Silencing the HaAK Gene by Transgenic Plant-Mediated RNAi Impairs Larval Growth of Helicoverpa armigera. International journal of biological sciences

licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited. Received: 2014.09.02; Accepted: 2014.11.05; Published: 2015.01.01 Insect pests have caused noticeable economic losses in agriculture, and the heavy use of insecticide to control pests not only brings the threats of insecticide resistance but also causes the great pollution to foods and the environment. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been is currently developed for protection against insect pests. In this study, we used this technology to silence the arginine kinase (AK) gene of Helicoverpa armigera (HaAK), encoding a phosphotransferase that plays a critical role in cellular energy metabolism in invertebrate. Transgenic Arabidopsis plants producing HaAK dsRNA were generated by Agrobacterium-mediated transformation. The maximal mortality rate of 55 % was reached when H. armigera first-instar larvae were fed with transgenic plant leaves for 3 days, which was dramatically higher than the 18 % mortality recorded in the control group. Moreover, the ingestion of transgenic plants significantly retarded larval growth, and the transcript levels of HaAK were also knocked down by up to 52%. The feeding bioassays further indicated that the inhibitio