Spatio-temporal Expression Analysis of HaDH and HaDHR in Helicoverpa armigera
Zhou Zhou *
College of Agriculture, Xinyang Agriculture and Forestry University, Xinyang Key Laboratory of Agricultural Microbial Resources Development and Utilization, Xinyang, Henan, 464000, China and Xinyang Plant Protection Microorganism Engineering Technology Center, Henan Province, Xinyang, Henan, 464000, China.
Yongli Li
College of Agriculture, Xinyang Agriculture and Forestry University, Xinyang Key Laboratory of Agricultural Microbial Resources Development and Utilization, Xinyang, Henan, 464000, China and Xinyang Plant Protection Microorganism Engineering Technology Center, Henan Province, Xinyang, Henan, 464000, China.
Pengliang Pan
College of Agriculture, Xinyang Agriculture and Forestry University, Xinyang Key Laboratory of Agricultural Microbial Resources Development and Utilization, Xinyang, Henan, 464000, China and Xinyang Plant Protection Microorganism Engineering Technology Center, Henan Province, Xinyang, Henan, 464000, China.
*Author to whom correspondence should be addressed.
Abstract
The cotton bollworm (Helicoverpa armigera) is a major agricultural pest in the world, belonging to the family Noctuidae within the order Lepidoptera, and undergoes diapause in the pupal stage. During the pupal stage, HaDH acts on the prothoracic gland to stimulate the synthesis of ecdysteroids, playing a crucial role in diapause termination. The functional activation of DH requires binding to its receptor, the diapause hormone receptor (DHR), and the tissue-specific expression of DHR varies across insect species. The regulatory mechanism of HaDH during H. armigera development remains to be elucidated. This study focuses on the spatio-temporal expression analysis of diapause hormone (HaDH) and diapause hormone receptor (HaDHR) in H. armigera, covering their expression patterns in the egg, larval, pupal and adult stages.The expression trends of HaDH and HaDHR were generally consistent. HaDH was expressed throughout the entire life cycle of H. armigera, with expression mainly localized to the head; its expression levels followed the pattern: lowest in eggs, low in larvae, highest in pupae, and high in adults. HaDHR was also expressed throughout the life cycle (from egg to adult); its overall expression trend was consistent with that of HaDH: lowest in eggs, low in larvae, high in pupae, and highest in adults. The continuous expression of both molecules throughout the H. armigera life cycle indicates that HaDH is likely involved in regulating basic metabolic processes essential for insect development. The spatio-temporal expression characteristics and potential regulatory functions of HaDH and HaDHR revealed in this study provide an important basis for further elucidating the physiological roles for HaDHR in growth and development. Collectively, these studies illustrate that HaDHR not only universally participates in insect diapause regulation but also extends its functional roles to multiple developmental stages, including embryonic development, larval growth, development of pupae and moth.
Keywords: Helicoverpa armigera, quantitative real-time PCR, diapause hormone, diapause hormone receptor, developmental stages