Chuanshan Zou1,2, Guifen Liu2,3, Suning Liu2,4, Shumin Liu2, Qisheng Song4,5, Jian Wang4,6, Qili Feng4, Yunlin Su7, Sheng Li2,4. 1. School of Forestry, Northeast Forestry University, Harbin, China. 2. Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China. 3. College of Life Sciences, Shanghai University, Shanghai, China. 4. Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, China. 5. Division of Plant Sciences, University of Missouri, Columbia, MO, USA. 6. Department of Entomology, University of Maryland, College Park, MD, USA. 7. Department of Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Science, Guangzhou, China.
Abstract
BACKGROUND: 20-Hydroxyecdysone (20E), a crucial insect steroid hormone, can bind to its cognate nuclear receptor composed of ecdysone receptor (EcR) and ultraspiracle (USP) to activate expression of 20E-response genes, enabling subsequent metamorphosis. In this study, we tried to find out which steroid-like compounds can block insect metamorphosis effectively and provide useful information for biopesticide study. For this purpose, we screened 126 steroid-like compounds for possible 20E antagonists using a dual-luciferase reporter assay with Drosophila melanogaster Kc and Bombyx mori Bm12 cells. RESULTS: Among 126 steroid-like compounds, three cucurbitacins (CucB, D and E) were identified as 20E antagonists in both Kc and Bm12 cells. Notably, CucB caused significant molting defects and mortality in both B. mori and D. melanogaster larvae, and dramatically hindered larval growth of Helicoverpa armigera by its anti-feeding activity. CONCLUSION: In vivo and in vitro experiments demonstrate that CucB acts as a potential insect growth regulator by antagonizing 20E activity and thus blocking molting and metamorphosis induced by 20E signaling.
BACKGROUND:20-Hydroxyecdysone (20E), a crucial insect steroid hormone, can bind to its cognate nuclear receptor composed of ecdysone receptor (EcR) and ultraspiracle (USP) to activate expression of 20E-response genes, enabling subsequent metamorphosis. In this study, we tried to find out which steroid-like compounds can block insect metamorphosis effectively and provide useful information for biopesticide study. For this purpose, we screened 126 steroid-like compounds for possible 20E antagonists using a dual-luciferase reporter assay with Drosophila melanogaster Kc and Bombyx mori Bm12 cells. RESULTS: Among 126 steroid-like compounds, three cucurbitacins (CucB, D and E) were identified as 20E antagonists in both Kc and Bm12 cells. Notably, CucB caused significant molting defects and mortality in both B. mori and D. melanogaster larvae, and dramatically hindered larval growth of Helicoverpa armigera by its anti-feeding activity. CONCLUSION: In vivo and in vitro experiments demonstrate that CucB acts as a potential insect growth regulator by antagonizing 20E activity and thus blocking molting and metamorphosis induced by 20E signaling.