An OPR3-independent pathway uses 4,5-didehydrojasmonate for jasmonate synthesis

Autores: Chini, A.; Monte, I.; Zamarreño Arregui, Ángel; Hamberg, M.; Lassueur, S. ; Reymond, P. ; Weiss, S.; Stintzi, A.; Schaller, A.; Porzel, A. ; García-Mina Freire, José María; Solano, R. (Autor de correspondencia)
Título de la revista: NATURE CHEMICAL BIOLOGY
ISSN: 1552-4450
Volumen: 14
Número: 2
Páginas: 171 - 178
Fecha de publicación: 2018
Lugar: WOS
Biosynthesis of the phytohormone jasmonoyl-isoleucine (JA-Ile) requires reduction of the JA precursor 12-oxo-phytodienoic acid (OPDA) by OPDA reductase 3 (OPR3). Previous analyses of the opr3-1 Arabidopsis mutant suggested an OPDA signaling role independent of JA-Ile and its receptor COI1; however, this hypothesis has been challenged because opr3-1 is a conditional allele not completely impaired in JA-Ile biosynthesis. To clarify the role of OPR3 and OPDA in JA-independent defenses, we isolated and characterized a loss-of-function opr3-3 allele. Strikingly, opr3-3 plants remained resistant to necrotrophic pathogens and insect feeding, and activated COI1-dependent JA-mediated gene expression. Analysis of OPDA derivatives identified 4,5-didehydro-JA in wounded wild-type and opr3-3 plants. OPR2 was found to reduce 4,5-didehydro-JA to JA, explaining the accumulation of JA-Ile and activation of JA-Ile-responses in opr3-3 mutants. Our results demonstrate that in the absence of OPR3, OPDA enters the beta-oxidation pathway to produce 4,5-ddh-JA as a direct precursor of JA and JA-Ile, thus identifying an OPR3-independent pathway for JA biosynthesis.