Project description:The present project deals with bark beetle gut total proteome from callow and black bark beetle, Ips typographus. The study aims to identify life stage-specific expression of gut proteins in bark beetles and their functional relevance.
Project description:The Eurasian spruce bark beetle Ips typographus is known for its devasting attack on the host tree Picea abies, a common conifer in Europe. The beetle uses various pheromone components (2-methyl-3-buten-2-ol and cis-verbenol) for mass aggregation to overcome the tree defence compounds such as terpenes. Though this aggregation pheromone biosynthesis and respective precursors via terpenes detoxification mechanism was investigated for a few decades, gene-level understanding behind these biosynthesis pathways are uncertain yet in I. typographus. Though, applying Juvenile hormone (JH III) on the beetles have induced specific pheromone biosynthesis in many bark beetle species, irrespective of their life stage, it is not uniform found in all Ips species. While investigating pheromone biosynthesis among various life stages of I. typographus, we have also reported recently about the JHIII induction of aggregation pheromone biosynthesis from the gut tissue of the beetle. Thus, in this study, we have applied the concept of JHIII induction on I. typographus and analyzed the respective pheromone and possible biosynthesis precursors from via pathway gene families from the gut tissue of the beetle. A comparative approach from transcriptome and proteome study has revealed the mevalonate pathway genes including isoprenyl-di-phosphate synthase (IPDS) gene (Ityp09271) was upregulated over 5-fold change after JHIII induction in I. typographus. The identified IPDS is suspected to directly involve in 2-methyl-3-buten-2-ol, a vital aggregation pheromone of I. typographus. Added to that, a hydrolase gene family was found upregulated over 2-fold change, specifically in the male gut tissue after JHIII treatment. Furthermore, another vital gene family, CytochromeP450 have shown the upregulated (transcript) in the male gut tissue after treatment. Especially Previously reported CyP450 candidates Ityp3140 and Ityp03153 for pheromone compounds cis/trans- verbenol and ipsdienol biosynthesis respectively. Along with CyP450 candidates, the hydrolase gene candidates could possibly involve in braking down the detox compounds such as diglycosylated terpenes and stored wax esters (verbenyl oleate) from the gut possibly provided from the of the beetle body as a reservoir. An added metabolomic analysis has confirmed these compounds abundance was in the gut tissue. Especially, the abundance of the related fatty acid ester (verbenyl oleate) has reduced half in male gut tissue after the treatment. Hence, we have shed light on three possible genes from different families for the respective pheromone and its precursors biosynthesis after JHIII application over I. typographus. This approach would lead us to elucidate the molecular basis of stored pheromone biosynthesis and the derived knowledge from this study would lead to eco-friendly pest management for this aggressive pest. Key words: Ips typographus, bark beetle, pheromone biosynthesis, de novo, Juvenile hormone treatment.
Project description:This series examines gene expression in the anterior midgut at several time points (2, 4, 8, & 16 h for males, 8 h for females) after topical application of juvenile hormone III (JHIII) or acetone (control) to adult beetles. In addition, gene expression in male anterior midguts were examined 24 h after phloem feeding or in unfed beetles. Keywords: North American pine engraver beetle; anterior midgut; juvenile hormone; pheromone biosynthesis; Coleoptera; Scolytidae Publication reference: Reference Type: Book Section Authors: Tittiger, Claus; Keeling, Christopher I.; Blomquist, Gary J. Year: 2005 Title: Some insights into the remarkable metabolism of the bark beetle midgut. Editor: Romeo, J.T. Book Title: Chemical ecology and phytochemistry of forest ecosystems City: Toronto Publisher: Elsevier Volume: 39 Pages: 57-78 Series Title: Recent Advances in Phytochemistry Keywords: other
2004-12-31 | GSE940 | GEO
Project description:Streptomyces from the bark beetle microbiome
Project description:Bark beetles (Coleoptera: Scolytinae) are pests of many forests around the world. The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is a significant pest of western North American pine forests. The MPB is able to overcome the defences of pine trees through pheromone-assisted aggregation that results in a mass attack of host trees. These pheromones, both male and female produced, are believed to be biosynthesized in the midgut and/or fat body of these insects. We have used transcriptomics (RNA-seq) to identify transcripts differentially expressed between sexes and between tissues, with juvenile hormone III treatment, which is known to induce pheromone biosynthesis.