Genome-Wide Identification and Analysis of bZIP Transcription Factors in Coptis chinensis Reveals Their Regulatory Roles in Stress Responses

The basic leucine zipper (bZIP) transcription factors play crucial roles in plant growth and stress adaptation. However, a comprehensive genome-wide analysis of this family has been lacking in the medicinal plant <i>Coptis chinensis</i>. In this study, we identified 55 bZIP genes (<i>CcbZIPs</i>) from the <i>C. chinensis</i> genome and systematically classified them into 12 subfamilies through phylogenetic analysis with <i>Arabidopsis thaliana</i>. Notably, subfamilies L and O were absent, while two orphan genes were discovered, indicating lineage-specific evolution. Expression profiling revealed that numerous <i>CcbZIPs</i> respond dynamically to temperature and light stresses in a tissue-specific manner. These findings provide a foundation for understanding the regulatory roles of CcbZIPs in environmental adaptation and secondary metabolism, offering potential genetic targets for future breeding aimed at improving stress tolerance and medicinal compound production in <i>C. chinensis</i>.