<b>Comparative transcriptome analysis of </b><b><i>Rhy</i></b><b><i>n</i></b><b><i>chophorus ferrugineus</i></b><b><i> </i></b><b>(Coleoptera: Curculionidae)</b><b><i> </i></b><b>reveals potential mechanisms involved in the toxication and detoxification of the external immune compound p-b</b><b>enzoquinone</b><b> present in oral secretions</b>

p-Benzoquinone (PBQ), a highly toxic compound, is the main active component in larval oral secretions of red palm weevil (RPW), <i>Rhy</i><i>n</i><i>chophorus ferrugineus</i>, playing critical roles in external immunity and pathogen defense. In this study, we demonstrated that pathogens effectively induce RPW larval external immune responses. On this basis, the toxicity of PBQ to third-instar larvae was determined, with poisoning symptoms observed. The differences in gene expression between larvae before and after treatment with PBQ were analyzed by transcriptome sequencing to reveal the mechanisms of PBQ toxicity on larvae and the mechanisms of detoxification in the infected larvae. The results indicated that PBQ regulates the chitinase (<i>CHI</i>) and phenoloxidase (<i>PO</i>) genes in RPW larvae, which not only affects the digestion and degradation of the old cuticle but also activates phenoloxidase, further oxidizing tyrosine for its conversion into DOPA and dopamine, resulting in the generation of melanin and different degrees of cuticular melanization. RPW larvae may detoxify the external immune-active compound PBQ through metabolic processes by regulating the expression levels of detoxifying enzyme-encoding genes, such as cytochrome P450 (<i>CYP450</i>), glutathione S-transferase (<i>GST</i>), and ATP-binding cassette transporter (<i>ABC</i>). Our research provides potential novel strategies for pest control by targeting insect metabolic detoxification systems.对苯醌（p-Benzoquinone, PBQ）是一种剧毒化合物，亦是红棕象甲（red palm weevil, RPW，学名*Rhynchophorus ferrugineus*）幼虫口分泌物的主要活性成分，在其体外免疫与病原防御过程中发挥关键作用。本研究证实，病原可有效诱导红棕象甲幼虫产生体外免疫应答。在此基础上，本研究测定了PBQ对红棕象甲三龄幼虫的毒性，并观察到中毒症状。通过转录组测序分析PBQ处理前后幼虫的基因表达差异，以揭示PBQ对幼虫的毒性机制以及受感染幼虫的解毒机制。研究结果显示，PBQ可调控红棕象甲幼虫体内的几丁质酶（chitinase, CHI）与酚氧化酶（phenoloxidase, PO）基因：一方面影响旧表皮的消化与降解，另一方面激活酚氧化酶，进一步将酪氨酸氧化转化为多巴（DOPA）与多巴胺，最终生成黑色素并引发不同程度的表皮黑化。红棕象甲幼虫或可通过调控细胞色素P450（cytochrome P450, CYP450）、谷胱甘肽S-转移酶（glutathione S-transferase, GST）以及ATP结合盒转运蛋白（ATP-binding cassette transporter, ABC）等解毒酶编码基因的表达水平，经代谢过程实现对体外免疫活性化合物PBQ的解毒。本研究为靶向昆虫代谢解毒系统的害虫防治提供了潜在新思路。