Objective   TIFY protein is a key regulator of the JA signalling pathway and plays a significant regulatory role in plant growth and development, abiotic stress and the accumulation of secondary metabolites. The identification of the TIFY gene in Isodon rubescens provides a theoretical foundation for the breeding of I. rubescens with enhanced stress tolerance and the investigation of the synthesis of secondary metabolites.

  Method  TIFY family was identified using bioinformatic methods based on the full-length transcriptome database of I. rubescens. Expressions of the genes in tissues were analyzed by RT-qPCR.

  Result   (1) A total of 12 IrTIFYs genes were identified in I. rubescens. (2) The amino acid length was 124—378, the molecular weight 13 924.89—39 692.38 Da, and the isoelectric point ranged from 5.05 to 9.69. All members were unstable proteins, except for IrTIFY10. IrTIFY proteins were all located in the nucleus and were hydrophilic proteins without signal peptides. (3) Structural analysis indicates that IrTIFY proteins lack transmembrane structure and that the most abundant secondary structure type is random coil. Furthermore, all TIFY proteins contain multiple phosphorylation sites. (4) The IrTIFY gene family had weak codon preference, with a slight tendency to use codons ending in A or U. (5) There were many light-, hormone-, and stress-responsive cis-elements in the IrTIFY gene family, but cis-elements were difference in numbers and types among different members.（6）Evolutionary tree analysis showed that the 12 members of the TIFY family were divided into four subfamilies: PPD (IrTIFY2), ZML (IrTIFY3/8/10), TIFY (IrTIFY7/12), and JAZ (IrTIFY1/4/5/6/9/11). They were closest to that of Salvia miltiorrhiza of Labiaceae family. (7) RT-qPCR analysis revealed that the expression of all 12 members of the TIFY family of I. rubescens in different tissues was as follows: leaves > stems > roots, and most of them were significantly different.

  Conclusion  Based on the above results, it is hypothesised that the TIFY gene family plays an important regulatory role in the growth and development of I. rubescens and may be involved in the regulation of the synthesis of secondary metabolites of I. rubescens, which lays the foundation for further in-depth study of the function of the TIFY gene family in I. rubescens and provides an idea for the further study of the function of the TIFY gene family in I. rubescens.