| [amides of amino acids and peptides as antifungal agents]. | the synthesis of pyrazolyl-amides of aminoacids and peptides is described. the chemicals were tested for antifungal activity against wheat powdery mildew (erysiphe graminis dc.), cucumber powdery mildew (erysiphe cichoracearum dc.), wheat brown rust (puccinia recondita rob. ex desm. f. sp. tritici erikss et henn.), celery leaf spot (septoria apii briosi ed cav. chest.) and collar rot (rhizoctonia solani kuhn). some of these compounds showed antifungal activity. | 1982 | 7128803 |
| [derivatives of 4-nitroso-aminopyrazole as antifungal agents]. | the synthesis of 4-nitroso-5-amminopyrazoles and of 4-nitroso-5-pyrazolylurethans and -ureas is described. the chemicals were tested for antifungal activity against erysiphe graminis, erysiphe cichoracearum, puccinia recondita, septoria apii and rhizoctonia solani. a number of the described compounds showed some antifungal activity. | 1981 | 7319023 |
| genetic characterization of five powdery mildew disease resistance loci in arabidopsis thaliana. | this paper reports on six arabidopsis accessions that show resistance to a wild isolate of the powdery mildew pathogen, erysiphe cichoracearum. resistance at 7 days post-inoculation in these accessions was characterized by limited fungal growth and sporadic development of chlorotic or necrotic lesions at inoculation sites. three accessions, wa-1, kas-1 and si-0, were highly resistant, while the other accessions permitted some fungal growth and conidiation. papilla formation was a frequent host r ... | 1996 | 8919911 |
| an arabidopsis mutant with enhanced resistance to powdery mildew. | we have identified an arabidopsis mutant that displays enhanced disease resistance to the fungus erysiphe cichoracearum, causal agent of powdery mildew. the edr1 mutant does not constitutively express the pathogenesis-related genes pr-1, bgl2, or pr-5 and thus differs from previously described disease-resistant mutants of arabidopsis. e. cichoracearum conidia (asexual spores) germinated normally and formed extensive hyphae on edr1 plants, indicating that the initial stages of infection were not ... | 1998 | 9634583 |
| pathogen-induced elicitin production in transgenic tobacco generates a hypersensitive response and nonspecific disease resistance. | the rapid and effective activation of disease resistance responses is essential for plant defense against pathogen attack. these responses are initiated when pathogen-derived molecules (elicitors) are recognized by the host. we have developed a strategy for creating novel disease resistance traits whereby transgenic plants respond to infection by a virulent pathogen with the production of an elicitor. to this end, we generated transgenic tobacco plants harboring a fusion between the pathogen-ind ... | 1999 | 9927640 |
| comparison of erysiphe cichoracearum and e. cruciferarum and a survey of 360 arabidopsis thaliana accessions for resistance to these two powdery mildew pathogens. | in previous work, uea1 and ucsc1, two geographically distinct, powdery mildew isolates, were recognized for their ability to infect arabidopsis thaliana. we have clarified the identity of these isolates by determining their host ranges, reexamining their morphology, and comparing their dna sequences for the 5.8s ribosomal rna and two flanking internal transcribed spacer sequences. these experiments confirm that uea1 is a member of erysiphe cruciferarum and that ucsc1 belongs to e. cichoracearum. ... | 1999 | 10624012 |
| isolation and characterization of powdery mildew-resistant arabidopsis mutants. | a compatible interaction between a plant and a pathogen is the result of a complex interplay between many factors of both plant and pathogen origin. our objective was to identify host factors involved in this interaction. these factors may include susceptibility factors required for pathogen growth, factors manipulated by the pathogen to inactivate or avoid host defenses, or negative regulators of defense responses. to this end, we identified 20 recessive arabidopsis mutants that do not support ... | 2000 | 10677553 |
| three unique mutants of arabidopsis identify eds loci required for limiting growth of a biotrophic fungal pathogen. | to identify components of the defense response that limit growth of a biotrophic fungal pathogen, we isolated arabidopsis mutants with enhanced disease susceptibility to erysiphe orontii. our initial characterization focused on three mutants, eds14, eds15, and eds16. none of these is considerably more susceptible to a virulent strain of the bacterial pathogen pseudomonas syringae pv. maculicola (psm). all three mutants develop a hypersensitive response when infiltrated with psm expressing the av ... | 2000 | 11069695 |
| negative regulation of defense responses in plants by a conserved mapkk kinase. | the enhanced disease resistance 1 (edr1) mutation of arabidopsis confers resistance to powdery mildew disease caused by the fungus erysiphe cichoracearum. resistance mediated by the edr1 mutation is correlated with induction of several defense responses, including host cell death. double mutant analysis revealed that all edr1-associated phenotypes are suppressed by mutations that block salicylic acid (sa) perception (nim1) or reduce sa production (pad4 and eds1). the nahg transgene, which lowers ... | 2001 | 11114160 |
| isolation and characterization of broad-spectrum disease-resistant arabidopsis mutants. | to identify arabidopsis mutants that constitutively express systemic acquired resistance (sar), we constructed reporter lines expressing the firefly luciferase gene under the control of the sar-inducible pr-1 promoter (pr-1/luc). after ems mutagenesis of a well-characterized transgenic line, we screened 250,000 m(2) plants for constitutive expression of the reporter gene in vivo. from a mutant collection containing several hundred putative mutants, we concentrated on 16 mutants lacking spontaneo ... | 2002 | 11973319 |
| [influence of phytohormones on development of conidial inoculum of causative agents of the phlox and barley powdery mildew]. | we studied the role of phytohormones: zeatin, kinetin, and abscisic acid, in the regulation of development of the conidial inoculum of erysiphe cichoracearum dc. f. phlogis jacz. and e. graminis dc. f. hordei marchal. when the pathogen conidia were in direct contact with phytohormones, the intensity of their germination significantly increased. in the presence of cytokinins, the amount of normal appressoria decreased and that of abnormal growth tubes increased. on the phlox leaves treated with c ... | 2002 | 12068440 |
| pmr6, a pectate lyase-like gene required for powdery mildew susceptibility in arabidopsis. | the plant genes required for the growth and reproduction of plant pathogens are largely unknown. in an effort to identify these genes, we isolated arabidopsis mutants that do not support the normal growth of the powdery mildew pathogen erysiphe cichoracearum. here, we report on the cloning and characterization of one of these genes, pmr6. pmr6 encodes a pectate lyase-like protein with a novel c-terminal domain. consistent with its predicted gene function, mutations in pmr6 alter the composition ... | 2002 | 12215508 |
| constitutive activation of jasmonate signaling in an arabidopsis mutant correlates with enhanced resistance to erysiphe cichoracearum, pseudomonas syringae, and myzus persicae. | in arabidopsis spp., the jasmonate (ja) response pathway generally is required for defenses against necrotrophic pathogens and chewing insects, while the salicylic acid (sa) response pathway is generally required for specific, resistance (r) gene-mediated defenses against both biotrophic and necrotrophic pathogens. for example, sa-dependent defenses are required for resistance to the biotrophic fungal pathogen erysiphe cichoracearum ucsc1 and the bacterial pathogen pseudomonas syringae pv. macul ... | 2002 | 12437300 |
| overexpression of a kinase-deficient form of the edr1 gene enhances powdery mildew resistance and ethylene-induced senescence in arabidopsis. | the edr1 gene of arabidopsis has previously been reported to encode a raf-like mitogen-activated protein kinase kinase (mapkk) kinase, and to function as a negative regulator of disease resistance. a phylogenetic analysis of plant and animal protein kinases revealed, however, that plant raf-like kinases are more closely related to animal mixed lineage kinases (mlks) than raf-like kinases, and are deeply divergent from both classes of animal kinases, making inferences of substrate specificity que ... | 2002 | 12492839 |
| [influence of exogenous salicylic acid on the level of phytohormones in tissues of phlox paniculata and phlox setacea leaves with special reference to resistance against the powdery mildew causative agent erysiphe cichoracearum d.c. f. phlogis jacz]. | we studied the effects of exogenous salicylic acid on the level of endogenous cytokinins and abscisic and salicylic acids in the tissues of leaves of phloxes contrasting in resistance against the powdery mildew causative agent: susceptible phlox paniculata l. and resistant ph. setacea l. studies were carried out under the conditions of biotic stress. the initial level of salicylic and abscisic acids and cytokinins is the highest in the resistant phlox species. after treatment with salicylic spec ... | 2002 | 12561329 |
| actin-related defense mechanism to reject penetration attempt by a non-pathogen is maintained in tobacco by-2 cells. | the actin cytoskeleton is a key player in defense responses during early stages of infection by fungal pathogens. to investigate molecular mechanisms of actin-related defense responses, a cultured tobacco ( nicotiana tabacum l.) by-2 cell system was devised. when conidia were directly deposited on by-2 cells, neither a pathogen, erysiphe cichoracearum, nor a non-pathogen, erysiphe pisi, was able to form appressoria or haustoria on by-2 cells. on the other hand, conidia of the powdery mildews for ... | 2003 | 12728320 |
| the monosaccharide transporter gene, atstp4, and the cell-wall invertase, atbetafruct1, are induced in arabidopsis during infection with the fungal biotroph erysiphe cichoracearum. | powdery mildew fungi are biotrophic pathogens that form a complex interface, the haustorium, between the host plant and the parasite. the pathogen acts as an additional sink, competing with host sinks, resulting in considerable modification of photoassimilate production and partitioning within the host tissue. here, we examine the factors that may contribute to these changes. we show for the first time in one biotrophic interaction (arabidopsis/erysiphe cichoracearum) all of the following respon ... | 2003 | 12805612 |
| targeted activation tagging of the arabidopsis nbs-lrr gene, adr1, conveys resistance to virulent pathogens. | a transgenic arabidopsis line containing a chimeric pr-1::luciferase (luc) reporter gene was subjected to mutagenesis with activation tags. screening of lines via high-throughput luc imaging identified a number of dominant arabidopsis mutants that exhibited enhanced pr-1 gene expression. here, we report the characterization of one of these mutants, designated activated disease resistance (adr) 1. this line showed constitutive expression of a number of key defense marker genes and accumulated sal ... | 2003 | 12906111 |
| the pseudomonas syringae type iii effector avrrpt2 functions downstream or independently of sa to promote virulence on arabidopsis thaliana. | avrrpt2, a pseudomonas syringae type iii effector protein, functions from inside plant cells to promote the virulence of p. syringae pv. tomato strain dc3000 (pstdc3000) on arabidopsis thaliana plants lacking a functional copy of the corresponding rps2 resistance gene. in this study, we extended our understanding of avrrpt2 virulence activity by exploring the hypothesis that avrrpt2 promotes pstdc3000 virulence by suppressing plant defenses. when delivered by pstdc3000, avrrpt2 suppresses pathog ... | 2004 | 14756766 |
| the pen1 syntaxin defines a novel cellular compartment upon fungal attack and is required for the timely assembly of papillae. | attack by the host powdery mildew erysiphe cichoracearum usually results in successful penetration and rapid proliferation of the fungus on arabidopsis. by contrast, the nonhost barley powdery mildew blumeria graminis f. sp. hordei (bgh) typically fails to penetrate arabidopsis epidermal cells. in both instances the plant secretes cell wall appositions or papillae beneath the penetration peg of the fungus. genetic screens for mutations that result in increased penetration of bgh on arabidopsis h ... | 2004 | 15342780 |
| host and non-host pathogens elicit different jasmonate/ethylene responses in arabidopsis. | arabidopsis does not support the growth and asexual reproduction of the barley pathogen, blumeria graminis f. sp. hordei bgh). a majority of germlings fail to penetrate the epidermal cell wall and papillae. to gain additional insight into this interaction, we determined whether the salicylic acid (sa) or jasmonate (ja)/ethylene (et) defence pathways played a role in blocking barley powdery mildew infections. only the eds1 mutant and nahg transgenics supported a modest increase in penetration suc ... | 2004 | 15546348 |
| mutations in pmr5 result in powdery mildew resistance and altered cell wall composition. | powdery mildews and other obligate biotrophic pathogens are highly adapted to their hosts and often show limited host ranges. one facet of such host specialization is likely to be penetration of the host cell wall, a major barrier to infection. a mutation in the pmr5 gene rendered arabidopsis resistant to the powdery mildew species erysiphe cichoracearum and erysiphe orontii, but not to the unrelated pathogens pseudomonas syringae or peronospora parasitica. pmr5 belongs to a large family of plan ... | 2004 | 15584961 |
| an arabidopsis npr1-like gene, npr4, is required for disease resistance. | the arabidopsis genome contains six npr1-related genes. given the pivotal role played by npr1 in controlling salicylic acid (sa)-mediated gene expression and disease resistance, functional characterization of other family members appears to be justified. reverse genetics was used to analyze the role of one npr1-like gene, which we called npr4. the npr4 protein shares 36% identity with npr1 and interacts with the same spectrum of tga transcription factors in yeast two-hybrid assays. plants with t ... | 2005 | 15634206 |
| new, rare or remarkable microfungi in the italian alps (carnic alps)--part ii--other microfungi. | in addition to the collection of ascomycotina in the carnic alps (see new, rare or remarkable microfungi in the italian alps (carnic alps) part i ) we were able to treasure about 300 species of parasitic and saprophytic microfungi. among them basidiomycetes, ascomycetes and deuteromycets like bostrichonema polygoni (unger) schrot. on polygonum viviparum l., chrysomyxa rhododendri de by on picea abies (l.) karsten, coleosporium tussilaginis (pers.) berk. i=c. cacaliae otth.] on adenostyles glabra ... | 2004 | 15756827 |
| loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen erysiphe cichoracearum. | chitin is a major component of fungal walls and insect exoskeletons. plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. using the ath1 affymetrix microarrays consisting of about 23,000 genes, we examined the response of arabidopsis (arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. the expression patterns elicited by the chito-octamer an ... | 2005 | 15923325 |
| regulation of plant defense responses in arabidopsis by edr2, a ph and start domain-containing protein. | we have identified an arabidopsis mutant that displays enhanced disease resistance (edr2) to the biotrophic powdery mildew pathogen erysiphe cichoracearum. inhibition of fungal growth on edr2 mutant leaves occurred at a late stage of the infection process and coincided with formation of necrotic lesions approximately 5 days after inoculation. double-mutant analysis revealed that edr2-mediated resistance is suppressed by mutations that inhibit salicylic acid (sa)-induced defense signaling, includ ... | 2005 | 16212604 |
| arabidopsis thaliana subcellular responses to compatible erysiphe cichoracearum infections. | subcellular events of erysiphe cichoracearum infections of epidermal cells were visualized in living tissues of arabidopsis plants carrying various green fluorescent protein (gfp)-tagged organelles via laser scanning confocal microscopy. early in the infection sequence, cytoplasm and organelles moved towards penetration sites and accumulated near penetration pegs. peroxisomes appeared to accumulate preferentially relative to the cytoplasm at penetration sites. another early event, which preceded ... | 2005 | 16236160 |
| isolation, cloning and expression analysis of ecpma1, a putative plasma membrane h+ -atpase transporter gene from the biotrophic pathogenic fungus erysiphe cichoracearum. | little is known at the molecular level about the transporters involved in nutrient transfer in the plant/powdery mildew interaction. a pcr-based approach was used to identify and isolate a partial-length cdna coding for an isoform of the plasma membrane h+ -atpase (ecpma1) in the biotrophic pathogenic fungus erysiphe cichoracearum. southern analysis suggests that ecpma1 exists as a single-copy gene. sequence analysis indicated a high similarity of ecpma1 to other fungal h+ -atpases. expression o ... | 2006 | 16431274 |
| arabidopsis pen3/pdr8, an atp binding cassette transporter, contributes to nonhost resistance to inappropriate pathogens that enter by direct penetration. | arabidopsis thaliana is a host to the powdery mildew erysiphe cichoracearum and nonhost to blumeria graminis f. sp hordei, the powdery mildew pathogenic on barley (hordeum vulgare). screening for arabidopsis mutants deficient in resistance to barley powdery mildew identified penetration3 (pen3). pen3 plants permitted both increased invasion into epidermal cells and initiation of hyphae by b. g. hordei, suggesting that pen3 contributes to defenses at the cell wall and intracellularly. pen3 mutant ... | 2006 | 16473969 |
| wrky70 modulates the selection of signaling pathways in plant defense. | cross-talk between signal transduction pathways is a central feature of the tightly regulated plant defense signaling network. the potential synergism or antagonism between defense pathways is determined by recognition of the type of pathogen or pathogen-derived elicitor. our studies have identified wrky70 as a node of convergence for integrating salicylic acid (sa)- and jasmonic acid (ja)-mediated signaling events during plant response to bacterial pathogens. here, we challenged transgenic plan ... | 2006 | 16623907 |
| transgenic expression of gallerimycin, a novel antifungal insect defensin from the greater wax moth galleria mellonella, confers resistance to pathogenic fungi in tobacco. | a cdna encoding gallerimycin, a novel antifungal peptide from the greater wax moth galleria mellonella, was isolated from a cdna library of genes expressed during innate immune response in the caterpillars. upon ectopic expression of gallerimycin in tobacco, using agrobacterium tumefaciens as a vector, gallerimycin conferred resistance to the fungal pathogens erysiphe cichoracearum and sclerotinia minor. quantification of gallerimycin mrna in transgenic tobacco by real-time pcr confirmed transge ... | 2006 | 16740126 |
| a mutation in the gtp hydrolysis site of arabidopsis dynamin-related protein 1e confers enhanced cell death in response to powdery mildew infection. | we screened for mutants of arabidopsis thaliana that displayed enhanced disease resistance to the powdery mildew pathogen erysiphe cichoracearum and identified the edr3 mutant, which formed large gray lesions upon infection with e. cichoracearum and supported very little sporulation. the edr3-mediated disease resistance and cell death phenotypes were dependent on salicylic acid signaling, but independent of ethylene and jasmonic acid signaling. in addition, edr3 plants displayed enhanced suscept ... | 2006 | 16824181 |
| transcriptional changes in powdery mildew infected wheat and arabidopsis leaves undergoing syringolin-triggered hypersensitive cell death at infection sites. | blumeria graminis f.sp. tritici, the causal agent of powdery mildew in wheat, is an obligate biotrophic fungus that exclusively invades epidermal cells. as previously shown, spraying of a solution of syringolin a, a circular peptide derivative secreted by the phytopathogenic bacterium pseudomonas syringae pv. syringae, triggers hypersensitive cell death at infection sites in powdery mildew infected wheat. thus, the fungus is essentially eradicated. here we show that syringolin a also triggers hy ... | 2006 | 16941219 |
| the evaluation of trifloxystrobin in protection of calendula officinalis (pot marigold) against erysiphe cichoracearum dc. | the aim of the two-years field's examinations was the evaluation of the fungicide zato 50 wg (biologically active substances bas--trifloxystrobin 50%) in protection of calendula officinalis (pot marigold) against erysiphe cichoracearum. mentioned fungicide was applied at three concentrations: 0.1, 0.15 and 0.2%. as the standard fungicide amistar 250 sc (biologically active substances bas - azoxystrobin 250 g/dm3) was used. in every year of research work the four protective treatments were carrie ... | 2006 | 17390856 |
| mutations in lacs2, a long-chain acyl-coenzyme a synthetase, enhance susceptibility to avirulent pseudomonas syringae but confer resistance to botrytis cinerea in arabidopsis. | we identified an arabidopsis (arabidopsis thaliana) mutant, sma4 (symptoms to multiple avr genotypes4), that displays severe disease symptoms when inoculated with avirulent strains of pseudomonas syringae pv tomato, although bacterial growth is only moderately enhanced compared to wild-type plants. the sma4 mutant showed a normal susceptible phenotype to the biotrophic fungal pathogen erysiphe cichoracearum. significantly, the sma4 mutant was highly resistant to a necrotrophic fungal pathogen, b ... | 2007 | 17434992 |
| inoculum production and long-term conservation methods for cucurbits and tomato powdery mildews. | the behaviour of cucurbit powdery mildews (podosphaera xanthii and golovinomyces cichoracearum) and tomato powdery mildew (oidium neolycopersici) infesting detached cotyledons of lagenaria leucantha cv. 'minibottle' was studied in order to develop an easy culture method for pure inoculum production. high spore production was found with a combination of mannitol (0.1 m), sucrose (0.02 m) and agar (8 gl(-1)) in the cotyledon survival medium. sporulation on cotyledons and viability of conidia were ... | 2007 | 17604145 |
| genome-wide expression profiling arabidopsis at the stage of golovinomyces cichoracearum haustorium formation. | compatibility between plants and obligate biotrophic fungi requires fungal mechanisms for efficiently obtaining nutrients and counteracting plant defenses under conditions that are expected to induce changes in the host transcriptome. a key step in the proliferation of biotrophic fungi is haustorium differentiation. here we analyzed global gene expression patterns in arabidopsis thaliana leaves during the formation of haustoria by golovinomyces cichoracearum. at this time, the endogenous levels ... | 2008 | 18218973 |
| 3-acetonyl-3-hydroxyoxindole: a new inducer of systemic acquired resistance in plants. | systemic acquired resistance (sar) is an inducible defence mechanism which plays a central role in protecting plants from microbial pathogen attack. guided by bioassays, a new chemical inducer of sar was isolated from the extracts of strobilanthes cusia and identified to be 3-acetonyl-3-hydroxyoxindole (aho), a derivative of isatin. tobacco plants treated with aho exhibited enhanced resistance to tobacco mosaic virus (tmv) and to the fungal pathogen erysiphe cichoracearum (powdery mildew), accom ... | 2008 | 18266823 |
| powdery mildew resistance conferred by loss of the enhanced disease resistance1 protein kinase is suppressed by a missense mutation in keep on going, a regulator of abscisic acid signaling. | loss-of-function mutations in the arabidopsis (arabidopsis thaliana) enhanced disease resistance1 (edr1) gene confer enhanced resistance to infection by powdery mildew (golovinomyces cichoracearum). edr1 encodes a protein kinase, but its substrates and the pathways regulated by edr1 are unknown. to identify components of the edr1 signal transduction pathway(s), we conducted a forward genetic screen for mutations that suppressed edr1-mediated disease resistance. genetic mapping and cloning of one ... | 2008 | 18815384 |
| relationship between loci conferring downy mildew and powdery mildew resistance in melon assessed by quantitative trait loci mapping. | abstract partial resistance to downy mildew (pseudoperonospora cubensis) and complete resistance to powdery mildew (podosphaera xanthii races 1, 2, 3, and 5 and golovinomyces cichoracearum race 1) were studied using a recombinant inbred line population between 'pi 124112' (resistant to both diseases) and 'védrantais' (susceptible line). a genetic map of melon was constructed to tag these resistances with dna markers. natural and artificial inoculations of pseudoperonospora cubensis were performe ... | 2005 | 18943322 |
| inorganic salts for suppressing powdery mildew in cucurbits--a worldwide survey. | the present review provides an update of recent progress in the use of inorganic salts to manage powdery mildew (sphaerotheca fuliginea and erysiphe cichoracearum) in cucurbits (cucurbitaceae). a literature survey identified 16 salts, mainly bicarbonates (e.g. khco3), phosphates (e.g. k2hpo4) and silicates (e.g. na2sio3), as having potential to suppress powdery mildew in cucurbits. the percentage suppression compared with untreated controls was calculated from the best treatment of each of 20 pe ... | 2008 | 19226741 |
| survey of microfungi in the kleinwalsertal (austrian alps). | during an excursion to the alps near the german/austrian border (kleinwalsertal) in august 2007, we were able to collect more than 40 species of microfungi as parasites or saprophytes on different parts of wild plants. some of them have been observed only rarely until now. most of the species collected belong to the classes ascomycotina, basidiomycotina, and deuteromycotina. for example: -leptosphaeria jaceae holm on centaurea jacea l.; -mycosphaerella equiseticola bond.-mont. on equisetum telma ... | 2008 | 19226751 |
| plant-pathogen interactions and elevated co2: morphological changes in favour of pathogens. | crop losses caused by pests and weeds have been estimated at 42% worldwide, with plant pathogens responsible for almost $10 billion worth of damage in the usa in 1994 alone. elevated carbon dioxide [eco(2)] and associated climate change have the potential to accelerate plant pathogen evolution, which may, in turn, affect virulence. plant-pathogen interactions under increasing co(2) concentrations have the potential to disrupt both agricultural and natural systems severely, yet the lack of experi ... | 2009 | 19470658 |
| allelopathic potential and chemical constituents of volatiles from ageratum conyzoides under stress. | the allelopathic potential of ageratum conyzoides was investigated under different environmental stress conditions, including nutrient deficiency. physical damage, 2.4-d treatment, competition with bidens pilosa, infection with erysiphe cichoracearum, and feeding by aphiids gossypii. the inhibitory effects of a. conyzoides volatiles on peanut (arachis hypogaea), redroot amaranth (amaranthus retroflexus), cucumber (cucumis sativus), and ryegrass (lolium multiforum) increased when plants were grow ... | 2002 | 12184395 |
| the arabidopsis resurrection1 gene regulates a novel antagonistic interaction in plant defense to biotrophs and necrotrophs. | we report a role for the arabidopsis (arabidopsis thaliana) resurrection1 (rst1) gene in plant defense. the rst1 mutant exhibits enhanced susceptibility to the biotrophic fungal pathogen erysiphe cichoracearum but enhanced resistance to the necrotrophic fungal pathogens botrytis cinerea and alternaria brassicicola. rst1 encodes a novel protein that localizes to the plasma membrane and is predicted to contain 11 transmembrane domains. disease responses in rst1 correlate with higher levels of jasm ... | 2009 | 19625635 |
| biodiversity and new records of microfungi in the ruhrarea (north rhine westfalia), germany. | during our investigations of the microflora in nrw (duisburg, düsseldorf and essen incl. the greenhouse of the botanical garden) in 2007 and 2008, we were able to collect and identify about 55 species on trees, bushes and ornamental plants as parasites and saprophytes. some of these species are new for germany or have been only rarely found until now. most of the species belong the ascomycotina, basidiomycotina and deuteromycotina for example arthrocladiella mougeotii (lév.) vassilkov. on lycium ... | 2009 | 20222564 |
| synergistic activation of defense responses in arabidopsis by simultaneous loss of the gsl5 callose synthase and the edr1 protein kinase. | loss-of-function mutations in the edr1 gene of arabidopsis confer enhanced resistance to golovinomyces cichoracearum (powdery mildew). disease resistance mediated by the edr1 mutation is dependent on an intact salicylic acid (sa) signaling pathway, but edr1 mutant plants do not constitutively express the sa-inducible gene pr-1 and are not dwarfed. to identify other components of the edr1 signaling network, we screened for mutations that enhanced the edr1 mutant phenotype. here, we describe an en ... | 2010 | 20367466 |
| expression and functional analysis of two genes encoding transcription factors, vpwrky1 and vpwrky2, isolated from chinese wild vitis pseudoreticulata. | in this study, two wrky genes were isolated from erysiphe necator-resistant chinese wild vitis pseudoreticulata w. t. wang 'baihe-35-1', and designated as vpwrky1 (genbank accession no. gq884198) and vpwrky2 (genbank accession no. gu565706). nuclear localization of the two proteins was demonstrated in onion epidermal cells, while trans-activation function was confirmed in the leaves of 'baihe-35-1'. expression of vpwrky1 and vpwrky2 was induced rapidly by salicylic acid treatment in 'baihe-35-1' ... | 2010 | 20811906 |
| identification and utilization of a sow thistle powdery mildew as a poorly adapted pathogen to dissect post-invasion non-host resistance mechanisms in arabidopsis. | to better dissect non-host resistance against haustorium-forming powdery mildew pathogens, a sow thistle powdery mildew isolate designated golovinomyces cichoracearum umsg1 that has largely overcome penetration resistance but is invariably stopped by post-invasion non-host resistance of arabidopsis thaliana was identified. the post-invasion non-host resistance is mainly manifested as the formation of a callosic encasement of the haustorial complex (ehc) and hypersensitive response (hr), which ap ... | 2010 | 21193574 |
| atl9, a ring zinc finger protein with e3 ubiquitin ligase activity implicated in chitin- and nadph oxidase-mediated defense responses. | pathogen associated molecular patterns (pamps) are signals detected by plants that activate basal defenses. one of these pamps is chitin, a carbohydrate present in the cell walls of fungi and in insect exoskeletons. previous work has shown that chitin treatment of arabidopsis thaliana induced defense-related genes in the absence of a pathogen and that the response was independent of the salicylic acid (sa), jasmonic acid (ja) and ethylene (et) signaling pathways. one of these genes is atl9 ( = a ... | 2010 | 21203445 |
| atg2, an autophagy-related protein, negatively affects powdery mildew resistance and mildew-induced cell death in arabidopsis. | the molecular interactions between arabidopsis and the pathogenic powdery mildew golovinomyces cichoracearum were studied by characterizing a disease resistant arabidopsis mutant atg2-2. the atg2-2 mutant showed enhanced resistance to powdery mildew and dramatic mildew-induced cell death as well as early senescence phenotypes in the absence of pathogens. defense-related genes were constitutively activated in atg2-2. in atg2-2 mutants, spontaneous cell death, early senescence and disease resistan ... | 2011 | 21645148 |
| negative regulation of defence signalling pathways by the edr1 protein kinase. | the enhanced disease resistance 1 (edr1) mutant of arabidopsis confers enhanced resistance to bacterial and fungal pathogens. to better understand how edr1-mediated resistance occurs, we performed transcriptome analyses on wild-type and edr1 plants inoculated with the fungal pathogen golovinomyces cichoracearum (powdery mildew). the expression of many known and putative defence-associated genes was more rapidly induced, and to higher levels, in edr1 plants relative to the wild-type. many of the ... | 2011 | 21726375 |
| design, synthesis, biological activities, and 3d-qsar of new n,n'-diacylhydrazines containing 2-(2,4-dichlorophenoxy)propane moiety. | a series of new n,n'-diacylhydrazine derivatives were synthesized efficiently under microwave irradiation. their structures were characterized by (1) h nmr, ms, and elemental analysis. various biological activities of these compounds were tested. most of them exhibited higher herbicidal activities against dicotyledonous weeds than monocotyledonous weeds. in addition, favorable in vivo fungicidal activities were also found of these compounds against cladosporium cucumerinum, corynespora cassiicol ... | 2011 | 21816005 |
| HPR1, a component of the THO/TREX complex, plays an important role in disease resistance and senescence in Arabidopsis. | ENHANCED DISEASE RESISTANCE 1 (EDR1) is a negative regulator of powdery mildew resistance, cell death and ethylene-induced senescence. To identify components involved in EDR1 signaling, we performed a forward genetic screen for edr1 suppressors. In this screen, we identified the hpr1-4 mutation, which partially suppresses edr1-mediated resistance to the powdery mildew pathogen Golovinomyces cichoracearum and mildew-induced cell death. However, the hpr1-4 mutation enhanced the ethylene-induced se ... | 2011 | 22035198 |
| the autophagy gene, atg18a, plays a negative role in powdery mildew resistance and mildew-induced cell death in arabidopsis. | autophagy is a conserved intracellular recycling system that traffics cellular organelles and cytosolic proteins within lysosomes for reuse or breakdown in eukaryotes. increased evidence indicates that autophagy is involved in programmed cell death and disease resistance in plants. we recently showed that atg2, atg5, atg7 and atg10 displayed early senescence and cell death in later growth stage under nutrient-rich conditions in arabidopsis thaliana. these mutants also exhibited powdery mildew re ... | 2011 | 21847024 |
| Novel Benzo-1, 2, 3-thiadiazole-7-carboxylate derivatives as plant activators and the development of their agricultural applications. | Plant activators are a novel kind of agrochemicals that could induce resistance in many plants against a broad spectrum of diseases. To date, only few plant activators have been commercialized. In order to develop novel plant activators, a series of benzo-1, 2, 3-thiadiazole-7-carboxylate derivatives were synthesized and the structures were characterized by 1H NMR, IR, elemental analyses and HRMS or MS. Their potential systemic acquired resistance as plant activators was evaluated as well. Most ... | 2011 | 22142181 |
| vprfp1, a novel c4c4-type ring finger protein gene from chinese wild vitis pseudoreticulata, functions as a transcriptional activator in defence response of grapevine. | ring finger proteins comprise a large family and play important roles in regulation of growth and development, hormone signalling, and responses to biotic and abiotic stresses in plants. in this study, the identification and functional characterization of a c4c4-type ring finger protein gene from the chinese wild grapevine vitis pseudoreticulata (designated vprfp1) are reported. vprfp1 was initially identified as an expressed sequence tag (est) from a cdna library constructed from leaves of v. p ... | 2011 | 21862480 |
| role of pathogen-induced volatiles in the nicotiana tabacum-golovinomyces cichoracearum interaction. | plant injuries activate signal transduction cascades mediated by the plant hormones, which lead to enhanced expression of defence related genes and/or to changes in the emission of volatile organic compounds that can act as semiochemicals. in this research we demostrated that infection with the biotrophic pathogen golovinomyces cichoracearum (dc.) v.p. heluta (ex erysiphe cichoracearum dc.), the causal agent of powdery mildew, led in the susceptible host nicotiana tabacum l. cv havana 425 to an ... | 2011 | 22305063 |