Bacterial but not fungal challenge up‐regulates the transcription of Coleoptericin genes in Tenebrio molitor

Antimicrobial peptides (AMPs) are effector candidates that elicit humoral immunity in invertebrates. AMPs facilitate bacterial clearance by either physically disrupting the microbial membranes or the intracellular targets. In the Coleopteran pest, Tenebrio molitor, transcriptional regulation of AMPs has been studied in the context of innate immune signaling cascades and antimicrobial immunity. Here, we report the transcriptional response of three AMP genes, Coleoptericin A, B, and C (TmCole A, B and C) in T. molitor in response to bacterial (Escherichia coli, Staphylococcus aureus), and fungal (Candida albicans) challenges. These genes were expressed essentially in the gut and hemocytes followed by the integument tissue of the T. molitor larva. Further, these genes were highly expressed in the late‐larval, pupal, and early adult stages. Furthermore, while all of these transcripts were highly upregulated in the fat body and Malpighian tubules after bacterial challenge, TmCole B and TmCole C were induced in the gut after E. coli challenge. Fungal stimulation was not required for the upregulation of the transcription of Coleoptericin genes in T. molitor.