Genome-Wide Identification and Functional Characterization of the TIFY Gene Family Associated with Abiotic Stress and Hormone Response in Carthamus tinctorius L.

Jasmonate-ZIM domain (JAZ) proteins act as core negative regulators of jasmonic acid signaling and mediate plant stress adaptation, developmental progression, and secondary metabolism. Safflower (Carthamus tinctorius L.) is an economically important Asteraceae crop with medicinal, edible oil, and ornamental values; however, the evolutionary characteristics and molecular functions of its TIFY gene family remain poorly characterized. In the present study, we performed a genome-wide identification of the safflower CtTIFY family, followed by systematic analyses of phylogenetic relationships, chromosomal distribution, gene synteny, structural features, conserved motifs, and promoter cis-regulatory elements. Transcriptome profiling, quantitative real-time PCR (qRT-PCR) validation under multiple abiotic stresses and methyl jasmonate treatment, and subcellular localization assays were further conducted to explore divergence in transcript expression levels among family members. A total of 14 CtTIFY genes were identified and categorized into three subfamilies: JAZ, TIFY, and ZML. Segmental duplication was the primary driving force for CtTIFY family expansion, and distinct structural and physicochemical divergences were detected among different subfamilies. CtTIFY genes harbor abundant cis-elements responsive to stresses, hormones, and light signals, and exhibit transcriptional correlations with safflower floral development, seed germination, and seed-oil accumulation. Among them, CtJAZ1, CtJAZ6, and CtJAZ7 represent key candidate genes showing transcriptional responses to JA signals and multiple abiotic stresses. Subcellular localization showed that CtTIFY proteins are predominantly nuclear-localized with potential nucleocytoplasmic shuttling. This study systematically characterizes the evolutionary dynamics and divergence in expression levels of the safflower CtTIFY family, identifies candidate genes associated with stress response and quality-related processes, and provides fundamental genetic resources for future safflower molecular-breeding research.