RNA silencing of hormonal biosynthetic genes impairs larval growth and development in cotton bollworm, Helicoverpa armigera.

RNA silencing of hormonal biosynthetic genes impairs larval growth and development in cotton bollworm, Helicoverpa armigera. J Biosci. 2020;45: Authors: Jaiwal A, Natarajaswamy K, Venkat Rajam M Abstract The cotton bollworm, Helicoverpa armigera, is a highly polyphagous pest, causing enormous losses to various economically important crops. The identification and in vitro functional validation of target genes of a pest is a prerequisite to combat pest via host-mediated RNA interference (RNAi). In the present study, six hormonal biosynthesis genes of H. armigera were chosen and evaluated by feeding insect larvae with dsRNAs corresponding to each target gene, viz., juvenile hormone acid methyltransferase (HaJHAMT), prothoracicotropic hormone (HaPTTH), pheromone biosynthesis-activating peptide (HaPBAP), molt regulating transcription factor (HaHR3), activated protein 4 (HaAP-4) and eclosion hormone precursor (HaEHP). The loss of function phenotypes for these hormonal genes were observed by releasing second instar larvae on to artificial diet containing target gene-specific dsRNAs. Ingestion of dsRNAs resulted in mortality ranging from 60% to 90%, reduced larval weight, phenotypic deformities and delayed pupation. The quantitative real-time PCR (qRT-PCR) analysis showed that the target gene transcript levels were decreased drastically (31% to 77%) as compared to control or unrelated control (GFP-dsRNA), and correlated well with the mortali...
Source: Journal of Biosciences - Category: Biomedical Science Authors: Tags: J Biosci Source Type: research