Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 8, 2011
Publication Date: September 5, 2011
Citation: Welch, E., Hunter, W.B., Shelby, K., Mizell, R.F., Tipping, C., Katsar, C.S., Bextine, B.R. 2011. Leafhopper comparative genomics - Identifying similarities and differences across Leafhopper vectors of Xylella fastidiosa . Southwestern Entomologist. 36:305-321.
Interpretive Summary: A genomics approach was used to compare the transcripts of three leafhoppers (glassy-winged sharpshooter, blue-green sharpshooter, and black-winged sharpshooter) which are vectors of plant pathogenic bacteria, Xylella fastidiosa, a plant pathogen of fruit crops. Genetic comparisons of the 43,400 available genetic sequences demonstrated an available set of 4,800 specific sequences within each leafhopper. Approximately 40-48% of the genes were identified as common physiology. These are predicted to be approximately one-fourth of the active genes of these leafhoppers. Examination of enzymes which play a vital role in the internal metabolism and physiology of insects along with additional analyses demonstrated significant differences suitable for designing species-specific targeting of these genes within leafhoppers. Strategies like RNA-interference should be effective management tools to reduce leafhopper abundance, and/or reduce transmission of plant pathogens.
Leafhoppers, (Hemiptera) are considered the second most important group of plant pathogen vectors. Three leafhopper species which transmit Xylella fastidiosa, a plant pathogen of fruit crops, were examined by comparison of the available expressed sequence tags, ~43,400 ESTs (Hunter datasets, National Centre Biotechnology Information). The plant-pathogenic bacterium, Xylella fastidiosa is the causal agent of Pierce’s disease of grapevine. Examination of gene expression across these leafhopper species, the glassy-winged sharpshooter, Homalodisca vitripennis, blue-green sharpshooter, Graphocephala atropunctata, and black-winged sharpshooter, Oncometopia nigricans, compared approximately 4,800 specific transcripts for each species, with most of these (~40-48%) being identified as house-keeping. These are predicted to be approximately one-fourth of the active genes of these leafhoppers, based on comparative analysis of genomes of other insects in the order Hemiptera. Study of transcripts specific to delta-9 desaturase enzymes which play a vital role in the internal metabolism and physiology of insects, with additional analyses demonstrated significant differences for species-specific targeting of these genes within leafhoppers. Strategies like RNA-interference should be able to design specific and effective management tools to reduce leafhopper abundance, and/or reduce transmission of plant pathogens.