Transcriptional Analysis of Distant Signaling Induced by Insect Elicitors and Mechanical Wounding in Zea mays
Open Access
- 12 April 2012
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 7 (4), e34855
- https://doi.org/10.1371/journal.pone.0034855
Abstract
When plants are under insect herbivore attack defensive measures are activated not only locally, but also in distant and systemic tissues. While insect elicitors (IE) abundant in the oral secretions of the attacking herbivore are essential in the regulation of induced defenses, little is known about their effects on systemic defense signaling in maize (Zea mays). The goal of this study was therefore to identify genetic markers that can be used to further characterize local and systemic signaling events induced by IE or mechanical wounding (MW). We selected genes for this study based on their putative involvement in signaling (allene oxide synthase), regulation of gene expression (transcription factor MYC7), and in direct defenses (ribosome inactivating protein) and analyzed their expression in different sections of the treated leaf as well as in systemic parts of the same plant. We found the most significant transcript accumulation of the selected genes after treatment with insect elicitors in those parts with increased JA levels. Additionally, treatment with IE did also induce the accumulation of MYC7 transcripts in basal parts of the treated leaf and systemically. MW, in contrast, did induce RIP and AOS only locally, but not MYC7. This local suppression of MYC7 was further studied by adding glutathione (GSH) as an electron donor to MW plants to quench putative α, β-unsaturated carbonyls, which build up to significant levels around the damage site. Indeed, GSH-treated MW plants accumulated MYC7 at the damage site and also produced more volatiles, suggesting a putative redox-regulatory element being involved in the suppression of MYC7. The results presented herein provide evidence for the specific induction of distant signaling events triggered by IE, most likely through electric signaling. Additionally, a putative role for MW-induced α, β-unsaturated carbonyls in the transcriptional regulation of defense genes was discovered.This publication has 54 references indexed in Scilit:
- Plant Resistance to Insect HerbivoryPublished by Springer Science and Business Media LLC ,2011
- New Insights into Plant Responses to the Attack from Insect HerbivoresAnnual Review of Genetics, 2010
- Phytohormone-based activity mapping of insect herbivore-produced elicitorsProceedings of the National Academy of Sciences of the United States of America, 2009
- Plant Immunity to Insect HerbivoresAnnual Review of Plant Biology, 2008
- Disulfooxy fatty acids from the American bird grasshopper Schistocerca americana , elicitors of plant volatilesProceedings of the National Academy of Sciences of the United States of America, 2007
- N-(15,16-Dihydroxylinoleoyl)-glutamine and N-(15,16-epoxylinoleoyl)-glutamine isolated from oral secretions of lepidopteran larvaeTetrahedron, 2003
- Plant resistance towards insect herbivores: a dynamic interactionNew Phytologist, 2002
- Molecular Interactions between the Specialist HerbivoreManduca sexta (Lepidoptera, Sphingidae) and Its Natural Host Nicotiana attenuata. III. Fatty Acid-Amino Acid Conjugates in Herbivore Oral Secretions Are Necessary and Sufficient for Herbivore-Specific Plant ResponsesPlant Physiology, 2001
- New fatty acid amides from regurgitant of Lepidopteran (Noctuidae, Geometridae) caterpillarsTetrahedron, 1999
- An Elicitor of Plant Volatiles from Beet Armyworm Oral SecretionScience, 1997