This Article Full Text (PDF) Supporting Information Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My File Cabinet Download to citation manager Request Copyright Permission Citing Articles Citing Articles via CrossRef Google Scholar Articles by Zavala, J. A. Articles by Berenbaum, M. R. PubMed PubMed Citation Articles by Zavala, J. A. Articles by Berenbaum, M. R. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CARBON DIOXIDE Social Bookmarking                What's this?

ECOLOGY
Anthropogenic increase in carbon dioxide compromises plant defense against invasive insects

Jorge A. Zavala^*,, Clare L. Casteel^*,, Evan H. DeLucia^*,, and May R. Berenbaum^*,,¶

*Institute for Genomic Biology and Departments of Plant Biology and Entomology, University of Illinois at Urbana–Champaign, Urbana, IL 61801

Contributed by May R. Berenbaum, January 22, 2008 (sent for review December 19, 2007)

Abstract

Elevated levels of atmospheric carbon dioxide (CO₂), a consequence of anthropogenic global change, can profoundly affect the interactions between crop plants and insect pests and may promote yet another form of global change: the rapid establishment of invasive species. Elevated CO₂ increased the susceptibility of soybean plants grown under field conditions to the invasive Japanese beetle (Popillia japonica) and to a variant of western corn rootworm (Diabrotica virgifera virgifera) resistant to crop rotation by down-regulating gene expression related to defense signaling [lipoxygenase 7 (lox7), lipoxygenase 8 (lox8), and 1-aminocyclopropane-1-carboxylate synthase (acc-s)]. The down-regulation of these genes, in turn, reduced the production of cysteine proteinase inhibitors (CystPIs), which are specific deterrents to coleopteran herbivores. Beetle herbivory increased CystPI activity to a greater degree in plants grown under ambient than under elevated CO₂. Gut cysteine proteinase activity was higher in beetles consuming foliage of soybeans grown under elevated CO₂ than in beetles consuming soybeans grown in ambient CO₂, consistent with enhanced growth and development of these beetles on plants grown in elevated CO₂. These findings suggest that predicted increases in soybean productivity under projected elevated CO₂ levels may be reduced by increased susceptibility to invasive crop pests.

Diabrotica virgifera | global change | Glycine max | plant–insect interactions | Popillia japonica

Author contributions: J.A.Z., C.L.C., E.H.D., and M.R.B. designed research; J.A.Z. and C.L.C. performed research; J.A.Z., C.L.C., E.H.D., and M.R.B. analyzed data; and J.A.Z., E.H.D., and M.R.B. wrote the paper.

Present address: Consejo Nacional de Investigaciones Científicas y Técnicas, Catedra de Produccion Vegetal, Facultad de Agronomia, University of Buenos Aires, Avenida San Martin 4453, Buenos Aires, Argentina.

The authors declare no conflict of interest.

^¶To whom correspondence should be addressed. E-mail: maybe{at}uiuc.edu

© 2008 by The National Academy of Sciences of the USA

CiteULike    Complore    Connotea    Del.icio.us    Digg    What's this?

Current Issue | Archives | Online Submission | Info for Authors | Editorial Board | About Subscribe | Advertise | Contact | Site Map Copyright © 2008 by the National Academy of Sciences