A rationally designed JAZ subtype-selective agonist of jasmonate perception

The phytohormone 7- iso -(+)-jasmonoyl- L -isoleucine (JA-Ile) mediates plant defense responses against herbivore and pathogen attack, and thus increases plant resistance against foreign invaders. However, JA-Ile also causes growth inhibition; and therefore JA-Ile is not a practical chemical regulator of plant defense responses. Here, we describe the rational design and synthesis of a small molecule agonist that can upregulate defense-related gene expression and promote pathogen resistance at concentrations that do not cause growth inhibition in Arabidopsis . By stabilizing interactions between COI1 and JAZ9 and JAZ10 but no other JAZ isoforms, the agonist leads to formation of JA-Ile co-receptors that selectively activate the JAZ9-EIN3/EIL1-ORA59 signaling pathway. The design of a JA-Ile agonist with high selectivity for specific protein subtypes may help promote the development of chemical regulators that do not cause a tradeoff between growth and defense. The phytohormone JA-Ile can promote plant resistance against herbivores and fungal pathogens but also inhibits growth, limiting its potential use in agriculture. Here, the authors design a stereoisomer of JA-Ile analog and demonstrate that it can promote defense while having minimal impact on growth.