Plant Dependence on Rhizobia for Nitrogen Influences Induced Plant Defenses and Herbivore Performance

Open access
Date
2014-01-21Type
- Journal Article
Abstract
Symbiotic rhizobia induce many changes in legumes that could affect aboveground interactions with herbivores. We explored how changing the intensity of Bradyrhizobium japonicum, as modulated by soil nitrogen (N) levels, influenced the interaction between soybean (Glycine max) and herbivores of different feeding guilds. When we employed a range of fertilizer applications to manipulate soil N, plants primarily dependent on rhizobia for N exhibited increased root nodulation and higher levels of foliar ureides than plants given N fertilizer; yet all treatments maintained similar total N levels. Soybean podworm (Helicoverpa zea) larvae grew best on plants with the highest levels of rhizobia but, somewhat surprisingly, preferred to feed on high-N-fertilized plants when given a choice. Induction of the defense signaling compound jasmonic acid (JA) by H. zea feeding damage was highest in plants primarily dependent on rhizobia. Differences in rhizobial dependency on soybean did not appear to affect interactions with the phloem-feeding soybean aphid (Aphis glycines). Overall, our results suggest that rhizobia association can affect plant nutritional quality and the induction of defense signaling pathways and that these effects may influence herbivore feeding preferences and performance—though such effects may vary considerably for different classes of herbivores. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000079474Publication status
publishedExternal links
Journal / series
International Journal of Molecular SciencesVolume
Pages / Article No.
Publisher
MDPISubject
Glycine max; Bradyrhizobium japonicum; Helicoverpa zea; Aphis glycines; Jasmonic acid; Rhizobia; HerbivoryOrganisational unit
03909 - Levine, Jonathan M. (ehemalig) / Levine, Jonathan M. (former)
03970 - De Moraes, Consuelo / De Moraes, Consuelo
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