A rapid wound signal activates the systemic synthesis of bioactive jasmonates in Arabidopsis.
Jasmonic acid (JA) and its biologically active derivatives (bioactive JAs) perform a critical role in regulating plant responses to wound stress. The perception of bioactive JAs by the F-box protein COI1 triggers the SCF(COI1)/ubiquitin-dependent degradation of JASMONATE ZIM-DOMAIN (JAZ) proteins that repress the expression of JA-response genes. JA is required for many wound-inducible systemic defense responses, but little is known about the role of the hormone in long-distance signal relay between damaged and undamaged leaves. Here, we show that the wounding of Arabidopsis thaliana leaves results in the rapid (<5 min) accumulation of jasmonoyl-l-isoleucine (JA-Ile), the bioactive form of JA, in leaves distal to the wound site. The rapid systemic increase in JA-Ile preceded the onset of early transcriptional responses, and was associated with JAZ degradation. Wound-induced systemic production of JA-Ile required the JA biosynthetic enzyme 12-oxo-phytodienoic acid (OPDA) reductase 3 (OPR3) in undamaged responding leaves, but not in wounded leaves, and was largely dependent on the JA-conjugating enzyme JAR1. Interestingly, the wound-induced synthesis of JA/JA-Ile in systemic leaves was correlated with a rapid decline in OPDA levels. These results are consistent with a model in which a rapidly transmitted wound signal triggers the systemic synthesis of JA, which, upon conversion to JA-Ile, activates the expression of early response genes by the SCF(COI1)/JAZ pathway.
Koo
Abraham J K
AJ
Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
Gao
Xiaoli
X
Jones
A Daniel
AD
Howe
Gregg A
GA
D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D009713:Nucleotidyltransferases / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism; D015398:Signal Transduction; D010453:Peptide Synthases
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D007532:Isoleucine; D009713:Nucleotidyltransferases; D010088:Oxidoreductases; D054883:Oxylipins; D018749:RNA, Plant; C112279:COI1 protein, Arabidopsis; C532883:jasmonoyl-isoleucine; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; C416525:OPR3 protein, Arabidopsis; C412831:AT2G46370 protein, Arabidopsis; D010453:Peptide Synthases