Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Biology, Control, and Area-Wide Management of Fruit Flies and Other Quarantine Pests

Location: Tropical Crop and Commodity Protection Research

Title: Midgut transcriptome profiling of Anoplophora glabripennis, a lignocellulose degrading Cerambycid beetle

Authors
item Scully, Erin -
item Hoover, Kelli -
item Carlson, John -
item Tien, Ming -
item Geib, Scott

Submitted to: Biomed Central (BMC) Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 22, 2013
Publication Date: December 4, 2013
Citation: Scully, E.D., Hoover, K., Carlson, J.E., Tien, M., Geib, S.M. 2013. Midgut transcriptome profiling of Anoplophora glabripennis, a lignocellulose degrading Cerambycid beetle. Biomed Central (BMC) Genomics. 14:850.

Interpretive Summary: Wood-feeding insects often work in collaboration with microbial symbionts to degrade lignin biopolymers and release glucose and other fermentable sugars from recalcitrant plant cell wall carbohydrates, including cellulose and hemicellulose. Here, we present the midgut transcriptome of larval Anoplophora glabripennis, a wood-boring beetle with documented lignin-, cellulose-, and hemicellulose- degrading capabilities, which provides valuable insights into how this insect overcomes challenges associated with feeding in woody tissue. The transcriptome represents the suite of genes expressed in the gut that allow it to feed on woody material, defend itself from defensive plant chemicals, and interact with microbes that inhabit its gut. In addition, an analysis of all herbivorous insect transcriptomes was performed to identify correlations between gene presence in insects that feed on woody substrates. This paper is the first description of a transcriptome of a beetle from the family Cerambycidae.

Technical Abstract: Background: Wood-feeding insects often work in collaboration with microbial symbionts to degrade lignin biopolymers and release glucose and other fermentable sugars from recalcitrant plant cell wall carbohydrates, including cellulose and hemicellulose. Here, we present the midgut transcriptome of larval Anoplophora glabripennis, a wood-boring beetle with documented lignin-, cellulose-, and hemicellulose-degrading capabilities, which provides valuable insights into how this insect overcomes challenges associated with feeding in woody tissue. Results and Discussion: Transcripts from putative protein coding regions of over 9,000 insect-derived genes were identified in the A. glabripennis midgut transcriptome using a combination of 454 shotgun and Illumina paired-end reads. The most highly-expressed genes predicted to encode digestive-related enzymes were trypsins, carboxylesterases, ß-glucosidases, and cytochrome P450s. Furthermore, 180 unigenes predicted to encode glycoside hydrolases (GHs) were identified and included several GH 5, 45, and 48 cellulases, GH 1 xylanases, and GH 1 ß-glucosidases. In addition, transcripts predicted to encode enzymes involved in detoxification were detected, including a substantial number of unigenes classified as cytochrome P450s (CYP6B) and carboxylesterases, which are hypothesized to play pivotal roles in detoxifying host tree defensive chemicals and could make important contributions to A. glabripennis’ expansive host range. While a large diversity of insect-derived transcripts predicted to encode digestive and detoxification enzymes were detected, few transcripts predicted to encode enzymes required for lignin degradation or synthesis of essential nutrients were identified, suggesting that collaboration with microbial enzymes may be required for survival in woody tissue. Conclusions: A. glabripennis produces a number of enzymes with putative roles in cell wall digestion, detoxification, and nutrient extraction, which likely contribute to its ability to thrive in a broad range of host trees. This system is quite different from the previously characterized termite fermentation system and provides new opportunities to discover enzymes that could be exploited for cellulosic ethanol biofuel production or the development of novel methods to control wood-boring pests.

Last Modified: 10/23/2014
Footer Content Back to Top of Page