Jasmonate in plant defence: sentinel or double agent?

Plants and their biotic enemies, such as microbial pathogens and herbivorous insects, are engaged in a desperate battle which would determine their survival-death fate. Plants have evolved efficient and sophisticated systems to defend against such attackers. In recent years, significant progress has been made towards a comprehensive understanding of inducible defence system mediated by jasmonate (JA), a vital plant hormone essential for plant defence responses and developmental processes. This review presents an overview of JA action in plant defences and discusses how microbial pathogens evade plant defence system through hijacking the JA pathway.