A Comparative Transcriptomic Analysis of X-Ray Irradiation Responses Identifies Candidate Biomarker Genes in Bactrocera dorsalis Larvae

Bactrocera dorsalis (Diptera: Tephritidae) ranks among the most serious quarantine pests threatening global fruit and crop production. Irradiation has been adopted worldwide as an eco-friendly phytosanitary treatment strategy, yet how B. dorsalis responds to irradiation is not fully understood. To investigate the transcriptional response to irradiation, third-instar B. dorsalis larvae were exposed to two X-ray doses: a sub-effective dose of 15 Gy and a phytosanitary dose of 120 Gy. Comparative transcriptomic profiling revealed a clear dose-dependent escalation in the number of differentially expressed gene (DEGs). While 15 Gy primarily disrupted basic metabolism and cuticle integrity, 120 Gy induced a systemic metabolic collapse coupled with severe genotoxic stress, activating DNA repair, lysosomal degradation, and the JAK-STAT signaling pathway. Notably, we identified nine dose-specific candidate biomarker genes that are exclusively regulated at the phytosanitary dose. These findings elucidate the molecular network mediating radiation-induced mortality and provide rapid molecular diagnostic tools for validating phytosanitary irradiation efficacy and optimizing pest management strategies.