Robustness in jasmonate signaling: mechanisms of concerted regulation and implications for crop improvement.

The jasmonate signaling pathway coordinates plant defenses and growth, thereby enhancing fitness in changing conditions. Jasmonate-mediated responses are triggered by the recognition of external signals via pattern recognition receptors (PRRs) located on the cell membrane. Following signal perception, cells rapidly activate jasmonic acid (JA) biosynthesis, resulting in the accumulation of the bioactive jasmonate, jasmonoyl-isoleucine (JA-Ile). In the nucleus, the coronatine insensitive 1-jasmonate-ZIM-domain (COI1-JAZ) complex recognizes JA-Ile and triggers JAZ ubiquitination and proteasomal degradation. Consequently, transcription factors (e.g., MYC2) bound by JAZ are released, enabling the activation and amplification of JA responses. In parallel to this activation, feedback regulation orchestrated by transcription factors terminates transcription, preventing overcommitment to JA signaling. In this review, we summarize recent advances in understanding JA signaling, emphasizing the connection between PRR activation and JA biosynthesis, and the feedback regulatory mechanisms that ensure precision and robustness of the JA signaling pathway. Finally, we discuss how these mechanistic insights can be leveraged to optimize JA signaling for crop genetic improvement.