Evolutionary Analysis of JAZ Proteins in Plants: An Approach in Search of the Ancestral Sequence

Abstract

Jasmonates are phytohormones that regulate development, metabolism and immunity. Signal transduction is critical to activate jasmonate responses, but the evolution of some key regulators such as jasmonate-ZIM domain (JAZ) repressors is not clear. Here, we identified 1065 JAZ sequence proteins in 66 lower and higher plants and analyzed their evolution by bioinformatics methods. We found that the TIFY and Jas domains are highly conserved along the evolutionary scale. Furthermore, the canonical degron sequence LPIAR(R/K) of the Jas domain is conserved in lower and higher plants. It is noteworthy that degron sequences showed a large number of alternatives from gymnosperms to dicots. In addition, ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motifs are displayed in all plant lineages from liverworts to angiosperms. However, the cryptic MYC2-interacting domain (CMID) domain appeared in angiosperms for the first time. The phylogenetic analysis performed using the Maximum Likelihood method indicated that JAZ ortholog proteins are grouped according to their similarity and plant lineage. Moreover, ancestral JAZ sequences were constructed by PhyloBot software and showed specific changes in the TIFY and Jas domains during evolution from liverworts to dicots. Finally, we propose a model for the evolution of the ancestral sequences of the main eight JAZ protein subgroups. These findings contribute to the understanding of the JAZ family origin and expansion in land plants.