IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
UVR8 mediates UV-B-induced Arabidopsis defense responses against Botrytis cinerea by controlling sinapate accumulation.
Autor/es:
DEMKURA PV; BALLARÉ CL
Revista:
MOLECULAR PLANT
Editorial:
OXFORD UNIV PRESS
Referencias:
Lugar: Oxford; Año: 2012 vol. 3 p. 642 - 652
ISSN:
1674-2052
Resumen:
Light is emerging as a central regulator of plant immune responses against herbivores and pathogens. Solar UV-B radiation plays an important role as a positive modulator of plant defense. However, since UV-B photons can interact with a wide spectrum of molecular targets in plant tissues, the mechanisms that mediate their effects on plant defense have remained elusive. Here we show that ecologically meaningful doses of UV-B radiation increase Arabidopsis resistance to the necrotrophic fungus Botrytis cinerea and that this effect is mediated by the photoreceptor UVR8. The UV-B effect on plant resistance was conserved in mutants impaired in jasmonate (JA) signaling (jar1 and P35S:JAZ10.4) or metabolism of tryptophan-derived defense compounds (pen2, pad3, pen2 pad3), suggesting that neither regulation of the JA pathway nor changes in levels of indolic glucosinolates (iGS) or camalexin are involved in this response. UV-B radiation, acting through UVR8, increased the levels of flavonoids and sinapates in leaf tissue. The UV-B effect on pathogen resistance was still detectable in tt4, a mutant deficient in chalcone synthase and therefore impaired in the synthesis of flavonoids, but was absent in fah1, a mutant deficient in ferulic acid 5-hydroxylase, which is essential for sinapate biosynthesis. Collectively, these results indicate that UVR8 plays an important role mediating the effects of UV-B radiation on pathogen resistance by controlling the expression of the sinapate biosynthetic pathway.