Study on the Effect of Wing Bud Chitin Metabolism and Its Developmental Network Genes in the Brown Planthopper, , by Knockdown of Gene.

The brown planthopper, is one of the most serious pests of rice, and there is so far no effective way to manage this pest. However, RNA interference not only can be used to study gene function, but also provide potential opportunities for novel pest management. The development of wing plays a key role in insect physiological activities and mainly involves chitin. Hence, the regulating role of trehalase (TRE) genes on wing bud formation has been studied by RNAi. In this paper, the activity levels of TRE and the contents of the two sugars trehalose and glucose were negatively correlated indicating the potential role of TRE in the molting process. In addition, and were expressed at higher levels in wing bud tissue than in other tissues, and abnormal molting and wing deformity or curling were noted 48 h after the insect was injected with any double-stranded TRE (), even though different TREs have compensatory functions. The expression levels of , and decreased significantly 48 h after the insect was injected with a mixture of three kinds of . Similarly, the TRE inhibitor validamycin can inhibit and gene expression. However, the wing deformity was the result of the , and genes being inhibited when a single was injected. These results demonstrate that silencing of gene expression can lead to wing deformities due to the down-regulation of the and genes involved in wing development and that the TRE inhibitor validamycin can co-regulate chitin metabolism and the expression of wing development-related genes in wing bud tissue. The results provide a new approach for the prevention and management of .