Figure 7

Putative pathways for xylose utilization based on BLASTX annotation of transcripts sampled from the midgut microbiota of larval A. glabripennis . Xylose can be shuttled into the pentose phosphate pathway by two different routes detected in the metatranscriptome: the oxoreductive pathway and the isomerase pathway. Transcripts originating from the oxoreductive pathway were from yeasts while transcripts originating from the isomerase pathway were from lactic acid bacteria. Both pathways lead to the production of xylulose-5-phosphate, which is shuttled into the pentose phosphate pathway and is used to produce pyruvate and shikimate. These compounds serve as key intermediates in the synthesis of essential branched chain amino acids and essential aromatic amino acids, demonstrating how these wood sugars can be used by the gut microbiota to produce essential nutrients that are otherwise lacking from the A. glabripennis diet.