Application of RNAi of Bemisia tabaci (Hemiptera: Aleyrodidae) with cDNA Library Construction

Sweet potato whitefly (Bemisia tabaci) is one of the major and alien insect pests acting as viral vector in Korea. B. tabaci can be transmitted about 100 kinds of plant viruses including tomato yellow leaf curl virus (TYLCV) in tomato. In order to control for these B. tabaci, we mainly spray agricultural chemicals. However, the chemical control of B. tabaci is becoming problem because whitefly rapidly develops resistance expression to agricultural chemicals. A lot of insect pest control methods using RNA interference (RNAi)-based technology has been studied in recent years. Besides, RNAi technology can be helpful to study the target genes with applying several methods such as, injection of dsRNA into insect body, dsRNA feeding and transgenic plant. In this study we attempted cDNA library construction using gateway system for selecting target gene in order to control B. tabaci using RNAi. As a result, we confirmed the 100~400bp of insert size, which is appropriate for RNAi. Also insert sequence was compared with DNA databases and EST databases using NCBI blast search. As a result, we confirmed that most of insert is gene associated with B. tabaci. Consequentially, we completed B. tabaci cDNA library with the titer of 1.76⨉10⁶ clones. Subsequently, we will perform the LR recombination to transfer cDNA library into TRV₂ (tobacco rattle virus) vector with att site. Then, after performing transformation using Agrobacterium tumefaciens (EHA105), we will inoculate a tomato with A. tumefaciens. Otherwise, we will be confirmed an insecticidal effect or a repellent activity against B. tabaci by changing behavior in transgenic tomato plant. Also, the most effective gene among them may be used for insect pest control.