Peng He1, Patamarerk Engsontia2, Guang-Lei Chen1, Qian Yin3, Jun Wang1, Xu Lu4, Ya-Nan Zhang5, Zhao-Qun Li6, Ming He1. 1. State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, People's Republic of China. 2. Molecular Ecology and Evolution Research Unit, Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand. 3. Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, Jiangsu Province, People's Republic of China. 4. Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, People's Republic of China. 5. College of Life Sciences, Huaibei Normal University, Huaibei, People's Republic of China. 6. Key Laboratory of Tea Biology and Resource Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Science, Hangzhou, People's Republic of China.
Abstract
BACKGROUND: The white-backed planthopper (WBPH) Sogatella furcifera, the brown planthopper (BPH) Nilaparvata lugens, and the small brown planthopper (SBPH) Laodelphax striatellus (Hemiptera: Delphacidae) are rice pests that damage rice plants by sap-sucking and by transmitting viruses. Host-seeking behavior involves chemosensory receptor genes that include odorant receptors (ORs), ionotropic receptors (IRs) and gustatory receptors (GRs). RESULTS: We used genome and transcriptome data to identify 141 ORs, 28 GRs and 25 IRs in BPH; 135 ORs, 18 GRs and 16 IRs in WBPH; and 37 ORs, 14 GRs and 6 IRs in SBPH. A phylogenetic analysis identified several specific OR clades of rice planthoppers, the results indicating that these OR members might be used to respond to specific host volatiles. OR co-receptor (Orco) is the most conserved and essential OR gene among these species and RNA interference (RNAi) can decrease their mRNA expression level to <50%. RNAi knockdown rice planthoppers were anosmia and were unable to seek or locate rice plants in behavioral tests. CONCLUSION: The results demonstrate the importance of the planthopper Orco genes in locating rice plants. This information may aid in the development of RNAi-based transgenic rice and other pest management technologies.
BACKGROUND: The white-backed planthopper (WBPH) Sogatella furcifera, the brown planthopper (BPH) Nilaparvata lugens, and the small brown planthopper (SBPH) Laodelphax striatellus (Hemiptera: Delphacidae) are rice pests that damage rice plants by sap-sucking and by transmitting viruses. Host-seeking behavior involves chemosensory receptor genes that include odorant receptors (ORs), ionotropic receptors (IRs) and gustatory receptors (GRs). RESULTS: We used genome and transcriptome data to identify 141 ORs, 28 GRs and 25 IRs in BPH; 135 ORs, 18 GRs and 16 IRs in WBPH; and 37 ORs, 14 GRs and 6 IRs in SBPH. A phylogenetic analysis identified several specific OR clades of rice planthoppers, the results indicating that these OR members might be used to respond to specific host volatiles. OR co-receptor (Orco) is the most conserved and essential OR gene among these species and RNA interference (RNAi) can decrease their mRNA expression level to <50%. RNAi knockdown rice planthoppers were anosmia and were unable to seek or locate rice plants in behavioral tests. CONCLUSION: The results demonstrate the importance of the planthopper Orco genes in locating rice plants. This information may aid in the development of RNAi-based transgenic rice and other pest management technologies.