Silencing in Apolygus lucorum of the olfactory coreceptor Orco gene by RNA interference induces EAG response declining to two putative semiochemicals.
Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is an agronomically important pest that causes severe economic damage to the cotton, fruit, and vegetable industries. Similar to other insects, A. lucorum can perceive and discriminate olfactory cues. A highly conserved and broadly expressed olfactory coreceptor (Orco) is crucial for insect olfaction, and Orco orthologs have been identified in several insect species. In this study, a homology-based polymerase chain reaction (PCR) method was utilized to identify AlucOrco, an Orco ortholog essential for olfaction in A. lucorum. AlucOrco shares significant sequence homology with known Orco proteins in other insects. Quantitative real-time PCR (qRT-PCR) analysis revealed that AlucOrco was abundantly expressed in adult A. lucorum. AlucOrco expression level was the highest in the antennae; by contrast, AlucOrco showed negligible expression level in other tissues. We injected AlucOrco siRNA into the conjunctivum between the prothorax and mesothorax of A. lucorum and evaluated its expression 36 h after RNA interference. The results of qRT-PCR demonstrated that the level of mRNA expression was significantly reduced (>90%) in AlucOrco siRNA-treated A. lucorum than in water-injected and non-injected controls. The electroantennogram responses of A. lucorum to two putative semiochemicals, trans-2-hexenal and trans-2-hexenyl butyrate, were also reduced significantly (∼80%) in RNAi-treated A. lucorum than in the controls. These results suggest that AlucOrco is crucial in mediating odorant perception of A. lucorum, especially in perceiving trans-2-hexenal and trans-2-hexenyl butyrate.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Yan-Le
YL
Zhou
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Xiao-Qiang
XQ
Zhu
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Shao-Hua
SH
Gu
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Huan-huan
HH
Cui
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Yu-Yuan
YY
Guo
Department of Biological Chemistry, Rothamsted Research, Harpenden AL5 2JQ, UK.
Jing-Jiang
JJ
Zhou
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address: yjzhang@ippcaas.cn.
Yong-Jun
YJ
Zhang
D000595:Amino Acid Sequence; D000818:Animals; D057506:Arthropod Antennae / Q000502:physiology*; D001483:Base Sequence; D055724:Electrophysiological Phenomena; D005260:Female; D006430:Hemiptera / Q000235:genetics*; D019476:Insect Proteins / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009758:Nymph / Q000378:metabolism; D010063:Ovum / Q000378:metabolism; D010675:Pheromones / Q000235:genetics*; D010802:Phylogeny; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D018035:Receptors, Odorant / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D019476:Insect Proteins; D010675:Pheromones; D018035:Receptors, Odorant
Apolygus lucorum; Electroantennogram; Expression profile; Olfactory coreceptor; RNA interference