College of Forestry, Northwest A&F University, Xianyang 712100, China.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
Int J Mol Sci. 2022 Sep 30;23(19):11578. doi: 10.3390/ijms231911578.
Bark beetles mainly rely on detoxification enzymes to resist the host tree's defense against oleoresin terpenes. Cytochrome P450 enzymes (CYPs) play an important role in the detoxification of plant allelochemicals and pesticides in insect. One P450 gene () is associated with the response of (+)-α-pinene in . However, the regulatory mechanism of this P450 gene response to (+)-α-pinene is still unknown. In this study, spatiotemporal expression profiling indicated that was highly expressed in adult and larval stages of , and it was predominantly expressed in fat body, midgut, and Malpighian tubules of adults. Moreover, the expression of significantly increased after exposure to (+)-α-pinene, and depletion of it decreased the tolerance of adults to (+)-α-pinene. In addition, (+)-α-pinene treatment induced the expression of the transcription factors cap 'n' collar isoform C () and its binding factor muscle aponeurosis fibromatosis (), elevated the level of hydrogen peroxide (HO), and increased the activities of antioxidant enzymes. Silencing suppressed expression and enhanced the susceptibility of beetles to (+)-α-pinene. Similarly, application of the reactive oxygen species (ROS) scavenger N-acetylcysteine reduced the production and accumulation of HO, suppressed the expression of , and and led to decreased tolerance of adults to (+)-α-pinene. In contrast, ingestion of the CncC agonist curcumin elevated expression and enhanced (+)-α-pinene tolerance. The results demonstrate that, in , (+)-α-pinene induces via activation of the ROS/CncC signaling pathway.
松墨天牛主要依赖解毒酶来抵抗宿主树对松脂萜烯的防御。细胞色素 P450 酶（CYPs）在昆虫对植物化感物质和杀虫剂的解毒中起着重要作用。一个 P450 基因（）与对 (+)-α-蒎烯的反应有关。然而，这个 P450 基因对 (+)-α-蒎烯反应的调节机制尚不清楚。在这项研究中，时空表达谱分析表明，在墨天牛的成虫和幼虫阶段高度表达，并且在成虫的脂肪体、中肠和马氏管中主要表达。此外，暴露于 (+)-α-蒎烯后，的表达显著增加，而其耗竭则降低了成虫对 (+)-α-蒎烯的耐受性。此外，(+)-α-蒎烯处理诱导转录因子 cap 'n' collar 同工型 C ()及其结合因子肌肉腱膜纤维瘤 ()的表达，提高了过氧化氢 (HO)的水平，并增加了抗氧化酶的活性。沉默 抑制了 表达，增强了甲虫对 (+)-α-蒎烯的敏感性。同样，活性氧 (ROS)清除剂 N-乙酰半胱氨酸的应用减少了 HO 的产生和积累，抑制了 、和 的表达，导致成虫对 (+)-α-蒎烯的耐受性降低。相比之下，CncC 激动剂姜黄素的摄入提高了 表达，增强了 (+)-α-蒎烯的耐受性。研究结果表明，在墨天牛中，(+)-α-蒎烯通过激活 ROS/CncC 信号通路诱导 表达。
