Fig 1.
The fungal pathogen Magnaporthe oryzae chemically disables the jasmonic acid (JA)–mediated defense signaling in rice.
M. oryzae secretes the antibiotic biosynthesis monooxygenase (Abm) and its endogenously produced chemical effector 12-hydroxy jasmonic acid (12OH-JA) in a biphasic manner to suppress host immunity during establishment of the blast disease in rice. Loss of Abm function leads to activation of the host defense via jasmonate signaling and consequently blocks fungal invasion in rice plants. Brownish orange inclusions depict the sites of methyl JA-induced innate immunity that blocks the abmΔ strain of M. oryzae in the first invaded rice cell. A, appressorium; C, conidium; IH, invasive hypha; JA-Ile, isoleucine conjugate of JA; Jaz9, jasmonate-ZIM domain repressor protein 9; MeJA, methyl JA; WT, wild-type M. oryzae. Hypothetical receptors or transporters for the fungal JA derivatives have been depicted on the host cell surface. The schematic has not been drawn to scale.