Decoding Insect Feeding

Book excerpt: Nicotiana attenuata has the capacity to respond specifically to herbivory by its natural herbivore, Manduca sexta, through the perception of elicitors in larval oral secretions (OS). Fatty acid-amino acid conjugates (FACs) in the OS of the M. sexta larvae elicit the herbivory-specific responses in N.attenuata, an annual wild tobacco species. How FACs are perceived and activate signal transduction mechanisms is unknown. To find transcriptional targets of the FAC signal transduction pathway with the goal of identifying regulatory components of insect mediated responses, I used the SuperSAGE technique. I generated two SuperSAGE libraries from FAC-elicited and wounded leaf for the identification of transcripts rapidly and differentially regulated by FACs. From 12,744 unique transcript sequences identified, 429 and 117 were significantly up- and down-regulated, respectively, after FAC elicitation compared to wounding. Based on gene ontology classification, 25% of the annotated Unitags corresponded to regulatory components. qPCR analysis confirmed the FAC regulation of 70% of a subset of 27 UniTags selected. ...