Knockout of silk fibroin genes in Plutella xylostella results in decreased fitness and performance

BACKGROUND: The ability of insects to spin silk is crucial for their survival, reproduction, and interactions with the environment. The diamondback moth (DBM), Plutella xylostella, a serious agricultural pest, relies on silk production, which influences its behavior and population dynamics. RESULTS: This study employed CRISPR/Cas9 technology to knock out three genes, that is, silk fibroin heavy chain (PxFibH), silk fibroin light chain (PxFibL), and fibrohexamerin (PxP25), to investigate their roles in silk gland development and related biological traits. We successfully generated PxFibH, PxFibL, and PxP25 knockout mutants, which displayed defective cocoon formation and developed into naked pupae. Further analysis revealed significant alterations in silk gland structure and various biological parameters, including increased larval mortality, prolonged developmental time, reduced pupal weight, and shortened adult lifespan. CONCLUSIONS: These findings highlight the importance of silk fibroin genes in silk production and growth development in P. xylostella, positioning them as potential targets for innovative pest control strategies. © 2025 Society of Chemical Industry.