| Title: | Herbivore induction of jasmonic acid and chemical defences reduce photosynthesis in Nicotiana attenuata |
| Author(s): | Nabity PD; Zavala JA; DeLucia EH; |
| Address: | "Department of Plant Biology and Institute of Genomic Biology, University of Illinois, Urbana, IL, USA" |
| ISSN/ISBN: | 1460-2431 (Electronic) 0022-0957 (Print) 0022-0957 (Linking) |
| Abstract: | "Herbivory initiates a shift in plant metabolism from growth to defence that may reduce fitness in the absence of further herbivory. However, the defence-induced changes in carbon assimilation that precede this reallocation in resources remain largely undetermined. This study characterized the response of photosynthesis to herbivore induction of jasmonic acid (JA)-related defences in Nicotiana attenuata to increase understanding of these mechanisms. It was hypothesized that JA-induced defences would immediately reduce the component processes of photosynthesis upon attack and was predicted that wild-type plants would suffer greater reductions in photosynthesis than plants lacking JA-induced defences. Gas exchange, chlorophyll fluorescence, and thermal spatial patterns were measured together with the production of defence-related metabolites after attack and through recovery. Herbivore damage immediately reduced electron transport and gas exchange in wild-type plants, and gas exchange remained suppressed for several days after attack. The sustained reductions in gas exchange occurred concurrently with increased defence metabolites in wild-type plants, whereas plants lacking JA-induced defences suffered minimal suppression in photosynthesis and no increase in defence metabolite production. This suppression in photosynthesis occurred only after sustained defence signalling and defence chemical mobilization, whereas a short bout of feeding damage only transiently altered components of photosynthesis. It was identified that lipoxygenase signalling interacted with photosynthetic electron transport and that the resulting JA-related metabolites reduced photosynthesis. These data represent a metabolic cost to mounting a chemical defence against herbivory and link defence-signalling networks to the differential effects of herbivory on photosynthesis in remaining leaf tissues in a time-dependent manner" |
| Keywords: | Animals Chlorophyll/metabolism Cyclopentanes/*metabolism Down-Regulation Herbivory/*physiology *Host-Parasite Interactions Lipoxygenase/genetics/metabolism Manduca/*physiology Oxylipins/*metabolism *Photosynthesis Plant Proteins/genetics/metabolism Tobacc; |
| Notes: | "MedlineNabity, Paul D Zavala, Jorge A DeLucia, Evan H eng England 2012/12/25 J Exp Bot. 2013 Jan; 64(2):685-94. doi: 10.1093/jxb/ers364. Epub 2012 Dec 21" |
