NPR1 modulates cross-talk between salicylate- and jasmonate-dependent defense pathways through a novel function in the cytosol.

Published

Journal Article

Plant defenses against pathogens and insects are regulated differentially by cross-communicating signal transduction pathways in which salicylic acid (SA) and jasmonic acid (JA) play key roles. In this study, we investigated the molecular mechanism of the antagonistic effect of SA on JA signaling. Arabidopsis plants unable to accumulate SA produced 25-fold higher levels of JA and showed enhanced expression of the JA-responsive genes LOX2, PDF1.2, and VSP in response to infection by Pseudomonas syringae pv tomato DC3000, indicating that in wild-type plants, pathogen-induced SA accumulation is associated with the suppression of JA signaling. Analysis of the Arabidopsis mutant npr1, which is impaired in SA signal transduction, revealed that the antagonistic effect of SA on JA signaling requires the regulatory protein NPR1. Nuclear localization of NPR1, which is essential for SA-mediated defense gene expression, is not required for the suppression of JA signaling, indicating that cross-talk between SA and JA is modulated through a novel function of NPR1 in the cytosol.

Full Text

Duke Authors

Cited Authors

  • Spoel, SH; Koornneef, A; Claessens, SMC; Korzelius, JP; Van Pelt, JA; Mueller, MJ; Buchala, AJ; Métraux, J-P; Brown, R; Kazan, K; Van Loon, LC; Dong, X; Pieterse, CMJ

Published Date

  • March 2003

Published In

Volume / Issue

  • 15 / 3

Start / End Page

  • 760 - 770

PubMed ID

  • 12615947

Pubmed Central ID

  • 12615947

Electronic International Standard Serial Number (EISSN)

  • 1532-298X

International Standard Serial Number (ISSN)

  • 1040-4651

Digital Object Identifier (DOI)

  • 10.1105/tpc.009159

Language

  • eng