Résumé
The phytohormone jasmonic acid (JA) and its derivatives, collectively referred to as jasmonates, regulate many developmental processes, but are also involved in response to numerous abiotic/biotic stresses. Thus far, powerful reverse genetic strategies employing perception, signaling or biosynthesis mutants have broadly contributed to our understanding of JA implication in plant stress response and development; so did the chemical gain-of-function approach based on exogenous application of the hormone. However, there is currently no method that allows for in planta tightly controlled JA production. Investigating the control of the JA synthesis pathway in bacteria-infected cotton (Gossypium hirsutum L.) plants, we identified a transcription factor (TF), namely GhERF-IIb3, that could act as positive regulator of the JA pathway. Expression of this well-conserved TF in cotton leaves was sufficient to bring about in situ JA accumulation at physiological concentrations associated with enhanced cotton defense response to bacterial infection.