Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 10/9/2009
Publication Date: 12/9/2009
Citation: Bextine, B., Hunter, W.B., Schreiber, H., Hail, D. 2009. Phylogenetic analysis of heat shock proteins in Glassy-winged sharpshooter. p. 13-18. CDFA Pierce's Disease Control Program Research Symposium, December 9-11, 2009, Sacramento, California. Available: http://www.cdfa.ca.gov/pdcp/2009 Research Proceedings.html. Interpretive Summary: Heat shock proteins are critical to sustaining life in living organisms. Four heat shock protein transcripts were produced from the economically important leafhopper pest, the glassy-winged sharpshooter (GWSS). In this study, we generated and analyzed sequences from the leafhopper cDNA libraries, which represented approximately one-fifth of the predicted protein coding genes in the GWSS. We isolated four partial sequences from a large family of proteins called heat shock proteins, HSP. Although they are called HSP, these proteins actually perform many activities in the cell that are necessary for GWSS to survive stresses like extreme temperatures, pesticides, and disease infections. This study compares the HSP sequences from GWSS to those of other insect species to help describe the relationship and history of GWSS which increases the understanding of changes in leafhopper territory and its life history.
Technical Abstract: Four heat shock protein transcripts were produced from the glassy-winged sharpshooter Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) which is the major vector of Xylella fastidiosa, the causal agent of Pierce’s disease of grapes. As genomic information has continued to be produced research on leafhopper stress responses become possible. Due to the importance of the H. vitripennis in transmission and spread of X. fastidiosa, a cDNA library was constructed from adult and fifth-instars H. vitripennis, resulting in 5,906 expressed sequence tags (ESTs). After quality scoring, 4,445 sequences underwent assembly which produced a set of 2,123 sequences that putatively represented distinct transcripts. BLASTX analysis identified 4 significant homology matches to heat shock proteins, (HSP) which are the focus of this study. The overall importance and function of HSPs lie in their ability to maintain protein integrity and activity during stressful conditions, such as extreme heat, cold, drought, or other stresses. Phylogenetic analyses using these 4 HSP sequences provided further support of transcript by the identification of specific motifs. This study shows that highly conserved genes like HSPs are a viable addition to ribosomal DNA in elucidating phylogenetic relationships.