Krüppel-homologue 1regulates the development ofTuta absolutaand its cascade regulation pattern in the juvenile hormone signalling pathway

Abstract

Tomato leaf miner, Tuta absoluta (Meyrick), is one of the most destructive quarantine pests globally. It has been confirmed that Krüppel-homologue 1 ( kr-h1 ) plays a key role in the regulation of juvenile hormone (JH). However, it is unclear how kr-h1 regulates the synthesis of JH and its cascade regulation pattern in tomato leaf miner. Here, we obtained the six JH signalling genes ( kr-h1 , Methoprene-tolerant , Forkhead box O , Juvenile acid methyltransferase , Juvenile hormone esterase and Fatty acid synthase 2 ), and applied RNA interference to explore the role of kr-h1 and the seven genes (plus Vitellogenin ) regulation relationship in T. absoluta . Bioinformatics analysis revealed the structural characteristics of kr-h1 protein and JH receptor Met, which contained eight C2H2 zinc finger structures and three typical domains of the bHLH-PAS family, respectively. The expression levels of Met and Vg were upregulated after RNAi of kr-h1 gene, while the gene levels of JHAMT and FAS2 were downregulated. Furthermore, topical application of JH analogue to second instar larvae could induce the expression of kr-h1 and inhibit the expression of Met . Our study reveals the mechanism by which kr-h1 regulates JH pathway genes, which could be applied to control the growth of tomato leaf miners.

Expression profiling of juvenile hormone and ecdysteroid biosynthesis genes during the development and reproduction of Phytoseiulus persimilis

“…In Grapholita molesta, silencing of GmKr-h1 prolonged the pre-oviposition period and reduced fecundity (Zhang et al 2019a). Wang et al (2023) interfered with the Vg gene of the female adult at 4 h after fertilization by dsRNA mixed with nanomaterials in solution, and the interfered sterile female adult appeared to smaller size and attened abdomen, and signi cant reduction in egg production within 24 h. In this study, silencing of PpKr-h1 resulted in a signi cant reduction in total 7-day egg production by female adult mites. Combined with the high expression of PpKr-h1 in the juvenile stage of P. persimilis, we speculate that PpKr-h1 may be involved in the regulation of embryonic development and the biosynthesis of vitellogenin in the female adult after fertilization, but little was known which genes were involved in the regulation of reproductive process.…”