Jasmonic acid (JA) and its volatile methyl ester (MeJA) belong to a family of lipid-derived signalling molecules that affect many aspects of plant life, including defense against certain pathogens and insects and some developmental processes. JA signal transduction leads to modulation of the expression of primary response genes, the product of which lead to the expression of secondary response genes. The ORCA3 transcription factor fromCatharanthus roseus is a good candidate for a terminal component of the JA signal transduction pathway. To our knowledge, not a single component of the primary JA signal transduction pathway has been characterized to date inArabidopsis. Many transcriptional components of secondary JA response pathways have been described in this model plant species, and are reviewed here. Our review advocates a strong adherence to signal transduction terminology as employed in the animal research field and in molecular biology textbooks, to simplify and correct current models about JA signal transduction leading to gene expression.