Jasmonate signalling network in Arabidopsis thaliana: crucial regulatory nodes and new physiological scenarios

Summary Plant development and stress responses are regulated by complex signalling networks that mediate specific and dynamic plant responses upon activation by various types of exogenous and endogenous signal. In this review, we focus on the latest published work on jasmonate (JA) signalling components and new regulatory nodes in the transcriptional network that regulates a number of diverse plant responses to developmental and environmental cues. Not surprisingly, the majority of the key revelations in the field have been made in Arabidopsis thaliana . However, for comparative reasons, we integrate information on Arabidopsis with recent reports for other plant species (when available). Recent findings on the regulation of plant responses to pathogens by JAs, as well as new evidence implicating JAs in the regulation of senescence, suggest a common mechanism of JA action in these responses via distinct groups of transcription factors. Moreover, a significant increase in the amount of evidence has allowed placing of specific mitogen‐activated protein kinases (MAPKs) as crucial regulatory nodes in the defence signalling network. In addition, we report on new physiological scenarios for JA signalling, such as organogenesis of nitrogen‐fixing nodules and anticancer therapy. Contents Summary 1 I. Introduction 2 II. Key players in the jasmonate biosynthetic and signalling pathways 2 III. High‐throughput studies add new elements to stress‐activated signalling networks 6 IV. Novel contribution of kinase cascades to cross‐talk between jasmonate and other defence‐signalling pathways 8 V. Jasmonates and senescence 10 VI. New physiological scenarios for jasmonates 11 VII. Conclusions and perspectives 13 Acknowledgements 13 References 13