AaJAZ8 forms an extensive interaction network with AaJAZ proteins and two novel AaMYC transcription factors in Artemisia annua.

Artemisia annua is the source plant for artemisinin production. Variable cultivation conditions are important factors affecting plant growth and artemisinin yield. The jasmonic acid signaling pathway is a crucial mechanism by which plants cope with stress, with the jasmonate ZIM-domain (JAZ) genes playing key roles in this pathway. While the JAZ gene family in A. annua has not yet been comprehensively characterized, this study conducted an in-depth analysis of JAZ genes, including identification and molecular characteristics such as genetic variation and alternative splicing, as well as short-term expression responses to methyl jasmonate (MeJA) in the LQ-9 genotype. The results showed that 18 AaJAZ genes were identified in the h0 haplotype, whereas 17 were identified in the h1 haplotype. A total of 967 single nucleotide polymorphisms (SNPs) and 267 insertion/deletion (indels) were identified across 17 pairs of alleles, and four AaJAZ genes showed alternative splicing events. Ten other AaJAZ genes exhibited specific and significant induction by MeJA exclusively in old leaves. Through gene expression profiling and protein-protein interaction validation, AaJAZ8 was found to form homodimers and interact with 10 AaJAZs. Additionally, yeast two-hybrid assays suggested potential physical interactions between AaJAZ8 and both AaMYC24 and AaMYC26. This study systematically characterizes the JAZ protein family in A. annua, identified novel AaJAZ8-interacting proteins, and provides a foundation for further understanding the role of AaJAZ8 in the jasmonate signaling network.