In vivo localization at the cellular level of stilbene fluorescence induced by Plasmopara viticola in grapevine leaves
In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent eApbigsetnreatcict mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in aAcctcivueralytegrloowcainligzaotrigoannso,f upnhdyetrosahleoxritn-s(6ish) aankdelyonfgo-r (2bedttoerr 4udn)dteerrsmtaannddinlgowth(e1i0r mroMle).anTdhihsigwho(5rk0 maMim)sdotsoesloocfaClizde, tshtirlobuegnhes,a thMeetmhyalaintiopnh-ySteonasleitxivines Aomf pglirfiacpaetvioinne.PoTlhyemocrepllhuilsamr loteccahlinziaqtuioen aonfd satinlbeimnemuflnuoocreystocleongcicealinadpupcreodacbhy, rPelasspmecotpivaerlay. vTihtiecoelxap,rethsesioangeonf tonoef mdoewmnbyer mofildtheew,CHwRaOsMdOeMteErmTHinYeLdA SinE g(CraMpTe)vfinaemillye,aaveDsNoAf mveetrhyylstruasncsefpertiabslee,, swuassceaplstioblea,ssaensdsepdartbiayllyqRreTs-PisCtaRn.t Nguecnloetayrpecshrdoumriantgininufletrcatisotnru. cLtuarseerwsacsaninnivnegstcigoantfeodcablymticraronssmcoispsyioanndelmecictrroonsmpieccrotrsocfloupoyr.imCdettrryeawtemreenutsineddutcoedacaqDuNireA UhyVp-eerxmcietethdylaautitoonfl,uaosrewseclelnacseatnhruepe--rdeigmuelantsi oionnoalf CimMaTg,eisndaincdatisnpgetchtarat doef gnroavpoevmineethlyelaavtieosn5d-i6ddianydseeadfteorcicnuorc.uMlaotiroeno.vTehr,isanhoingihnvdaossivee otefcChdniqleude toof ainvpersotgi greastisoivneinhevitveorowcahsrocmoamtipnlieztaetdiownitohf iinntveirtprohasspeecnturcolfleuioarnidmaeptroicptsotutidciefisguornespuwreersetialblseonoesbsaesrvtheediraflftueorrleosncge-tnecremistrleaargtmeleynat.ffTehceteddabtay dtheempohnysstircaotechtehmaticCadl epnevrtiurorbnsmethnet DinNvAarmioeutshylleaatifocnosmtaptaurstmthernotus.ghVisthceosinitvyowlvaesm ethnet omf aajosrppehcyifiscicomcehtehmylitcraanlsffaecrtaosre.inSfluucehnccinhgansgteilsbeanree lflinukoeredstcoenncueclienaterncshitryo,mmaotidnifyreincgonflfiugourerastcioenncleikeyileyldtobeysmtaobrleishthaanntewwo boardlaenrcseooffmeaxgpnrietussdeed./Sretrpikreinsgseddiffcehreronmceastinin. tOhveerloaclla,ltihzeatdioantaosfhsotwilbaenneepfliugoerneestcicenbcaesiisndtouctheed mbyecPh.avniitsicmoluanwdeerrelyionbgsCerdvetodxibceittywienepnlathnets.different genotypes. All inoculated genotypes displayed stilbene fluorescence in cell walls of guard cells and periclinal cell walls of eKpeiydewromradls:ce5l-lMs.etHhiyglchyetorsflinueo-arnetsibcoednyc,ecaindtmeinusmit-ystrwesasscobndsietirovne,dchirnomgautainrdre-ceolnlfigwuarlalstiotnh, aCnHRinOaMnOyMoEtThHeYrLcAoSmE,partment dDuNeA-tmoetinhyclraetiaosne,dMelothcyalaltivoins-cSoesnitsyit.ivIenAamdpdlifitcioantiosntiPlboelynmeorflpuhoisrmes(cMeSnAcPe), wPoassidfoonuiandocienaneicpaid(eL.r)mDaellilec.ell vacuoles of the susceptible genotype and in the infected spongy parenchyma of the partially resistant genotype. The very susceptible genotype was devoid of fluorescence both in the epidermal vacuoles and the mesophyll. This strongly suggests that the resistance of grapevine leaves to P. viticola is correlated with the pattern of localization of induced Isntitlbreondeuscintihoonst tissues.
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cinerea conidia (Langcake and Pryce, 1976; Langcake, 1981;
Hoos and Blaich, 1990) or of P. viticola sporangiophores and
to reduce the mobility of zoospores (Pezet et al., 1994). These
in vitro studies were an ersatz to studies on mycelia because
in vitro experiments are not possible on P. viticola mycelium,
which is an obligatory biotroph. Susceptible grapevine
species infected by P. viticola mainly produce
trans-resveratrol (3,5,4-trihydroxystilbene) and trans- and cis-piceid
(3-Ob-D-glucoside of resveratrol) (Pezet et al., 1994) whereas
resistant species produce trans-resveratrol, trans-pterostilbene
(3,5-dimethoxy-4-hydroxystilbene) and cyclic dehydrodimers
of resveratrol trans-e-viniferin and trans-d-viniferin
(Langcake, 1981; Dercks and Creasy, 1989; Pezet et al., 2003). This
result is corroborated by the fact that distinctive toxicities to
P. viticola zoospores were reported for these stilbenes (Pezet
et al., 2004a, b). The highest concentrations of viniferins
appear in resistant cultivars and they correlate with growth
inhibition of Erysiphe necator (powdery mildew) (Schnee
et al., 2008). Similarly, an inhibition of the growth of
P. viticola was observed in vivo on resistant cultivars
producing viniferins and/or pterostilbene (Alonso-Villaverde
et al., 2011). All these results suggest that stilbenes are
implicated in the resistance of grapevine to fungi. Yet, the
effect of stilbenes on mycelia of the biotrophic agent
P. viticola remains a matter of debate (Chong et al., 2009)
and obviously needs more investigation in vivo. No physical,
biochemical, or genetic evidence of the direct interaction
between plant-induced stilbenes and mycelium in situ is
currently available. Despite the lack of direct evidence, the
production of stilbenes was reported to correlate well with
resistance levels t (...truncated)