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Frederick Meins - One of the best experts on this subject based on the ideXlab platform.
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The function of vacuolar β-1,3-glucanase investigated by antisense transformation. Susceptibility of transgenic Nicotiana sylvestris plants to Cercospora Nicotianae infection
Plant Molecular Biology, 1992Co-Authors: Jean-marc Neuhaus, Susan Flores, Dennis Keefe, Patricia Ahl-goy, Frederick MeinsAbstract:Vacuolar class I β-1,3-glucanases (EC 3.2.1.39) are believed to be important in the induced defense reaction of plants to fungal infection. We used antisense transformation to test this hypothesis and to identify other possible physiological functions of this enzyme. Nicotiana sylvestris plants were transformed with antisense constructions containing the region from position 27 to 608 of the coding sequence of the basic, vacuolar β-1,3-glucanase gene GLA of tobacco regulated by cauliflower mosaic virus 35S RNA expression signals. Plants homozygous for this transgene showed a marked, ca. 20-fold reduction in the constitutive expression of class I β-1,3-glucanase antigen in their leaves. RNA blot analysis indicated that the antisense plants expressed low levels of the sense transcript of the host β-1,3-glucanase gene and the antisense transcript of the transgene. Immune blot analysis of plant extracts indicated that only expression of the N. sylvestris homologue of class I tobacco β-1,3-glucanase and not the acidic, class II isoforms of the enzyme was blocked in the antisense plants. Class I isoforms of β-1,3-glucanase and chitinase were coordinately induced in leaves of untransformed and empty-vector-transformed N. sylvestris plants treated with ethylene or infected with the fungal leaf pathogen Cercospora Nicotianae . In antisense plants, chitinase but not β-1,3-glucanase was induced under these conditions indicating that antisense transformation effectively blocks constitutive as well as induced expression of class I β-1,3-glucanase. Under greenhouse conditions, antisense plants developed normally and were fertile. The plants did not exhibit increased susceptibility to C. Nicotianae infection. These results suggest that expression of the β-1,3-glucanase isoform blocked by antisense transformation is not necessary for ‘house-keeping’ functions of N. sylvestris nor defense against the fungal pathogen tested.
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resistance to disease in the hybrid Nicotiana glutinosa x Nicotiana debneyi is associated with high constitutive levels of β 1 3 glucanase chitinase peroxidase and polyphenoloxidase
Physiological and Molecular Plant Pathology, 1992Co-Authors: G Felix, Jean-pierre Métraux, Frederick MeinsAbstract:Abstract The tobacco hybrid Nicotiana glutinosa × Nicotiana debneyi is much more resistant than either parental species to tobacco mosaic virus, tobacco necrosis virus, Pseudomonas syringae pv. syringae, P. syringae pv. tabaci and Peronospora tabacina infections. While N. glutinosa is very susceptible to Cercospora Nicotianae, Chalara elegans and Phytophthora parasitica var. Nicotianae , the hybrid is as resistant as N. debneyi to these fungi. The resistance of the hybrid is linked to high levels of chitinase, β-1,3-glucanase, peroxidase (PO) and polyphenoloxidase (PPO). The parental species contain much lower levels of these enzymes unless they are locally infected with necrotizing viruses. In those cases, chitinase, β-1,3-glucanase and PO, but not PPO, increase in the whole plant to levels comparable with those found in the hybrid, and resistance to secondary infection develops (systemic acquired resistance). All the acidic isoenzymes of PO present in both parental species after infection are constitutively expressed in the hybrid. The activity of phenylalanine ammonia-lyase was similar in all plants. These results reinforce the hypothesis that hydrolases and PO are involved in resistance against various pathogens.
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high level expression of a tobacco chitinase gene in Nicotiana sylvestris susceptibility of transgenic plants to cercospora Nicotianae infection
Plant Molecular Biology, 1991Co-Authors: Jean-marc Neuhaus, Susan Flores, Patricia Ahlgoy, Ursula Hinz, Frederick MeinsAbstract:Endochitinases (E.C. 3.2.14, chitinase) are believed to be important in the biochemical defense of plants against chitin-containing fungal pathogens. We introduced a gene for class I (basic) tobacco chitinase regulated by Cauliflower Mosaic Virus 35S-RNA expression signals into Nicotiana sylvestris. The gene was expressed to give mature, enzymatically active chitinase targeted to the intracellular compartment of leaves. Most transformants accumulated extremely high levels of chitinase-up to 120-fold that of non-transformed plants in comparable tissues. Unexpectedly, some transformants exhibited chitinase levels lower than in non-transformed plants suggesting that the transgene inhibited expression of the homologous host gene. Progeny tests indicate this effect is not permanent. High levels of chitinase in transformants did not substantially increase resistance to the chitin-containing fungus Cercospora Nicotiana, which causes Frog Eye disease. Therefore class I chitinase does not appear to be the limiting factor in the defense reaction to this pathogen.
Alan G Smith - One of the best experts on this subject based on the ideXlab platform.
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polymorphism and structure of style specific arabinogalactan proteins as determinants of pollen tube growth in Nicotiana
BMC Evolutionary Biology, 2017Co-Authors: Andrzej K Noyszewski, Koichiro Tamura, Alan G SmithAbstract:Pollen tube growth and fertilization are key processes in angiosperm sexual reproduction. The transmitting tract (TT) of Nicotiana tabacum controls pollen tube growth in part by secreting pistil extensin-like protein III (PELPIII), transmitting-tract-specific (TTS) protein and 120 kDa glycoprotein (120 K) into the stylar extracellular matrix. The three arabinogalactan proteins (AGP) are referred to as stylar AGPs and are the focus of this research. The transmitting tract regulates pollen tube growth, promoting fertilization or rejecting pollen tubes. The N-terminal domain (NTD) of the stylar AGPs is proline rich and polymorphic among Nicotiana spp. The NTD was predicted to be mainly an intrinsically disordered region (IDR), making it a candidate for protein-protein interactions. The NTD is also the location for the majority of the predicted O-glycosylation sites that were variable among Nicotiana spp. The C-terminal domain (CTD) contains an Ole e 1-like domain, that was predicted to form beta-sheets that are similar in position and length among Nicotiana spp. and among stylar AGPs. The TTS protein had the greatest amino acid and predicted O-glycosylation conservation among Nicotiana spp. relative to the PELPIII and 120 K. The PELPIII, TTS and 120 K genes undergo negative selection, with dn/ds ratios of 0.59, 0.29 and 0.38 respectively. The dn/ds ratio for individual species ranged from 0.4 to 0.9 and from 0.1 to 0.8, for PELPIII and TTS genes, respectively. These data indicate that PELPIII and TTS genes are under different selective pressures. A newly discovered AGP gene, Nicotiana tabacum Proline Rich Protein (NtPRP), was found with a similar intron-exon configuration and protein structure resembling other stylar AGPs, particularly TTS. Further studies of the NtPRP gene are necessary to elucidate its biological role. Due to its high similarity to the TTS gene, NtPRP may be involved in pollen tube guidance and growth. In contrast to TTS, both PELPIII and 120 K genes are more diverse indicating a possible role in speciation or mating preference of Nicotiana spp. We hypothesize that the stylar AGPs and NtPRP share a common origin from a single gene that duplicated and diversified into four distinct genes involved in pollen-style interactions.
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Polymorphism and structure of style–specific arabinogalactan proteins as determinants of pollen tube growth in Nicotiana
BMC, 2017Co-Authors: Andrzej K Noyszewski, Koichiro Tamura, Yi-cheng Liu, Alan G SmithAbstract:Abstract Background Pollen tube growth and fertilization are key processes in angiosperm sexual reproduction. The transmitting tract (TT) of Nicotiana tabacum controls pollen tube growth in part by secreting pistil extensin-like protein III (PELPIII), transmitting-tract-specific (TTS) protein and 120 kDa glycoprotein (120 K) into the stylar extracellular matrix. The three arabinogalactan proteins (AGP) are referred to as stylar AGPs and are the focus of this research. The transmitting tract regulates pollen tube growth, promoting fertilization or rejecting pollen tubes. Results The N-terminal domain (NTD) of the stylar AGPs is proline rich and polymorphic among Nicotiana spp. The NTD was predicted to be mainly an intrinsically disordered region (IDR), making it a candidate for protein-protein interactions. The NTD is also the location for the majority of the predicted O-glycosylation sites that were variable among Nicotiana spp. The C-terminal domain (CTD) contains an Ole e 1-like domain, that was predicted to form beta-sheets that are similar in position and length among Nicotiana spp. and among stylar AGPs. The TTS protein had the greatest amino acid and predicted O-glycosylation conservation among Nicotiana spp. relative to the PELPIII and 120 K. The PELPIII, TTS and 120 K genes undergo negative selection, with dn/ds ratios of 0.59, 0.29 and 0.38 respectively. The dn/ds ratio for individual species ranged from 0.4 to 0.9 and from 0.1 to 0.8, for PELPIII and TTS genes, respectively. These data indicate that PELPIII and TTS genes are under different selective pressures. A newly discovered AGP gene, Nicotiana tabacum Proline Rich Protein (NtPRP), was found with a similar intron-exon configuration and protein structure resembling other stylar AGPs, particularly TTS. Conclusions Further studies of the NtPRP gene are necessary to elucidate its biological role. Due to its high similarity to the TTS gene, NtPRP may be involved in pollen tube guidance and growth. In contrast to TTS, both PELPIII and 120 K genes are more diverse indicating a possible role in speciation or mating preference of Nicotiana spp. We hypothesize that the stylar AGPs and NtPRP share a common origin from a single gene that duplicated and diversified into four distinct genes involved in pollen-style interactions
Pogány Miklós - One of the best experts on this subject based on the ideXlab platform.
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Egy molekuláris Növénykórtani Vizsgálatok Céljára Javasolható Növény−Gomba Kölcsönhatás
Környezetbarát Növényvédelemért Alapítvány, 2015Co-Authors: Tóth Evelin, Czuppon Bálint, Fodor József, Bozsó Zoltán, Pogány MiklósAbstract:Növénybiológiai kutatásaink egyik alapvetô modellszervezete a Nicotiana benthamiana. A faj molekuláris növénykórtani célokra történô felhasználását tovább erôsítené egy olyan növénypatogén gomba alkalmazása, mely a növényen specifi kus tüneteket okoz és laboratóriumi körülmények között könnyen és megbízhatóan használható. Munkánkban bemutatjuk, hogy a Cercospora Nicotianae hemibiotróf dohánykórokozó gomba hatékonyan fertôzi a N. benthamiana egyedeit. A laboratóriumi vizsgálatok céljára eddig nem elterjedt N. benthamiana−C. Nicotianae gazda−parazita kapcsolat a molekuláris növénykórtani és kórélettani kutatások kézenfekvô modellrendszere lehet
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EGY MOLEKULÁRIS NÖVÉNYKÓRTANI VIZSGÁLATOK CÉLJÁRA JAVASOLHATÓ NÖVÉNY-GOMBA KÖLCSÖNHATÁS
2014Co-Authors: Pogány Miklós, Tóth Evelin, Nagy, Veronika Anna, Köblös Gabriella, Fodor JózsefAbstract:A Nicotiana benthamiana széles körben használt vírusdiagnosztikai tesztnövény. Hatékony szervezete a vírus-indukált géncsendesítés (VIGS) jelenségének is, ezért jól alkalmazható növényi gének szerepének vizsgálatára. Ennek köszönhetően a molekuláris növénybiológia egyik fontos modellnövénye lett. Azonban csak kevés kórokozó gombáról közismert, hogy laboratóriumi körülmények között megbízhatóan fertőzi a N. benthamiana növényeket, ezek többsége polifág nekrotróf gombafaj (Botrytis cinerea, Colletotrichum spp.). Közleményünkben arról számolunk be, hogy a N. benthamiana erős fogékonyságot mutat a Cerkospórás levélfoltosság iránt, melyet a dohánykórokozó Cercospora Nicotianae tömlősgomba okoz. Eredményeink azt mutatják, hogy a N. benthamiana jóval fogékonyabb a Cerkospórás levélfoltosság betegség iránt, mint a kórokozó közismert gazdanövénye, a N. tabacum. Vizsgálataink célja, hogy a bemutatott növény−gomba kölcsönhatást jellemezzük, és modellkapcsolatként javasoljuk molekuláris növényvédelmi kutatások eszközeként. Megfigyeltük, hogy jelentősen csökken a C. Nicotianae által okozott szöveti nekrózis mértéke a leveleken, ha a N. benthamiana fitoén-deszaturáz mRNS szintjét VIGS módszerrel visszaszorítjuk. Ezeknek a géncsendesített növényeknek levelei több alapvető fotoszintetikus pigment hiánya miatt fehérek, amit a karotinoid bioszintézis gátlása okoz. Beszámolunk arról, hogy a gazda−parazita kapcsolatban fontos szerepet játszó különböző növényi hormonok (szalicilsav, etilén, jázmonsav) anyagcseréjének módosítása hogyan befolyásolja a beteg növényeken megjelenő tüneteket
Ramsey S. Lewis - One of the best experts on this subject based on the ideXlab platform.
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characterization of phytophthora Nicotianae resistance conferred by the introgressed Nicotiana rustica region wz in flue cured tobacco
Plant Disease, 2017Co-Authors: Kestrel Mccorkle, Ramsey S. Lewis, Katherine E Drakestowe, David H ShewAbstract:Black shank, caused by Phytophthora Nicotianae, is one of the most important diseases affecting tobacco worldwide and is primarily managed through use of host resistance. An additional source of resistance to P. Nicotianae, designated as Wz, has been introgressed into Nicotiana tabacum from N. rustica. The Wz gene region confers high levels of resistance to all races, but has not been characterized. Our study found Wz-mediated resistance is most highly expressed in the roots, with only a slight reduction in stem-lesion size in Wz genotypes compared with susceptible controls. No substantial relationships were observed between initial inoculum levels and disease development on Wz genotypes, which is generally consistent with qualitative or complete resistance. Isolates of P. Nicotianae adapted for five host generations on plants with the Wz gene caused higher disease severity than isolates adapted on Wz plants for only one host generation. Wz-adapted isolates did not exhibit increased aggressiveness on geno...
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growth chamber evaluation of a tobacco beinhart 1000 hicks mapping population for quantitative trait loci affecting resistance to multiple races of phytophthora Nicotianae
Crop Science, 2012Co-Authors: Vijay Vontimitta, Ramsey S. LewisAbstract:Multiple races of Phytophthora Nicotianae (van Breda de Haan) cause the black shank disease of tobacco (Nicotiana tabacum L.). Identifi cation of novel alleles affecting resistance and associated DNA markers might help increase the range and level of cultivar resistance. A doubled haploid mapping population generated from a highly resistant × susceptible cross (‘Beinhart 1000’ × ‘Hicks’) was evaluated for resistance after inoculation with either race 0 or race 1 in a growth chamber and also genotyped at 206 microsatellite marker loci. Multiple interval mapping identifi ed two major genomic regions affecting resistance to both races. A quantitative trait locus (QTL) on linkage group 8 explained 54.7 and 45.5% of the observed variation for end percent survival after race 0 and race 1 inoculation, respectively. A QTL on linkage group 4 explained a larger proportion (16.8%) of phenotypic variation for race 1 resistance as compared to race 0 resistance (1.8%). In combination with previously reported fi eld data, the study authenticates the role of these two regions on black shank resistance. Correlations of line performance under fi eld and growth chamber environments were good, and agreement was excellent at extreme levels of resistance or susceptibility. With appropriate isolate selection, growth chamber inoculations may provide a superior alternative to fi eld evaluations for mapping QTL affecting black shank resistance. Identifi ed QTL and associated markers may be useful for increasing levels of resistance to P. Nicotianae in tobacco cultivars.
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mapping of quantitative trait loci affecting resistance to phytophthora Nicotianae in tobacco Nicotiana tabacum l line beinhart 1000
Molecular Breeding, 2012Co-Authors: Vijay Vontimitta, Ramsey S. LewisAbstract:Black shank, caused by Phytophthora Nicotianae, is one of the most important diseases affecting tobacco (Nicotiana tabacum L.) production worldwide. While monogenic resistance to Race 0 of this pathogen has been transferred via interspecific introgression, quantitative resistance is currently needed to provide adequate resistance to all races. The objective of this research was to gain increased insight into the inheritance of resistance in the highly-resistant cigar tobacco line, Beinhart-1000, and to identify genomic regions contributing to this resistance. A doubled haploid population was generated from a cross between Beinhart-1000 and the susceptible cultivar, Hicks. The population was evaluated for field resistance in three environments and genotyped with 206 polymorphic microsatellite markers. No doubled haploid line exhibited as high a level of resistance as Beinhart-1000. Heritability was high and multiple interval mapping suggested that at least six quantitative trait loci (QTL) may contribute to the high level of resistance in this line. The two largest QTL explained 25.4 and 20.4% of the observed phenotypic variation for end percent survival. A model including all six significant QTL explained 64.3% of the phenotypic variation and 73.1% of the genetic variation. The two major identified QTL and their associated markers may be of use for employing Beinhart-1000 as a source of black shank resistance in tobacco breeding. The major QTL on linkage group four was found to cosegregate with Abl, a gene involved in accumulation of the trichome exudate cis-abienol. The question of pleiotropy versus linkage needs to be investigated with respect to partial resistance against P. Nicotianae.
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variability for resistance to phytophthora Nicotianae within a collection of Nicotiana rustica accessions
Plant Disease, 2011Co-Authors: Jessica M Nifong, J S Nicholson, H D Shew, Ramsey S. LewisAbstract:Abstract Black shank, caused by Phytophthora Nicotianae, is one of the most important diseases affecting tobacco (Nicotiana tabacum) production worldwide. Many current tobacco cultivars possess immunity to race 0 of this pathogen conferred by introgressed dominant genetic factors. Novel alleles conditioning resistance to alternative races are desired. The objective of this research was to evaluate variability for black shank resistance within a collection of N. rustica germplasm using both soilborne disease nurseries and controlled race-specific (race 0 and race 1) inoculations. Nearly all of the 86 accessions studied exhibited very high resistance to race 0, and many displayed levels of race 1 resistance greater than that exhibited by the resistant flue-cured tobacco check, ‘K 346’. Materials found to be highly resistant to race 0 and race 1 in growth-chamber experiments also had the best survivability in field disease nurseries. N. rustica accessions TR 6, TR 12, TR 16, TR 21, TR 20, TR 48, TR 54, TR 57...
Fodor József - One of the best experts on this subject based on the ideXlab platform.
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Egy molekuláris Növénykórtani Vizsgálatok Céljára Javasolható Növény−Gomba Kölcsönhatás
Környezetbarát Növényvédelemért Alapítvány, 2015Co-Authors: Tóth Evelin, Czuppon Bálint, Fodor József, Bozsó Zoltán, Pogány MiklósAbstract:Növénybiológiai kutatásaink egyik alapvetô modellszervezete a Nicotiana benthamiana. A faj molekuláris növénykórtani célokra történô felhasználását tovább erôsítené egy olyan növénypatogén gomba alkalmazása, mely a növényen specifi kus tüneteket okoz és laboratóriumi körülmények között könnyen és megbízhatóan használható. Munkánkban bemutatjuk, hogy a Cercospora Nicotianae hemibiotróf dohánykórokozó gomba hatékonyan fertôzi a N. benthamiana egyedeit. A laboratóriumi vizsgálatok céljára eddig nem elterjedt N. benthamiana−C. Nicotianae gazda−parazita kapcsolat a molekuláris növénykórtani és kórélettani kutatások kézenfekvô modellrendszere lehet
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EGY MOLEKULÁRIS NÖVÉNYKÓRTANI VIZSGÁLATOK CÉLJÁRA JAVASOLHATÓ NÖVÉNY-GOMBA KÖLCSÖNHATÁS
2014Co-Authors: Pogány Miklós, Tóth Evelin, Nagy, Veronika Anna, Köblös Gabriella, Fodor JózsefAbstract:A Nicotiana benthamiana széles körben használt vírusdiagnosztikai tesztnövény. Hatékony szervezete a vírus-indukált géncsendesítés (VIGS) jelenségének is, ezért jól alkalmazható növényi gének szerepének vizsgálatára. Ennek köszönhetően a molekuláris növénybiológia egyik fontos modellnövénye lett. Azonban csak kevés kórokozó gombáról közismert, hogy laboratóriumi körülmények között megbízhatóan fertőzi a N. benthamiana növényeket, ezek többsége polifág nekrotróf gombafaj (Botrytis cinerea, Colletotrichum spp.). Közleményünkben arról számolunk be, hogy a N. benthamiana erős fogékonyságot mutat a Cerkospórás levélfoltosság iránt, melyet a dohánykórokozó Cercospora Nicotianae tömlősgomba okoz. Eredményeink azt mutatják, hogy a N. benthamiana jóval fogékonyabb a Cerkospórás levélfoltosság betegség iránt, mint a kórokozó közismert gazdanövénye, a N. tabacum. Vizsgálataink célja, hogy a bemutatott növény−gomba kölcsönhatást jellemezzük, és modellkapcsolatként javasoljuk molekuláris növényvédelmi kutatások eszközeként. Megfigyeltük, hogy jelentősen csökken a C. Nicotianae által okozott szöveti nekrózis mértéke a leveleken, ha a N. benthamiana fitoén-deszaturáz mRNS szintjét VIGS módszerrel visszaszorítjuk. Ezeknek a géncsendesített növényeknek levelei több alapvető fotoszintetikus pigment hiánya miatt fehérek, amit a karotinoid bioszintézis gátlása okoz. Beszámolunk arról, hogy a gazda−parazita kapcsolatban fontos szerepet játszó különböző növényi hormonok (szalicilsav, etilén, jázmonsav) anyagcseréjének módosítása hogyan befolyásolja a beteg növényeken megjelenő tüneteket
