| Title: | "Nicotiana attenuata MPK4 suppresses a novel jasmonic acid (JA) signaling-independent defense pathway against the specialist insect Manduca sexta, but is not required for the resistance to the generalist Spodoptera littoralis" |
| Author(s): | Hettenhausen C; Baldwin IT; Wu J; |
| Address: | "Max Planck Institute for Chemical Ecology, Jena, Germany" |
| ISSN/ISBN: | 1469-8137 (Electronic) 0028-646X (Print) 0028-646X (Linking) |
| Abstract: | "How plants tailor their defense responses to attack from different insects remains largely unknown. Here, we studied the role of a mitogen-activated protein kinase (MAPK), MPK4, in the resistance of a wild tobacco Nicotiana attenuata to two herbivores, the specialist Manduca sexta and the generalist Spodoptera littoralis. Stably transformed N. attenuata plants silenced in MPK4 (irMPK4) were generated and characterized for traits important for defense against herbivores. Only the oral secretions (OS) from M. sexta, but not the OS from S. littoralis or mechanical wounding, induced elevated levels of jasmonic acid (JA) in irMPK4 plants relative to the wild-type plants. Moreover, silencing of MPK4 strongly increased the resistance of N. attenuata to M. sexta in a fashion that was independent of COI1 (CORONATINE INSENSITIVE1)-mediated JA signaling. Untargeted metabolomic screening identified several new MPK4-dependent putative defensive compounds against M. sexta. By contrast, silencing of MPK4 did not affect the growth of the generalist insect S. littoralis, and we propose that this was because of the very low levels of fatty acid-amino acid conjugates (FACs) in S. littoralis OS. Thus, MPK4 is likely to be a key signaling element that enables plants to tailor defense responses to different attackers" |
| Keywords: | "Amino Acids/metabolism Animals Cyclopentanes/*metabolism Fatty Acids/metabolism Gene Silencing Herbivory Manduca/*physiology Metabolomics Mitogen-Activated Protein Kinases/*metabolism Models, Biological Oxylipins/*metabolism Plant Proteins/*metabolism Pri;" |
| Notes: | "MedlineHettenhausen, Christian Baldwin, Ian T Wu, Jianqiang eng 293926/ERC_/European Research Council/International Research Support, Non-U.S. Gov't England 2013/05/16 New Phytol. 2013 Aug; 199(3):787-99. doi: 10.1111/nph.12312. Epub 2013 May 15" |
