OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 146/3/904    most recent pp.107.109264v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Wang, L. Articles by Baldwin, I. T. Search for Related Content PubMed PubMed Citation Articles by Wang, L. Articles by Baldwin, I. T. Agricola Articles by Wang, L. Articles by Baldwin, I. T. Related Collections Plant-Herbivore Interactions

Comparisons of LIPOXYGENASE3- and JASMONATE-RESISTANT4/6-Silenced Plants Reveal That Jasmonic Acid and Jasmonic Acid-Amino Acid Conjugates Play Different Roles in Herbivore Resistance of Nicotiana attenuata^[W],[OA]

Department of Molecular Ecology, Max-Planck-Institute for Chemical Ecology, D–07745 Jena, Germany

Whereas jasmonic acid (JA) and its amino acid conjugates, particularly JA-isoleucine (Ile), are known to play important roles in plant-herbivore interactions, whether other compounds also function as signals independently of JA-Ile and whether conjugates elicit systemic responses are unknown. To answer these questions, we simultaneously silenced JASMONATE-RESISTANT4 (JAR4) and JAR6, two functionally redundant enzymes in Nicotiana attenuata that conjugate JA to amino acids to produce plants (irjar4/6) with low levels of JA-Ile, JA-leucine (Leu), and JA-valine (Val; <16% of wild type). As expected, irjar4/6 plants are more vulnerable to herbivore attack, but only JA-Ile—not JA-Leu or JA-Val—applications restored the resistance of irjar4/6 plants, suggesting that JA-Leu and JA-Val do not mediate herbivore defense responses. Interestingly, the direct defense traits of irjar4/6 plants are significantly higher than those in LIPOXYGENASE3 (LOX3)-silenced (aslox3) plants, which are impaired in JA biosynthesis, and JA-Ile treatment could not fully restore the resistance of aslox3 plants. We thus conclude that JA, its precursors, or other metabolites complement the function of JA-Ile by eliciting a panoply of induced defenses. Similarly, transcriptional profiling of wild-type, irjar4/6, and aslox3 plants with microarrays demonstrated that JA-Ile and JA play overlapping yet distinct roles in herbivore defense. Analysis of transcripts in distal tissues demonstrated that JAR activity is essential in eliciting systemic responses. However, attempts to recover JA-¹³C₆-Ile in systemic leaves and roots after feeding wounded leaves with ¹³C₆-Ile were unsuccessful, suggesting that JA-Ile is not a long-distance signal, but is rather synthesized after the arrival of an unknown mobile signal to systemic tissues.

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.107.109264

^* Corresponding author; e-mail baldwin{at}ice.mpg.de.

Received September 16, 2007; accepted December 3, 2007; published December 7, 2007.

This article has been cited by other articles:

				G. Vandenborre, O. Miersch, B. Hause, G. Smagghe, C. Wasternack, and E. J.M. Van Damme Spodoptera littoralis-Induced Lectin Expression in Tobacco Plant Cell Physiol., June 1, 2009; 50(6): 1142 - 1155. [Abstract] [Full Text] [PDF]

				A. Paschold, G. Bonaventure, M. R. Kant, and I. T. Baldwin Jasmonate Perception Regulates Jasmonate Biosynthesis and JA-Ile Metabolism: The Case of COI1 in Nicotiana attenuata Plant Cell Physiol., August 1, 2008; 49(8): 1165 - 1175. [Abstract] [Full Text] [PDF]

				L. Katsir, A. L. Schilmiller, P. E. Staswick, S. Y. He, and G. A. Howe From the Cover: COI1 is a critical component of a receptor for jasmonate and the bacterial virulence factor coronatine PNAS, May 13, 2008; 105(19): 7100 - 7105. [Abstract] [Full Text] [PDF]

				K. Kazan and J. M. Manners Jasmonate Signaling: Toward an Integrated View Plant Physiology, April 1, 2008; 146(4): 1459 - 1468. [Full Text] [PDF]

				J. Browse and G. A. Howe New Weapons and a Rapid Response against Insect Attack Plant Physiology, March 1, 2008; 146(3): 832 - 838. [Full Text] [PDF]