| Title: | Insect herbivores selectively suppress the HPL branch of the oxylipin pathway in host plants |
| Author(s): | Savchenko T; Pearse IS; Ignatia L; Karban R; Dehesh K; |
| Address: | "Department of Plant Biology, University of California, Davis, CA 95616, USA" |
| ISSN/ISBN: | 1365-313X (Electronic) 0960-7412 (Linking) |
| Abstract: | "Insect herbivores have developed a myriad of strategies to manipulate the defense responses of their host plants. Here we provide evidence that chewing insects differentially alter the oxylipin profiles produced by the two main and competing branches of the plant defensive response pathway, the allene oxide synthase (AOS) and hydroperoxide lyase (HPL) branches, which are responsible for wound-inducible production of jasmonates (JAs), and green leafy volatiles (GLVs) respectively. Specifically, we used three Arabidopsis genotypes that were damaged by mechanical wounding or by insects of various feeding guilds (piercing aphids, generalist chewing caterpillars and specialist chewing caterpillars). We established that emission of GLVs is stimulated by wounding incurred mechanically or by aphids, but release of these volatiles is constitutively impaired by both generalist and specialist chewing insects. Simultaneously, however, these chewing herbivores stimulated JA production, demonstrating targeted insect suppression of the HPL branch of the oxylipin pathway. Use of lines engineered to express HPL constitutively, in conjunction with quantitative RT-PCR-based expression analyses, established a combination of transcriptional and post-transcriptional reprogramming of the HPL pathway genes as the mechanistic basis of insect-mediated suppression of the corresponding metabolites. Feeding studies suggested a potential evolutionary advantage of suppressing GLV production, as caterpillars preferably consumed leaf tissue from plants that had not been primed by these volatile cues" |
| Keywords: | "Aldehyde-Lyases/genetics/*metabolism Animals Aphids/*physiology Arabidopsis/enzymology/genetics/*physiology Butterflies/*physiology Cyclopentanes/metabolism Cytochrome P-450 Enzyme System/genetics/*metabolism Gene Expression Profiling Genes, Plant *Herbiv;" |
| Notes: | "MedlineSavchenko, Tatyana Pearse, Ian S Ignatia, Laura Karban, Richard Dehesh, Katayoon eng Research Support, U.S. Gov't, Non-P.H.S. England 2012/11/09 Plant J. 2013 Feb; 73(4):653-62. doi: 10.1111/tpj.12064. Epub 2012 Dec 28" |
