Evaluation of TMV Lesion Formation and Timing of Signal Transduction during Induction of Systemic Acquired Resistance (SAR) in Tobacco with a Computer-Assisted Method

Nicotiana tabacum L. cv. Xanthi nc plants were inoculated with tobacco mosaic virus (TMV) in order to develop a method for evaluation of lesion size and its distribution characteristics during the induction of systemic acquired resistance (SAR). All necrotic lesions were scored with an image analysis software and subjected to statistical analysis. The diminished lesion size and its right-skewed, non-normal distribution seem to be an important feature of SAR response. The results showed that the degree of induced resistance differs according to the position of the leaf on the plant’s shoot. In order to detect the timing of signal transduction from TMV infected leaves to distant ones, the infected leaves were removed from the tobacco plants at different time intervals. When the infected leaves were removed after 4 days, the SAR was always induced on the distant leaves indicating complete signal transduction within 4 days

Effect of Artificial Light Conditions on Local and Systemic Resistance Response of Tobacco to TMV Infection

Systemic acquired resistance (SAR) is effectively inducible in greenhouse and certain artificial light sources cause non-optimal growth of tobacco plants. Therefore, the morphological characteristics, local and systemic resistance response of N. tabacum cv. ‘Xanthi’ nc plants (harbouring NN resistance genes) to tobacco mosaic virus (TMV) infection under three artificial light sources with different spectral distribution were compared with greenhouse conditions. Statistical analysis of data was carried out by R package (R Core Team, 2015). Generally, artificial light sources (especially fluorescent tube, and halogen lamp) decreased the local resistance response and caused substantial morphological and developmental differences as compared to greenhouse conditions when plants were kept during their entire life (lifelong experimental regime) under these conditions. On the contrary, no or much less differences were found when plants were transferred from greenhouse to artificial light sources only at six leaf stage (short experimental regime). While induction of systemic acquired resistance (SAR) frequently decreased TMV lesion size by about 50-60% under greenhouse conditions, two of the three artificial light sources, fluorescent tube and halogen lamp were substantially and significantly less effective under short experimental regime conditions (25-35%). A metal halide light source with similarity to sunshine’s spectral distribution, however, partially mimicked the effect of greenhouse conditions indicating the importance of light spectrum among other factors in SAR induction and prevention of distorted growth of plants. Consequently, the optimization of the effect of artificial light sources is an important factor in experimental design studying signal transduction and biochemistry of SAR.</jats:p

A transz-rezveratrol és rokonvegyületek vizsgálata BioAréna-rendszerben

A vörös bor kedvező biológiai hatásaiért elsősorban a kékszőlő termés héjából a vörösborba kerülő sztilbénvázas transz-rezverátrol (TR) a felelős. A TR sokrétű hatásának értelmezése a hatás mechanizmus teljesen uj megközelítését igényelte. Feltételeztük korábban, majd bizonyítottuk , hogy egyrészt az antibiotikus hatású TR-rel együtt a szőlőnövényben a formaldehid (HCHO)kötött formában együttesen fordul elő, másrészt kémiai reakciókban pedig bizonyitottuk hogy a TR reakcióba lép a HCHO-val, amikor nagyon reaktiv hidroximetil-származékok képződnek.Az elmult időszakban a TR és a HCHO közötti reakciókat mikrokémiai szinten tanulmányoztuk. Az un BioAréna rendszer (a direkt bioautográfia továbbfejlesztett változata és a müveleti lépések koordinálása) lehetővé tette a TR és a HCHO közötti reakciók szisztematikus tanulmányozását. Megállapítottuk, hogy a TR kettős hatást ad, melynek első lépése a HCHO molekulák felvétele az adott rendszerből, s ez önmagában biológiai (védő) hatást jelent. Az igy keletkezett uj hidroximetil TR származékok antiproliferativ hatást mutatnak (pl. mikrobák és tumor sejtek ellen).Ozon-befogó molekulák adásával nem tudtuk a TR antibakteriális hatását csökkenteni. A BioAréna-rendszerben különböző hazai és külföldi fehér és vörös borfajták antibakteriális spektrumát is összehasonlitottuk: a fehér borfajták általában mérsékelt antibiotikus hatásukkal tüntek ki minőségi és mennyiségi szinten egyaránt.. | For the beneficial activities of red wine mainly a stilbene derivative, trans-resveratrol (TR) which is originating from the skin of red grapes into the red wine, is responsible. The explanation of the multiple biological activity of TR required a totally new approach to the mechanism of action. We supposed earlier and then proved that the TR in the grape plant occurs together with bound formaldehyde (HCHO) and we proved in chemical reactions that TR can react with HCHO forming very reactive hydroxymethyl derivatives. More recently the interaction between TR and HCHO can be studied in microchemical level: the BioArena system (the developed version of direct bioautography and the coordination of operating steps) gave a possibility for the systematic study of the interactions between TR and HCHO . It has been established that TR generates a double effect. The mobilisation of HCHO from a given biological unit (e.g. tissue) with TR (first step) may cause a chemopreventive /biological effect and the reaction products (hydroxymethyl derivatives) between TR and HCHO (second step) may exert a killing/inhibiting effects on pathogens and/or cancer cells (double effect). Using ozone (O3) capture molecules (e.g. limonene) in the chromatographic spots the antibacterial activity of TR didn't decrease. Comparison of antibacterial activity of white and red wines showed the moderate antibacterial activity of white wines quantitatively and qualitatively, alike.

Gazdaságilag jelentős lisztharmatgombafajok eredete, életciklusa és egyéb vonatkozásai = Origin, life cycle and other aspects of some economically important powdery mildew fungi

A projekt szerteágazó kutatásokat foglalt magában, melyek a lisztharmatgombákkal (Erysiphales), számos gazdaságilag jelentős ill. vadon élő növényfaj jelentős kórokozóival kapcsolatosak. A fontosabb eredmények a következők: (a) első alkalommal jellemeztük komplex módon a paradicsomlisztharmattal szembeni növényi rezisztencia-mechanizmusokat, (b) feltártuk a paprikalisztharmat-fertőzés minden lépését, (c) tisztáztuk az "őszibarack rozsdás foltossága" betegség etiológiáját és meghatároztuk az ellene alkalmazható növényvédelmi kezelés időpontját, (d) kimutattunk egy új sporulációs mechanizmust, az ún. mikrociklikus konidiogenezist számos lisztharmatgombafajban, (e) első alkalommal mutattuk ki paralóg rDNS ITS szekvenciák előfordulását lisztharmatgombákban, (f) meghatároztuk az egyes lisztharmatgombafajok konídiumaiban előforduló fibrozintestek kémiai összetételét, (g) megállapítottuk, hogy a strobilurin-rezisztencia molekuláris markere széles körben elterjedt a hazai szőlő-, alma- és paprikalisztharmat-populációkban, (h) feltártuk az almalisztharmat életciklusának több, eddig ismeretlen részletét. | The project consisted of various studies on powdery mildew fungi (Erysiphales), widespread pathogens of many economically important crops and wild plant species. The most important results are (a) a complex characterization of plant resistance to powdery mildew in tomato, (b) detection of all the steps of powdery mildew infection in pepper, (c) clarification of the etiology of peach rusty spot and timing fungicide treatments against this disease, (d) detection of microcyclic conidiogenesis, a new sporulation mechanism, in several powdery mildew species, (e) first detection of paralogue rDNA ITS sequences in powdery mildews, (f) elucidation of the chemical composition of fibrosin bodies present in conidia of a number of powdery mildew species, (g) detection of the molecular marker of strobilurin resistance in most Hungarian populations of grapevine, apple and pepper powdery mildew fungi, (h) description of new elements of the life cycle of apple powdery mildew

Metilviologén (paraquat) toleráns nyárfaklónok (Populus x canescens) szelekciója és alkalmazása fitoremediációban

Paraquat (syn.: metilviologén) toleráns nyárfa (Populus x canescens) klónok szelekcióját végeztük el in vitro kultúrában. A szintetikus talaj összetétele: WPM (Woody Plant Media) tápsók, 1% szacharóz, 0,8 % agar 1 mg/l benziladenin, 0,2 mg/l naftilecetsav és paraquat koncentráció sor (2×10(-6) M, 1,47×10(-6) M, 9,3×10(-7) M, 4×10(-7) M) volt. A regeneránsokat szelekciós táptalajon történő tesztelés után felszaporítottuk (mikroszaporítás), gyökeresítettük, majd üvegházban felneveltük. A molekuláris (RTqPCR) és biokémiai elemzések (aszkorbát peroxidáz, glutation peroxidáz, glutation Stranszferáz, lipoxigenáz) igazolták egy rendkívül stabil paraquat toleráns klón sikeres szelekcióját. A klónokat az in vitro vizsgálatokat követően in situ (Fűzfőgyártelep) teszteljük gyomirtószer maradványok toleranciájára. | Paraquat (syn.: methylviologen) tolerant poplar (P. x canescens) clones (PQT) were selected in in vitro cultures at concentration series of paraquat (2×10(-6) M, 1.47×10(-6) M, 9.3×10(-7) M, 4×10(-7) M). After testing on tissue culture media, regenerants were micropropagated. After rooting, PQT-clones were transplanted to a greenhouse. PQT clones showed significantly higher gst gene expression then wild type (WT) analyzed by RT-qPCR (quantitative reverse transcriptase PCR). For functional analysis enzyme activities of GST (glutathione S-transferase), APOX (ascorbate peroxides), GR (glutathione reductase), and LOX (lipoxygenase, pH 8.0) were determined. After rooting, PQT-clones were transplanted in glass houses, followed by field performance analyses for phytoremediation (environmental clean up using plants) capacity in heavily contaminated area at Balatonfűzfő, Hungar

Protective role of S-methylmethionine-salicylate in maize plants infected with Maize dwarf mosaic virus

This study aimed to detect the harmful effects of Maize dwarf mosaic virus (MDMV) infection, and to demonstrate the potential benefits of S-methylmethionine-salicylate (MMS) pretreatment in infected maize (Zea mays L.) plants. The results of chlorophyll a fluorescence measurements showed that in MDMV-infected plants additional quenchers of fluorescence appear, probably as the result of associations between the virus coat protein and thylakoid membranes. It is important to note that when infected plants were pretreated with MMS, such associations were not formed. MDMV infection and MMS pretreatment resulted in a decrease in ascorbate peroxidase (APX) activity in maize leaves, while infection contributed to an increase in activity in the roots. Infection raised the guaiacol peroxidase (GPX) enzyme activity level, which was reduced by MMS pretreatment. MMS contributed to a decrease in both the RNA and coat protein content of MDMV, to an equal extent in maize leaves and roots. The results showed that MMS pretreatment enhanced the stress response reactions against MDMV infection in maize plants and retarded the spreading of infection

A gst gén DNS-demetilált overexpressziója a szürkenyár (Populus x canescens) fitoremediációs kapacitásának növelésére

A szürkenyár (Populus x canescens) gst (glutation S-transzferáz) génexpresszióját növeltük meg DHAC-indukált (5,6-dihidro-5'-azacitidin hidroklorid) DNSdemetilációval. Három klónt vizsgáltunk, a természetes (WT) és két glutationtúltermelő 35S-gshI nyárfaklónt (11ggs, 6lgl) RT-qPCR elemzésben. A gst gén megemelt expressziós szintje a DHAC-kezelt kontroll növényekben 4,9-szeresre emelkedett, amely tovább nőtt paraquat stresszben (11,2-szeres), amely eredmény azt bizonyítja, hogy a DNS demetilációjával az endogén gének expressziós szintje nagyságrendekkel emelhető meg. Ismert, hogy a DNS demetiláció a vegetativ klónokban öröklődik (epigenetikus memória), ezért a demetilációs eljárás (gén upreguláció) új lehetőséget ad stressztűrő nyárfaklónok előállítására. | In the study presented gst (glutathione S-transferase) gene expression levels of poplar (Populus x canescens) were analyzed in response to the DNA demethylating agent DHAC (5,6-dihydro-5'-azacytidine hydrochloride). Aseptic leaf discs cultures of wild type (WT) and two gshI-transgenic clones (6lgl and 11ggs) clones were analyzed by RT-qPCR. High expression levels of DHAC treated control plants (4.9-fold increment, and a further 11.2-fold increment after paraquat treatment) proves that DNA demethylation provides powerful tools in gene-upregulation. As DNA methylation patterns are inherited (‘epigenetic memory’) novel poplar plant sources are provided with increased gst gene expression levels

Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography

A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)

Detection of Lipid Peroxidation-Derived Free Azelaic Acid, a Biotic Stress Marker and Other Dicarboxylic Acids in Tobacco by Reversed-Phase HPLC-MS Under Non-derivatized Conditions

Azelaic acid (AzA, 1,9-nonadienoic acid) is a nine-carbon chain (C9 ) dicarboxylic acid with multiple and diverse functions in humans and plants. In plants this compound was suggested as a marker for lipid peroxidation under biotic and abiotic stress conditions and an inducer (priming agent) of plant immunity (acquired resistance). Detection methods for AzA in plants include a wide range of methodological approaches. This new and simple reversed-phase HPLC-MS protocol describes the measurement of AzA and other dicarboxylic acids either from tobacco leaf tissue or petiolar exudates (vascular sap) of plants under non-derivatized conditions