Title: | UVR8 mediates UV-B-induced Arabidopsis defense responses against Botrytis cinerea by controlling sinapate accumulation |
Address: | "IFEVA, Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad de Buenos Aires, Ave. San Martin 4453, C1417DSE, Buenos Aires, Argentina" |
ISSN/ISBN: | 1752-9867 (Electronic) 1674-2052 (Linking) |
Abstract: | "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 (jar1-1 and P35S:JAZ10.4) or metabolism of tryptophan-derived defense compounds (pen2-1, pad3-1, 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 tt4-1, a mutant deficient in chalcone synthase and therefore impaired in the synthesis of flavonoids, but was absent in fah1-7, a mutant deficient in ferulic acid 5-hydroxylase, which is essential for sinapate biosynthesis. Collectively, these results indicate that UVR8 plays an important role in mediating the effects of UV-B radiation on pathogen resistance by controlling the expression of the sinapate biosynthetic pathway" |
Keywords: | "Arabidopsis/genetics/*immunology/*microbiology/radiation effects Arabidopsis Proteins/*metabolism Botrytis/drug effects/*physiology/radiation effects Chromosomal Proteins, Non-Histone/*metabolism Coumaric Acids/chemistry/*metabolism Cyclopentanes/pharmaco;" |
Notes: | "MedlineDemkura, Patricia V Ballare, Carlos L eng Research Support, Non-U.S. Gov't England 2012/03/27 Mol Plant. 2012 May; 5(3):642-52. doi: 10.1093/mp/sss025. Epub 2012 Mar 23" |