| Title: | Effects of feeding Spodoptera littoralis on lima bean leaves: IV. Diurnal and nocturnal damage differentially initiate plant volatile emission |
| Author(s): | Arimura G; Kopke S; Kunert M; Volpe V; David A; Brand P; Dabrowska P; Maffei ME; Boland W; |
| Address: | "Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany" |
| ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
| Abstract: | "Continuous mechanical damage initiates the rhythmic emission of volatiles in lima bean (Phaseolus lunatus) leaves; the emission resembles that induced by herbivore damage. The effect of diurnal versus nocturnal damage on the initiation of plant defense responses was investigated using MecWorm, a robotic device designed to reproduce tissue damage caused by herbivore attack. Lima bean leaves that were damaged by MecWorm during the photophase emitted maximal levels of beta-ocimene and (Z)-3-hexenyl acetate in the late photophase. Leaves damaged during the dark phase responded with the nocturnal emission of (Z)-3-hexenyl acetate, but with only low amounts of beta-ocimene; this emission was followed by an emission burst directly after the onset of light. In the presence of (13)CO(2), this light-dependent synthesis of beta-ocimene resulted in incorporation of 75% to 85% of (13)C, demonstrating that biosynthesis of beta-ocimene is almost exclusively fueled by the photosynthetic fixation of CO(2) along the plastidial 2-C-methyl-D-erythritol 4-P pathway. Jasmonic acid (JA) accumulated locally in direct response to the damage and led to immediate up-regulation of the P. lunatus beta-ocimene synthase gene (PlOS) independent of the phase, that is, light or dark. Nocturnal damage caused significantly higher concentrations of JA (approximately 2-3 times) along with enhanced expression levels of PlOS. Transgenic Arabidopsis thaliana transformed with PlOS promoter :: beta-glucuronidase fusion constructs confirmed expression of the enzyme at the wounded sites. In summary, damage-dependent JA levels directly control the expression level of PlOS, regardless of light or dark conditions, and photosynthesis is the major source for the early precursors of the 2-C-methyl-D-erythritol 4-P pathway" |
| Keywords: | "Acetates/metabolism Acyclic Monoterpenes Alkenes/*metabolism Animals Carbon Isotopes/metabolism Circadian Rhythm/physiology Cyclopentanes/metabolism Erythritol/analogs & derivatives/metabolism Gene Expression Regulation, Plant Host-Parasite Interactions/*;" |
| Notes: | "MedlineArimura, Gen-ichiro Kopke, Sabrina Kunert, Maritta Volpe, Veronica David, Anja Brand, Peter Dabrowska, Paulina Maffei, Massimo E Boland, Wilhelm eng Research Support, Non-U.S. Gov't 2008/01/01 Plant Physiol. 2008 Mar; 146(3):965-73. doi: 10.1104/pp.107.111088. Epub 2007 Dec 28" |
