Expression of 1474 genes co-expressed with DcMYC2b in the turquoise module.

<i>Dendrobium catenatum</i> is an orchid herb used in traditional Chinese medicine with high pharmacological and nutritional value. <i>D. catenatum</i> obtained by simulated wild cultivation is highly favored due to its high quality. However, southern blight disease caused by<i> </i><i>Sclerotium delphinii</i> leads to devastating losses in simulated wild cultivation of <i>D. catenatum</i>. Previously, we showed that the core jasmonic acid (JA) signaling factor DcMYC2b positively regulates plant defense against southern blight disease. We found that the MYC2 mode of action in plant defense is species-specific, but the underlying regulatory mechanism of DcMYC2b is unclear. Here, a comprehensive analysis involving weighted gene coexpression network analysis (WGCNA), metabolomics, and transcription factor -centered yeast one-hybrid (TF-centered Y1H) assays was performed to elucidate the crosstalk between the core JA signaling and phenylpropanoid pathways, as well as the molecular mechanisms underlying the defense of <i>D. catenatum</i> against southern blight disease.