Objective  We analyzed the characteristics of JAZ gene family in Pinus tabuliformis and its functional domain of interaction with gibberellin negative regulator DELLA protein, in order to lay a foundation for the analysis of jasmonic acid (JA) -gibberellin (GA) mediated growth/defense balance strategy in conifers with JAZ-DELLA as the core module.

  Method  This study screened and identified all JAZ genes based on the whole genome data of Pinus tabuliformis, and analyzed the basic characteristics of P. tabuliformis JAZ gene family; at the same time, a phylogenetic tree of multi-species JAZ gene family was constructed to explore the characteristics of P. tabuliformis JAZ gene family in the phylogenetic process. Furthermore, the functional domain of interaction between P. tabuliformis JAZ gene family and DELLA protein was identified by yeast two-hybrid technique.

  Result  There were 53 JAZ genes in P. tabuliformis, and the JAZ gene family of P. tabuliformis not only had TIFY and Jas conserved structures, but also evolved more abundant changes in the degron sequence. The promoter regions of multiple members of the JAZ gene family in P. tabuliformis contained cis-acting elements responding to JA and GA, and had a close evolutionary distance from several JAZ proteins in model plants. Further experiments showed that the Jas domains of 5 JAZ proteins (TIFY4, TIFY11, TIFY16, TIFY25, and TIFY59) in P. tabuliformis were interacted with PtDPL (DELLA-like), and it was clarified that the Jas domain in P. tabuliformis was the functional domain of interaction between JAZ protein and DELLA protein.

  Conclusion  This study clarified the basic sequence characteristics of JAZ gene family and identified the functional motif of protein JAZ and DELLA interaction in P. tabuliformis. At the same time, it also supplemented an important basis for the further study of JAZ gene family and JA-GA signaling pathway in conifers.