Comparative Analysis of Jakovlev (Hemiptera: Miridae) Immune Responses to Fungal and Bacterial Pathogens.

The wide-spread culture of transgenic Bt cotton resisting the infamous cotton bollworms has reduced the adoption of broad-spectrum insecticides to a large extent. Consequently, the non-targeted insect Jakovlev has become a major cotton pest in China. Entomopathogenic microbes show promising results for controlling this pest in the future, but innate immune responses to these pathogens are poorly understood. Here, we used the entomopathogenic fungus and the Gram-negative pathogenic bacteria to infect nymphs, followed by high throughput RNA-seq to analyze the immune transcriptomes of in response to the two pathogens. A total of 150 immunity-related genes were identified, including pattern recognition receptors, extracellular signal modulators, signal pathways (Toll, IMD, JNK, and JAK/STAT), and response effectors. Further quantitative real-time PCR analysis demonstrated that and were recognized by different receptors (GNBP and PGRP, respectively); activated Toll pathway and IMD pathway respectively; and both induced expression of the effector gene Defensin. However, melanization is suppressed in -infected nymphs. Collectively, this study provides a transcriptomic snapshot of the immune system, and at the genetic level, gains multifaceted insights of the immune response to fungal and Gram-negative bacterial pathogens. Ultimately this work pioneers the study of molecular mechanisms underlying immune interactions between and its pathogens and assists in the development of novel mitigation strategies to control this pest.