Zhao Jing, Zhou Yunlong, Li Xiang, Cai Wanlun, Hua Hongxia
Hubei Insect Resources Utilisation and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
Hubei Insect Resources Utilisation and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
J Insect Physiol. 2017 Oct;102:18-26. doi: 10.1016/j.jinsphys.2017.08.012. Epub 2017 Sep 1.
The rice brown planthopper, Nilaparvata lugens, is an important migratory pest in many rice planting areas of Asia. The typical wing dimorphism of N. lugens gives them flexibility to adapt to different environmental cues. As an important hormone in the insect's endocrine regulation, juvenile hormone (JH) has previously been shown to participate in the wing morph determination of N. lugens. In this paper, we investigated the possible wing morph determination roles of two JH metabolic enzymes, JH esterase (JHE) and JH epoxide hydrolase (JHEH). A 1957-bp full-length cDNA sequence encoding JHEH in N. lugens (NlJHEH) was first cloned from a hemipteran insect. Except for an uncertain transmembrane segment prediction, the deduced 454-amino-acid sequence of Nljheh has all of the conserved domains of JHEHs such as the HGWP, Tyr293 and Tyr368 motif corresponding to the oxyanion hole and the residues Asp222, Glu398, and His425 in the catalytic triad. qRT-PCR results showed that both Nljhe and Nljheh had different expression timeframes between a predominantly brachypterous strain (BS) and a macropterous strain (MS) of N. lugens, indicating that these two enzymes may participate in wing dimorphism regulation in brown planthopper. Silencing Nljheh expression by dsRNA injection enhanced short wing formation in the macropterous strain of N. lugens, while the brachypterizing individuals were mainly females. Compared to the dsgfp injection control, silencing Nljhe had no brachypterizing effect. Our results indicated that NlJHEH plays an important role in the wing morph determination of N. lugens.
褐飞虱（Nilaparvata lugens）是亚洲许多水稻种植区的一种重要迁飞性害虫。褐飞虱典型的翅二型性使其能够灵活适应不同的环境线索。作为昆虫内分泌调节中的一种重要激素，保幼激素（JH）此前已被证明参与褐飞虱翅型的决定。在本文中，我们研究了两种JH代谢酶，JH酯酶（JHE）和JH环氧水解酶（JHEH）在翅型决定中可能发挥的作用。首先从一种半翅目昆虫中克隆出了褐飞虱中编码JHEH的1957 bp全长cDNA序列（NlJHEH）。除了一个不确定的跨膜片段预测外，推导的Nljheh的454个氨基酸序列具有JHEHs的所有保守结构域，如对应于氧阴离子洞的HGWP、Tyr293和Tyr368基序以及催化三联体中的Asp222、Glu398和His425残基。qRT-PCR结果表明，Nljhe和Nljheh在褐飞虱的一个主要为短翅型品系（BS）和一个长翅型品系（MS）之间具有不同的表达时间框架，这表明这两种酶可能参与褐飞虱的翅二型性调节。通过注射dsRNA沉默Nljheh的表达可增强褐飞虱长翅型品系中短翅的形成，而短翅化个体主要为雌性。与注射dsgfp作为对照相比，沉默Nljhe没有短翅化作用。我们的结果表明，NlJHEH在褐飞虱的翅型决定中起重要作用。
