The formation of neoplasms on pea pods after egg laying by bruchid beetles is associated with the upregulation of genes inter alia encoding enzymes involved in the octadecanoid pathway. Scots pine responds to eggs laid by the pine sawfly by enhancing the transcription of sesquiterpene Olaparib IC50 synthase genes. Inducible defenses might start with the perception of in sect attack by the plants. Compounds released onto the leaves by the female insect with her eggs or substances released into plant wounds during feeding most likely convey the information indicating an insect attack, and so trigger a cascade of plant reactions, fol lowed by downstream signaling pathways that mediate specific gene expression leading to the biosynthesis of metabolites which are responsible for the direct and indir ect defenses.

It has been suggested that plants orchestrate their defense reactions against different insect herbivores by a cross talk between phytohormone pathways, with the octadecanoid signal transduction pathway playing a key role in this process. However, although jasmonic acid is known to induce indirect defenses in plants via the production of volatiles that attract egg parasi toids, the headspace profiles of egg induced plants and JA treated ones differ from each other indicating that other plant hormones are also involved in the orchestra tion of defenses that signal the presence of eggs to egg parasitoids. Herbivore eggs have been shown to induce changes in the plants primary and secondary metabolism and can cause dramatic changes in the plants transcriptome.

To date, however, only two studies of Scot pine and Brussels sprouts have addressed the role of egg induced transcriptional changes in indirect defenses. We have shown previously that elms can produce a distinct eco physiological response to the egg laying ac tivities of elm leaf beetle even in the absence of herbivory. The elegant subtlety of these responses and the co evolved species specificity predestinate this natural ecological U. minor X. luteola O. gallerucae system for studying egg induced transcriptional changes in plants. Here we present the first time a large scale study of insect egg induced defense in a natural eco logical plant insect system. For identification of egg induced genes in the field elm, five cDNA libraries were constructed from young elm trees of a single clone.

Leaves were harvested after different time periods and different treatments with feeding and or egg laying by the elm leaf beetle, artificial Brefeldin_A transfer of egg clutches, and spraying with MeJA. A total of 361,196 expressed sequence tags were pyro sequenced and assembled into unique transcripts. Here we report the comparative analysis of 21,490 Unitrans in order to detect differences in functionally annotated gene transcript abundances.