Induced plant defense responses against chewing insects. Ethylene signaling reduces resistance of Arabidopsis against Egyptian cotton worm but not diamondback moth.

Published

Journal Article

The induction of plant defenses by insect feeding is regulated via multiple signaling cascades. One of them, ethylene signaling, increases susceptibility of Arabidopsis to the generalist herbivore Egyptian cotton worm (Spodoptera littoralis; Lepidoptera: Noctuidae). The hookless1 mutation, which affects a downstream component of ethylene signaling, conferred resistance to Egyptian cotton worm as compared with wild-type plants. Likewise, ein2, a mutant in a central component of the ethylene signaling pathway, caused enhanced resistance to Egyptian cotton worm that was similar in magnitude to hookless1. Moreover, pretreatment of plants with ethephon (2-chloroethanephosphonic acid), a chemical that releases ethylene, elevated plant susceptibility to Egyptian cotton worm. By contrast, these mutations in the ethylene-signaling pathway had no detectable effects on diamondback moth (Plutella xylostella) feeding. It is surprising that this is not due to nonactivation of defense signaling, because diamondback moth does induce genes that relate to wound-response pathways. Of these wound-related genes, jasmonic acid regulates a novel beta-glucosidase 1 (BGL1), whereas ethylene controls a putative calcium-binding elongation factor hand protein. These results suggest that a specialist insect herbivore triggers general wound-response pathways in Arabidopsis but, unlike a generalist herbivore, does not react to ethylene-mediated physiological changes.

Full Text

Duke Authors

Cited Authors

  • Stotz, HU; Pittendrigh, BR; Kroymann, J; Weniger, K; Fritsche, J; Bauke, A; Mitchell-Olds, T

Published Date

  • November 2000

Published In

Volume / Issue

  • 124 / 3

Start / End Page

  • 1007 - 1018

PubMed ID

  • 11080278

Pubmed Central ID

  • 11080278

Electronic International Standard Serial Number (EISSN)

  • 1532-2548

International Standard Serial Number (ISSN)

  • 0032-0889

Digital Object Identifier (DOI)

  • 10.1104/pp.124.3.1007

Language

  • eng