Role of the transcription factor taiman in moulting and ovarian development of nilaparvata lugens

Abstract

Juvenile hormone (JH) regulates development, reproduction, diapause and polyphenism. The Methoprenetolerant (Met)-Taiman (Tai) complex functions as a JH receptor. The brown planthopper (Nilaparvata lugens) is one of the most devastating insect pests of rice in eastern Asia. The role of brown planthopper Tai (NlTai) in moulting and ovarian development remains unknown. In this study, NlTai was cloned, and sequence analysis revealed that NlTai contains conserved bHLH, PAS-A, and PAS-B domains. NlTai was widely expressed in all stages. In adults, this gene was expressed in all the tested tissues, with prominent expression in the wing. After downregulation of NlTai by RNAi, the ratio of ecdysis failure increased significantly. Moreover, we found that the pre-oviposition period was prolonged, and the total number of eggs laid was significantly reduced, after NlTai downregulation. These results indicate that NlTai is involved in moulting and ovarian development. Downregulation of NlMet and NlTai, either alone or together, affected ovarian development, suggesting the importance of JH signalling in ovarian development. Future studies on the molecular interaction between Met and Tai can help clarify the signalling mechanism of JH and provide a theoretical basis for the future use of the JH signalling pathway to control brown planthopper.