Caterpillar-specific gene expression in the legume, Medicago truncatula

• Published in: Plant molecular biology reporter Vol. 26; no. 1; pp. 12 - 31
• Main Authors: Darwish, S.A, Pan, L, Ide, C, Bede, J.C
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01.03.2008; Springer Nature B.V
• Subjects: Alfalfa; Amplified fragment length polymorphism; Bioinformatics; Biomedical and Life Sciences; Caterpillars; enzymes; Gene expression; Gene polymorphism; genes; glucose oxidase; Herbivores; Herbivory; insect pests; Kinases; larvae; Legumes; Life Sciences; Medicago truncatula; Metabolomics; Oxygenase; Plant Breeding/Biotechnology; plant proteins; Plant Sciences; Plant tissues; Polymerase chain reaction; Polymorphism; Protein kinase; protein kinases; Proteins; Proteomics; resistance mechanisms; Ribulose-1,5-bisphosphate; Ribulose-bisphosphate carboxylase; saliva; secretion; Secretions; Spodoptera exigua; Strictosidine synthase; cDNA-AFLP; Caterpillar; Gene expression; Legume
• ISSN: 0735-9640; 1572-9818
• DOI: 10.1007/s11105-008-0019-6

Plants adjust their defense responses to target caterpillar herbivores. Their ability to do this is, in part, based on the recognition of salivary elicitors which are secreted during insect feeding. We are interested in identifying caterpillar-specific defense responses in the model legume, Medicago truncatula Gaertn. (Fabaceae). To do this, we have taken advantage of the fact that labial salivary secretions of caterpillars of the beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae), can be impaired by cauterizing the spinneret. Plant tissues were removed within 1 h after the initiation of herbivory, and differentially expressed transcripts were identified by cDNA-amplified fragment length polymorphism (cDNA-AFLP). Gene expression patterns of five differentially expressed transcripts and one constitutive gene were verified by quantitative real time-polymerase chain reaction (qRT-PCR). Genes encoding ribulose-1,5-bisphosphate carboxylase/oxygenase activase (rubisco activase; MtRCA ), strictosidine synthase ( MtSTR ), an unknown protein ( MtUNK ), a zinc RING finger protein ( MtRFP ), and a receptor-like protein kinase ( MtRPK ) were constitutively expressed. In plants subject to mechanical damage or herbivory by caterpillars, lower expression of MtRCA , MtSTR , Mt UNK , and MtRFP was observed. In comparison, higher levels of MtRPK were expressed in a caterpillar-specific manner.