Proteome analysis of Bemisia tabaci suggests specific targets for RNAi mediated control

RNA interference offers effective control of several economically important insect pests. Bemisia tabaci is an important field crop pest, which causes significant yield loss worldwide. In our earlier study, we have demonstrated successful control of B. tabaci through transgenic plant mediated RNAi. However, selection of target genes without off-target effect(s) has been major concern so far and therefore, a critical exploration for B. tabaci specific targets is frantically required. In this study, we have followed proteomics approach to discover B. tabaci specific targets for RNAi and identified unique nucleotide sequences in functional genes (n=11) of the pest. For this, we have developed proteome profile of B. tabaci extract using two-dimensional electrophoresis. A total of 504 protein spots were analyzed on mass-spectrometer and 453 proteins including 246 non-redundant proteins have been identified successfully. Complementation of the proteome data with available nucleotide database has helped us to interpret the unique nucleotide sequences. These nucleotide stretches may serve as environmentally safe targets for RNAi mediated control of the pest through crop genetic engineering. To the best of our knowledge, it is the most complete proteome of any whitefly species. We have also demonstrated application of proteomics in the identification of functional transcripts for RNAi.

Insects cause major loss to crop productivity through direct and indirect damages. Among them, hemipteran group of insects are major contributor of global crop yield loss. In current study, gel based proteome profile of B. tabaci (one of the major hemipteran crop insect pest) is developed and characterized, which is a gap area in field of whitefly biology. It is an important data set of future whitefly studies like insect-plant interaction, virulence of whiteflies, their control program and discovery of new pesticides. Out of various control strategies, RNA interference offers a great potential to combat the whitefly successfully. However, the uniqueness of target genes and off target impact of the technology remains a challenge to scientific community. We used our proteome data set for the identification of B. tabaci specific gene targets for RNAi mediated control. The identified genes are critical for the life cycle of B. tabaci hence, could be proven as good molecules for making transgenic crop plant for efficient control of whiteflies in the field.