| Abstract:Objective: To study the spatial expression difference of GubZIP genes and its expression pattern under exogenous ABA treatment, clone and analyze the promoter sequences of key enzyme genes CHI, CHS and β-As of G. uralensis, providing a basis for further analysis of the molecular mechanism of ABA-responsive bZIP transcription factor regulating the biosynthesis of active components in G. uralensis. Methods: Real-time quantitative PCR (RT-qPCR) was used to analyze the expression pattern of GubZIPs under exogenous ABA treatment using the hairy root culture system of G. uralensis and then the spatial expression difference of GubZIPs in three-year-old licorice was studied. The promoter sequences were obtained from the genome of G. uralensis by TBtools software, and the potential key regulatory elements on the promoters were analyzed by bioinformatics. Results: The expression patterns of the Glycyrrhiza uralensis genes GubZIP1, GubZIP5, GubZIP33 and GubZIP56, which encode transcription factors involved in plant hormone ABA response, vary under different ABA treatment conditions, with the response of GubZIP1 and GubZIP33 being the most significant. The expression of GubZIPs in different tissues of licorice showed that GubZIP1 and GubZIP5 were highly expressed in the root, and GubZIP33 and GubZIP56 were highly expressed in the leaves. Based on the licorice genome, the promoter sequences of key enzyme genes CHI, CHS, and β-As in the licorice biosynthesis pathway were cloned, and the analysis results showed that the promoter region of the CHI gene has two G-box and one A-box cis-acting elements, the promoter region of the CHS gene has two ABRE and one G-box cis-acting elements, and the promoter region of the β-As gene has one ABRE and one G-box cis-acting elements. Conclusion: The GubZIP1, GubZIP5, GubZIP33 and GubZIP56 in hairy roots of licorice show significant responses to ABA. Treatment with 50mg·L-1 of ABA for 3 hours is a suitable scheme for studying the ABA-related pathway in licorice. In addition, cis-acting elements that can bind to bZIP transcription factors and respond to ABA and other hormones exist in the promoter regions of key enzyme genes in licorice, laying the foundation for a deeper understanding of the molecular mechanisms of bZIP transcription factor regulation of the biosynthesis of active components in licorice in response to ABA. |
