Bacteria-triggered systemic immunity in barley is associated with WRKY and ETHYLENE RESPONSIVE FACTORs but not with salicylic acid.

Abstract

Leaf-to-leaf systemic immune signaling known as systemic acquired resistance is poorly understood in monocotyledonous plants. Here, we characterize systemic immunity in barley (Hordeum vulgare) triggered after primary leaf infection with either Pseudomonas syringae pathovar japonica (Psj) or Xanthomonas translucens pathovar cerealis (Xtc). Both pathogens induced resistance in systemic, uninfected leaves against a subsequent challenge infection with Xtc. In contrast to systemic acquired resistance in Arabidopsis (Arabidopsis thaliana), systemic immunity in barley was not associated with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 or the local or systemic accumulation of salicylic acid. Instead, we documented a moderate local but not systemic induction of abscisic acid after infection of leaves with Psj. In contrast to salicylic acid or its functional analog benzothiadiazole, local applications of the jasmonic acid methyl ester or abscisic acid triggered systemic immunity to Xtc. RNA sequencing analysis of local and systemic transcript accumulation revealed unique gene expression changes in response to both Psj and Xtc and a clear separation of local from systemic responses. The systemic response appeared relatively modest, and quantitative reverse transcription-polymerase chain reaction associated systemic immunity with the local and systemic induction of two WRKY and two ETHYLENE RESPONSIVE FACTOR (ERF)-like transcription factors. Systemic immunity against Xtc was further associated with transcriptional changes after a secondary/systemic Xtc challenge infection; these changes were dependent on the primary treatment. Taken together, bacteria-induced systemic immunity in barley may be mediated in part by WRKY and ERF-like transcription factors, possibly facilitating transcriptional reprogramming to potentiate immunity.

• Authors: Sanjukta Dey, Marion Wenig, Gregor Langen, Sapna Sharma, Karl G Kugler, Claudia Knappe, Bettina Hause, Marlies Bichlmeier, Valiollah Babaeizad, Jafargholi Imani, Ingar Janzik, Thomas Stempfl, Ralph Hückelhoven, Karl-Heinz Kogel, Klaus F X Mayer, A Corina Vlot
• Journal: Plant physiology (Plant Physiol) Vol. 166 Issue 4 Pg. 2133-51 (Dec 2014) ISSN: 1532-2548 [Electronic] United States
• PMID: 25332505 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 American Society of Plant Biologists. All Rights Reserved.

Chemical References

• Acetates
• Cyclopentanes
• Ethylenes
• Oxylipins
• Plant Growth Regulators
• Thiadiazoles
• benzo-1,2,3-thiadiazole
• Abscisic Acid
• methyl jasmonate
• ethylene
• Salicylic Acid

Topics

• Abscisic Acid (pharmacology)
• Acetates (pharmacology)
• Cyclopentanes (pharmacology)
• Ethylenes (pharmacology)
• Hordeum (drug effects, genetics, immunology)
• Oxylipins (pharmacology)
• Plant Diseases (immunology, microbiology)
• Plant Growth Regulators (pharmacology)
• Plant Immunity
• Plant Leaves (drug effects, genetics, immunology)
• Pseudomonas syringae (physiology)
• Salicylic Acid (pharmacology)
• Thiadiazoles (pharmacology)
• Xanthomonas (physiology)