Jasmonic acid induces trichome formation in Arabidopsis leaves via the receptor CORONATINE INSENSITIVE 1, and crosstalk with specific auxin signaling components and cell patterning genes

Trichomes are leaf epidermal cells with important adaptive functions and represent useful systems for studying cell fate determination. Jasmonic acid (JA) and auxin (indole-3-acetic acid; IAA) share signaling elements that influence growth and development, but their roles in epidermal cell differentiation in leaves have been scarcely investigated. In this work, we show that trichome formation was stimulated in a JA concentration-dependent manner in leaves of Arabidopsis seedlings, but not in JA resistant coi1-1 mutants defective on the JA receptor CORONATINE INSENSITIVE 1, or in auxin signaling double mutant arf7/arf19 or cell specification mutants gl2 and rhd6. Noteworthy, jasmonic acid-related mutants jar1 and axr1-3 as well as the triple mutant tir1/afb2/afb3 defective in auxin receptors and slr1, displayed normal responses to trichome formation induced by jasmonic acid. Our results indicate that the jasmonic acid receptor CORONATINE INSENSITIVE 1 mediates leaf epidermal cell differentiation likely acting in concert with ARF7 and ARF19, GL2 and RHD6 transcription factors.