In the early sixties jasmonic acid methyl ester (JAME) was identified as the oil-constituent of jasmin, and the free acid (JA) was first found in the culture filtrate of Botryodiplodia theobromae. However, only in 1980/81 did jasmonates become interesting after Sembdner s group in Halle/Saale (Germany) observed the growth-inhibition of jasmonates and Ueda s group in Osaka (Japan) described the senescence-promoting effect of jasmonates. In the middle of the eighties the biosynthetic pathway for JA was described by Vick and Zimmermann in Fargo (USA). First, jasmonate-induced alteration of gene expression was observed with barley leaves, where several proteins accumulated abundantly upon jasmonate treatment as described by Parthier s group in Halle/Saale in 1986. Since 1990, when Ryan s lab in Pullman (USA) recognized that airborne JAME is a signal for wound-induced proteinase inhibitor gene expression in tomato, numerous sets of genes were identified as being up-regulated or down-regulated by JA. The next breakthrough was the observation in Zenk s lab in Munich (Germany) that external stimuli such as elicitors applied to plant cell suspension cultures led to an endogenous increase of jasmonates followed by alkaloid synthesis. Subsequently, JA was found to be a signal in numerous abiotic and biotic stress responses and in various developmental processes. Some of them are summarized in Figure 1. In the last decade, an enormous interest in JA has appeared, reflected in an exponentially growing number of publications. Some highlights of that period are (i) Identification of mutants of Arabidopsis affected in jasmonate biosynthesis or signalling and being male sterile. (ii) Identification of COI1 which is affected in the JA insensitive mutant coi1 as one of the first Fbox proteins of the ubiquitin/proteasome pathway found in plants (iii) The synergistic and antagonistic signalling of jasmonate, ethylene and salicylate (iv) Identification of the first transcription factors (ORCAs) that regulate JA-responsive gene expression. (v) The role of jasmonate in plant-plant and plant-insect interactions. Among other aspects, all these highlights will be discussed in the present special issue of JPGR. The most recent research on jasmonates is reviewed by experts from the corresponding fields. The 7 papers cover chemistry, physiology, molecular biology and genetics as well as applied research on jasmonates. Several aspects of JA research were reviewed in the last years. The goal of this special issue on jasmonates is to combine the numerous aspects in a parallel and new presentation. Received: 4 October 2004; accepted: 5 October 2004; Online publication: 27 January 2005 *Corresponding author; e-mail: cwastern@ipb-halle.de g ,