Wu Zhongzhen, Zhang He, Bin Shuying, Chen Lei, Han Qunxin, Lin Jintian
Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Guangzhou, PR China.
PLoS One. 2016 Jul 21;11(7):e0159372. doi: 10.1371/journal.pone.0159372. eCollection 2016.
The Asian citrus psyllid, Diaphorina citri is the principal vector of the highly destructive citrus disease called Huanglongbing (HLB) or citrus greening, which is a major threat to citrus cultivation worldwide. More effective pest control strategies against this pest entail the identification of potential chemosensory proteins that could be used in the development of attractants or repellents. However, the molecular basis of olfaction in the Asian citrus psyllid is not completely understood. Therefore, we performed this study to analyze the antennal and abdominal transcriptome of the Asian citrus psyllid. We identified a large number of transcripts belonging to nine chemoreception-related gene families and compared their expression in male and female adult antennae and terminal abdomen. In total, 9 odorant binding proteins (OBPs), 12 chemosensory proteins (CSPs), 46 odorant receptors (ORs), 20 gustatory receptors (GRs), 35 ionotropic receptors (IRs), 4 sensory neuron membrane proteins (SNMPs) and 4 different gene families encoding odorant-degrading enzymes (ODEs): 80 cytochrome P450s (CYPs), 12 esterase (ESTs), and 5 aldehyde dehydrogenases (ADE) were annotated in the D. citri antennal and abdominal transcriptomes. Our results revealed that a large proportion of chemosensory genes exhibited no distinct differences in their expression patterns in the antennae and terminal abdominal tissues. Notably, RNA sequencing (RNA-seq) data and quantitative real time-PCR (qPCR) analyses showed that 4 DictOBPs, 4 DictCSPs, 4 DictIRs, 1 DictSNMP, and 2 DictCYPs were upregulated in the antennae relative to that in terminal abdominal tissues. Furthermore, 2 DictOBPs (DictOBP8 and DictOBP9), 2 DictCSPs (DictOBP8 and DictOBP12), 4 DictIRs (DictIR3, DictIR6, DictIR10, and DictIR35), and 1 DictCYP (DictCYP57) were expressed at higher levels in the male antennae than in the female antennae. Our study provides the first insights into the molecular basis of chemoreception in this insect pest. Further studies on the identified differentially expressed genes would facilitate the understanding of insect olfaction and their role in the interactions between olfactory system and biological processes.
亚洲柑橘木虱（Diaphorina citri）是极具破坏性的柑橘黄龙病（HLB）或柑橘绿化病的主要传播媒介，这对全球柑橘种植构成了重大威胁。针对这种害虫更有效的害虫防治策略需要鉴定出可用于开发引诱剂或驱避剂的潜在化学感应蛋白。然而，亚洲柑橘木虱嗅觉的分子基础尚未完全了解。因此，我们开展了这项研究来分析亚洲柑橘木虱的触角和腹部转录组。我们鉴定出大量属于9个化学感受相关基因家族的转录本，并比较了它们在成年雌雄虫触角和腹部末端的表达情况。在亚洲柑橘木虱的触角和腹部转录组中总共注释了9种气味结合蛋白（OBP）、12种化学感应蛋白（CSP）、46种气味受体（OR）、20种味觉受体（GR）、35种离子型受体（IR）、4种感觉神经元膜蛋白（SNMP）以及4个编码气味降解酶（ODE）的不同基因家族：80种细胞色素P450（CYP）、12种酯酶（EST）和5种醛脱氢酶（ADE）。我们的结果表明，很大一部分化学感应基因在触角和腹部末端组织中的表达模式没有明显差异。值得注意的是，RNA测序（RNA-seq）数据和定量实时PCR（qPCR）分析表明，相对于腹部末端组织，4种柑橘木虱OBP、4种柑橘木虱CSP、4种柑橘木虱IR、1种柑橘木虱SNMP和2种柑橘木虱CYP在触角中上调表达。此外，2种柑橘木虱OBP（柑橘木虱OBP8和柑橘木虱OBP9）、2种柑橘木虱CSP（柑橘木虱OBP8和柑橘木虱OBP12）、4种柑橘木虱IR（柑橘木虱IR3、柑橘木虱IR6、柑橘木虱IR10和柑橘木虱IR35）和1种柑橘木虱CYP（柑橘木虱CYP57）在雄虫触角中的表达水平高于雌虫触角。我们的研究首次揭示了这种害虫化学感受的分子基础。对鉴定出的差异表达基因的进一步研究将有助于理解昆虫嗅觉及其在嗅觉系统与生物过程相互作用中的作用。
