, regulates a variety of plant life activities. In this study, we identified and analysed 11 CtNF-Y gene family members from safflower for the first time. Their core motifs, which are conserved structural domains, gene structures, and cis-acting elements, are described in this study. In addition, there was good collinearity between safflower CtNF-Y and other species. Protein-protein interaction network analysis showed that the CtNF-YA1 and CtNF-YB subfamilies were the core proteins of the interaction network. Real-time quantitative PCR (qRT-PCR) studies showed that the expression level of the CtNF-Y gene was regulated by safflower flower colour and safflower flowering period. Subcellular localisation results showed that three CtNF-Y proteins were located in the nucleus, the cellular regulatory centre of the plant. This study will provide valuable insights into the selection of key candidate genes in the network of regulatory mechanisms for the formation of safflower flower colour and flowering time.