Identification of an intraspecific alarm pheromone and two conserved odorant-binding proteins associated with (E)-β-farnesene perception in aphid Rhopalosiphum padi
Identification of an intraspecific alarm pheromone and two conserved odorant-binding proteins associated with (E)-β-farnesene perception in aphid Rhopalosiphum padi
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识别与蚜虫 Rhopalosiphum padi 中 (E)-β-法尼烯感知相关的种内警报信息素和两种保守的气味结合蛋白
DOI：
10.1016/j.jinsphys.2017.07.014
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发表时间：
2017-08-01
影响因子：
2.2
通讯作者：
Chen, Julian
中科院分区：
文献类型：
--
作者：
Fan, Jia;Xue, Wenxin;Chen, Julian
(E)- β -法尼烯（EBF）是蚜虫报警信息素的常见活性成分。最近在蚜虫中报道的ordorant-binding protein （OBPs）的两个同源物OBP3和OBP7中的一个或两个都可能参与EBF感知。本研究的目的是调查蚜虫对其种内报警信息素的反应，以及OBP是负责这种反应的。本实验测试了灰蚜对EBF和新鲜粉碎蚜虫的嗅觉反应。然后，采用固相微萃取（SPME）技术从蚜虫中提取挥发物，并进行GC × GC TOF/MS分析。我们还克隆了2个OBPs cdna (RpadOBP3和RpadOBP7)，并在大肠杆菌中表达。重组蛋白RpadOBP3和RpadOBP7都能很好地结合EBF，其中RpadOBP7对EBF的亲和力比其他挥发物更强。基于高同源性OBPs的晶体结构，我们进行了同源性建模，分析了RpadOBPs与EBF之间的相互作用。综上所述，绿僵菌对粉碎后的蚜虫均有驱避作用。EBF被确定为唯一的挥发性，作为警报信息素。结果表明，OBP7是通过干扰小麦蚜虫对报警信息素的行为来控制小麦蚜虫的潜在分子靶点。
(E)-beta-farnesene (EBF) is the common active component of aphid alarm pheromone. Either or both of two orthologs of ordorant-binding proteins (OBPs), OBP3 and OBP7, recently reported in aphids, may be involved in EBF perception. The aim of this study was to investigate the respondence of the aphid Rhopalosiphum padi to its intraspecific alarm pheromone and which OBP is responsible for that response. We tested the olfactory response of the aphid R. padi to EBF and freshly crushed aphids. Then, we extracted the volatiles from crushed aphids using solid phase microextraction (SPME) for analysis with GC x GC TOF/MS. We also cloned two OBPs cDNAs in R. padi (RpadOBP3 and RpadOBP7) and expressed them in competent Escherichia coli cells. Both recombinant proteins, RpadOBP3 and RpadOBP7, bound EBF well, with RpadOBP7 having specifically stronger affinity for EBF than for other volatiles. Based on the crystal structure of the OBPs with high identity, we performed homology modeling and analyzed the interactions between RpadOBPs and EBF. In conclusion, R. padi was repelled by both EBF and crushed aphids. EBF was identified as the only volatile that acted as the alarm pheromone. Our results indicated that OBP7 is a potential molecular target to control wheat aphids by disturbing their behaviors to the alarm pheromone.