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similarity of cellulose xerogels of japanese pears in ultrastructure to chitin xerogels chemically prepared. 1978689269
organization of ribosomal rna genes in alternaria alternata japanese pear pathotype, a host-selective ak-toxin-producing fungus.dna encoding ribosomal rna (rrna) of alternaria alternata japanese pear pathotype has been cloned in lambda replacement vector, lambda fix. restriction endonuclease mapping and southern hybridization with the 18s and 28s rrnas of saccharomyces cerevisiae revealed the a. alternata rdna to be tandemly repeating 8.15-kilobase pair unit. the restriction fragments of the unit were then subcloned in the plasmid vector bluescribe m13- and partially sequenced. the determined sequences were compared with ...19892697467
pollen allergy due to artificial pollination of japanese pear: an occupational hazard. 20063374106
nystatin controls botryodiplodia rot of pears (pyrus pyrifolia burm f.). 20003835181
[occupational apple and pear pollinosis among apple- and pear-growing farmers and cross-allergenicity between japanese apple pollen and japanese pear pollen]. 19854038085
[an epidemiological examination of pollinosis in an apple (malus pumila miller var. domestica schneider) and pear (pyrus serotina var. culta) growing district]. 19854091663
[2 cases of japanese pear (pyrus serotina) pollinosis]. 19846525030
a comparative study of the word sugar and of its equivalents in hindustani as traceable to chinese.etymology enables words to deliver past facts and can become an independent source of knowledge. here the word sugar is traced to the chinese term sha-che, literally "sand-sugar plant," signifying a sand-like product from the sugar plant, which is sugar. sha-che underwent the following phonetic changes: sha-che = sha-ke = shar-ker = sharkera, which became the sanskrit word for sugar, with the variant sha-kera. its popular vernacular form became shak-ker. this entered arabic as al-shakker, changi ...19816764089
[pollenosis due to artificial pollination of japanese pears (author's transl)]. 19817265550
molecular aspects of self-incompatibility in flowering plants.it is seven years since the first reports of cdnas encoding pistil glycoproteins that segregated with particular s-alleles. during this time, the s-glycoproteins of the solanaceae have been identified as rnases. this enzymatic activity relies on the presence of histidine residues at the putative active site of the rnase, and these are conserved in all s-glycoproteins so far characterized. the proteins also contain "hypervariable" regions that may have some role in allelic specificity. it is part ...19938122904
identification and characterization of stylar glycoproteins associated with self-incompatibility genes of japanese pear, pyrus serotina rehd.japanese pear (pyrus serotina rehd.) exhibits gametophytic self-incompatibility. following our previous findings that basic ribonucleases in the styles of japanese pear are associated with self-incompatibility genes (s-rnases), stylar proteins with high pi values were analyzed by two-dimensional gel electrophoresis further to characterize s-rnases. a group of basic proteins of about 30 kda associated with self-incompatibility genes were identified. these proteins contained sugar chains which rea ...19938232200
self-incompatibility (s) alleles of the rosaceae encode members of a distinct class of the t2/s ribonuclease superfamily.stylar ribonucleases (rnases) are associated with gametophytic self-incompatibility in two plant families, the solanaceae and the rosaceae. the self-incompatibility-associated rnases (s-rnases) of both the solanaceae and the rosaceae were recently reported to belong to the t2 rnase gene family, based on the presence of two well-conserved sequence motifs. here, the cloning and characterization of s-rnase genes from two species of rosaceae, apple (malus x domestica) and japanese pear (pyrus seroti ...19968676858
identification and partial amino acid sequences of seven s-rnases associated with self-incompatibility of japanese pear, pyrus pyrifolia nakai.s-allele-specific proteins (s-proteins) were separated and identified by two-dimensional (2d) gel electrophoresis from the style extract of 14 cultivars of japanese pear, pyrus pyrifolia nakai, which exhibits gametophytic self-incompatibility. these s-proteins were 30-32 kda basic proteins with putative pis of 9.6-10.1 and were distinct from the other proteins, which were common for all cultivars examined. each s-protein was assigned to a given s-genotype based on electrophoretic mobility and th ...19968889818
molecular cloning and nucleotide sequences of cdnas encoding s-allele specific stylar rnases in a self-incompatible cultivar and its self-compatible mutant of japanese pear, pyrus pyrifolia nakai.the genes encoding three rnases were cloned from the style of a self-incompatible cultivar, nijisseiki (s2s4), and its self-compatible mutant, osa-nijisseiki (s2s4sm, sm means stylar part mutant), of japanese pear. for nijisseiki, cdnas coding for two s-rnase (s2-rnase and s4-rnase) and an rnase unrelated to self-incompatibility (non-s-rnase) were cloned from the stylar cdna library. the cdnas coding for s2-rnase, s4-rnase, and non-s-rnase include 678-, 684-, and 681-bp open reading frames, resp ...19968889819
location of cysteine and cystine residues in s-ribonucleases associated with gametophytic self-incompatibility.s-ribonucleases (s-rnases) that cosegregate with s-alleles in the styles of solanaceous and rosaceous plants are associated with gametophytic self-incompatibility (gsi). the amino acid sequences of many s-rnases have been derived from cdna sequences, but the state of half-cystines has not been clarified. we report the locations of the two free cysteine residues and four disulfide bridges of tobacco s6-rnase and of the four disulfide bridge of japanese pear s4-rnase. the protein was first s-pyrid ...19969022690
circular dna plasmid in the phytopathogenic fungus alternaria alternata: its temperature-dependent curing and association with pathogenicity.we found the presence of plasmid dna in strain t88-56 of the japanese pear pathotype of alternaria alternata, which causes black spot of certain cultivars of japanese pear by producing host-specific ak-toxin. the plasmid, designated paat56, was identified to be an approximately 5.4-kilobase (kb) circular molecule by electron microscopic observation and restriction endonuclease mapping. southern blot analysis showed that paat56 dna had no homology with either nuclear or mitochondrial dna. culture ...19979136005
identification of stylar rnases associated with gametophytic self-incompatibility in almond (prunus dulcis).stylar proteins of 13 almond (prunus dulcis) cultivars with known s-genotypes were surveyed by ief and 2d-page combined with immunoblot and n-terminal amino acid sequence analyses to identify s-rnases associated with gametophytic self-incompatibility (si) in this plant species. rnase activities corresponding to sa and sb, two of the four s-alleles tested, were identified by ief and rnase activity staining. the sa-rnase band reacted with the anti-s4-serum prepared from japanese pear (pyrus seroti ...19979150603
structural analysis of the plasmid paat56 of the filamentous fungus alternaria alternata.the circular dna plasmid, designated paat56, has been isolated from strain t88-56 of the japanese pear pathotype of alternaria alternata. we determined the complete nucleotide sequence (5354 bp) of paat56 and mapped its possible open reading frames (orfs). three long orfs, orf1 (1290 bp), orf2 (1653 bp) and orf3 (690 bp), and four smaller orfs, orf4 to orf7 (> or = 300 bp), were predicted from the sequence. the potential peptides derived from the orfs other than orf2 show no homology to other kn ...19979426006
characterization of the flanking regions of the s-rnase genes of japanese pear (pyrus serotina) and apple (malus x domestica).genomic sequences of the self-incompatibility genes, the s-rnase genes, from two rosaceous species, japanese pear and apple, were characterized. genomic southern blot and sequencing of a 4.5-kb genomic clone showed that the s4-rnase gene of japanese pear is surrounded by repetitive sequences as in the case of the s-rnase genes of solanaceous species. the flanking regions of the s2- and sf-rnase genes of apple were also cloned and sequenced. the 5' flanking regions of the three alleles bore no si ...19989573352
style-specific and developmentally regulated accumulation of a glycosylated thaumatin/pr5-like protein in japanese pear (pyrus serotina rehd.).the stylar proteins of japanese pear (pyrus serotina rehd.) were analyzed by two-dimensional gel electrophoresis, and a 32-kda protein with an isoelectric point of 4.8 was found to be a major component in the style. the 32-kda protein was a soluble glycoprotein which reacted with concanavalin a. the 32-kda protein specifically accumulated in the style in a developmentally regulated manner, but was not detected in the other floral organs and leaves. an oligonucleotide representing the n-terminal ...19989684355
primary structural features of rosaceous s-rnases associated with gametophytic self-incompatibility.we isolated cdna clones encoding five s-rnases (s1-, s3-, s5-, s6-, s7-rnases) from pistils of pyrus pyrifolia (japanese pear), a member of the rosaceae. their amino acid sequences were aligned with those of other rosaceous s-rnases sequenced so far. a total of 76 conserved amino acid residues were stretched throughout the sequence, but were absent from the 51-66 region which was designated the hypervariable (hv) region. the phylogenetic tree of rosaceous s-rnases showed that s-rnase polymorphis ...19989700066
targeted disruption of a melanin biosynthesis gene affects conidial development and uv tolerance in the japanese pear pathotype of alternaria alternata.structural analysis of the brm2 gene involved in melanin biosynthesis of the japanese pear pathotype of alternaria alternata suggested that this gene encodes 1,3,8-trihydroxynaphthalene reductase. targeted disruption of the brm2 gene did not affect pathogenicity, vegetative growth, or the number of conidia produced. targeted disruption, however, did reduce conidial size and septal number, suggesting that melanin is associated with conidial development. the conidia of brm2 mutant transformants we ...19999885194
nucleotide sequence of seed- and pollen-transmitted double-stranded rna, which encodes a putative rna-dependent rna polymerase, detected from japanese pear.the nucleotide sequence of the largest double-stranded (ds) rna (named dsrna1) of three species of seed- and pollen-transmitted dsrna species detected from japanese pear was analyzed, and one strand was found to contain a single long open reading frame (orf) of 1434 nucleotides that encoded a putative polypeptide containing 477 amino acid residues with a molecular mass of 54.9 kda. this polypeptide contained amino acid sequence motifs conserved in putative rna-dependent rna polymerases of rna vi ...19989972231
identification of 1-aminocyclopropane-1-carboxylic acid synthase genes controlling the ethylene level of ripening fruit in japanese pear (pyrus pyrifolia nakai).the shelf life of japanese pear fruit is determined by its level of ethylene production. relatively high levels of ethylene reduce storage potential and fruit quality. we have identified rflp markers tightly linked to the locus that determines the rate of ethylene evolution in ripening fruit of the japanese pear. the study was carried out using sequences of two types of 1-aminocyclopropane-1-carboxylic acid (acc) synthase genes (ppacs1 and pppacs2) and a acc oxidase gene (ppaox1) as probes on 35 ...199910071208
erwinia pyrifoliae sp. nov., a novel pathogen that affects asian pear trees (pyrus pyrifolia nakai)a novel pathogen from asian pears (pyrus pyrifolia nakai) was analysed by sequencing the 16s rdna and the adjacent intergenic region, and the data were compared to related enterobacteriaceae. the 16s rdna of the asian pear pathogen was almost identical with the sequence of erwinia amylovora, in contrast to the 16s-23s rrna intergenic transcribed spacer region of both species. a dendrogram was deduced from determined sequences of the spacer regions including those of several related species such ...199910319516
immunological and molecular comparison of polyphenol oxidase in rosaceae fruit trees.an antibody raised against apple polyphenol oxidase (ppo) cross-reacted with ppos from japanese pear (pyrus pyrifolia), pear (pyrus communis), peach (prunus persica), chinese quince (pseudocydonia sinensis) and japanese loquat (eriobotrya japonica). core fragments (681 bp) of the corresponding ppo genes were amplified and characterized. the deduced protein sequences showed identities of 85.3 to 97.5%. chlorogenic acid oxidase activity of these ppos showed higher activities when assayed at ph 4 t ...199910385997
seasonal allergic conjunctivitis induced by japanese pear pollen.to evaluate the ocular findings in patients with japanese pear (pyrus pyrifolia nakai) pollinosis.201310413261
insertional mutagenesis and cloning of the genes required for biosynthesis of the host-specific ak-toxin in the japanese pear pathotype of alternaria alternata.the japanese pear pathotype of alternaria alternata causes black spot of japanese pear by producing a host-specific toxin known as ak-toxin. restriction enzyme-mediated integration (remi) mutagenesis was used to tag genes required for toxin biosynthesis. protoplasts of a wild-type strain were treated with a linearized plasmid along with the restriction enzyme used to linearize the plasmid. of 984 remi transformants recovered, three produced no detectable ak-toxin and lost pathogenicity on pear l ...199910432635
presence of asparagine-linked n-acetylglucosamine and chitobiose in pyrus pyrifolia s-rnases associated with gametophytic self-incompatibility.s-rnases encoded by the s-locus of rosaceous and solanaceous plants discriminate between the s-alleles of pollen in gametophytic self-incompatibility reactions, but it is not clear how. we report the structures of n-glycans attached to each of the n-glycosylation sites of seven s-rnases in pyrus pyrifolia of the rosaceae. the structures were identified by chromatographic analysis of pyridylaminated sugar chains prepared from s4-rnase and by liquid chromatography/electrospray ionization-mass spec ...199910469125
purification and characterization of two sucrose synthase isoforms from japanese pear fruit.two isoforms (ss i and ss ii) of sucrose synthase (ss; ec 2.54.1.13) were purified from japanese pear fruit and their properties were compared. ss i mainly appeared in young fruit and ss ii mainly in mature fruit. ss i and ss ii were purified to the specific activity of 3.37 and 4.26 (units (mg protein)(-1)), respectively. the mw of native and subunit proteins of ss i and ss ii were almost the same and both sss seemed to be a tetramer composed of an 83 kda polypeptide. however, the ionic charges ...200010845453
real, an ltr retrotransposon from the plant pathogenic fungus alternaria alternata.a retrotransposon was isolated and characterized from strain 15a of the japanese pear pathotype of alternaria alternata, which causes black spot disease in certain cultivars of japanese pear by producing a host-specific toxin known as ak-toxin. the element, which we have named real (retrotransposon of alternaria alternata), is 6046 bp in size and contains direct long terminal repeats (ltrs) of 218 bp. target-site duplication of 5 bp was found. real contains two long overlapping orfs. the first o ...200010852484
migration of organophosphorus insecticides cyanophos and prothiofos residues from impregnated paper bags to japanese apple-pears (pyrus pyrifolia nakai cv. nijisseiki).bags impregnated with the organophosphorus pesticides prothiofos and cyanophos in three levels were used to cover japanese apple-pears to protect them from insects. the amounts of prothiofos residue in the bags collected 4 months after application ranged from 0 to 34% of the amounts (81, 148, and 333 microg) found in the bags prior to a bagging. the amounts of cyanophos residue in bags collected 4 months after application ranged from 11 to 29% of the amounts (335, 2860, and 3740 microg) present ...200010888575
isolation of cdna clones corresponding to genes expressed during fruit ripening in japanese pear (pyrus pyrifolia nakai): involvement of the ethylene signal transduction pathway in their expression.thirty cdna clones of genes corresponding to mrnas up-regulated during fruit ripening of japanese pear (pyrus pyrifolia nakai cv. kikusui) were obtained by differential screening of a ripe fruit cdna library. all of these cdnas were sequenced and gathered into 11 non-redundant groups after database searches. these clones represented genes associated with stress responses, protein catabolism or pathogenesis. the accumulation of transcripts of 3 out of 11 genes was inhibited by 1-methylcyclopropen ...200010948244
purification and characterization of a nad+-dependent sorbitol dehydrogenase from japanese pear fruit.nad+-dependent sorbitol dehydrogenase nad-sdh, ec 1.1.1.14) from japanese pear fruit was purified to apparent homogeneity (single band by sds-page with silver staining), and had a specific activity of 916.7 nkatal/mg protein. the molecular of the native enzyme was calculated to be 160 kda by gel filtration, whereas sds-page gave a subunit size of 40 kda, indicating that the native enzyme is a homotetramer. the protein immunologically reacted with an antibody raised in rabbit against the fusion p ...200010963448
structural and functional complexity of the genomic region controlling ak-toxin biosynthesis and pathogenicity in the japanese pear pathotype of alternaria alternata.the japanese pear pathotype of alternaria alternata produces host-specific ak-toxin and causes black spot of japanese pear. previously, a cosmid clone, pcakt-1, was isolated that contains two genes, akt1 and akt2, within a 5.0-kb region required for ak-toxin biosynthesis. the wild-type strain has multiple, nonfunctional copies of these genes. in the present study, two additional genes, aktr-1 and akt3-1, downstream of akt2 were identified. transformation of the wild type with aktr-1- and akt3-1- ...200010975654
purification and crystallization of japanese pear s-rnase associated with gametophytic self-incompatibility.s-rnase is a 25 kda pistil-specific protein associated with gametophytic self-incompatibility. the s-rnase is secreted into the transmitting tissue of the pistil and is responsible for the discrimination of pollen s-alleles. crystals of japanese pear s(3)-rnase were obtained by the hanging-drop vapour-diffusion method. preliminary x-ray data showed that the crystals diffract to a 1.5 a resolution and belong to the space group p2(1), with unit-cell parameters a = 45.4, b = 52.4, c = 47.4 a, alpha ...200111134948
binding affinity of the methyl ester of ak-toxin i to membrane fractions from japanese pear leaves.the binding site of ak-toxin, a host-specific toxin against japanese pear, was searched for in the membrane fractions of the pear leaves, using 3h-labeled ak-toxin i methyl ester. binding activity, which was displaceable by the unlabeled ligand, was observed for microsomal fraction from a toxin-susceptible cultivar, nijisseiki. however, the binding was also observed for those from toxin-resistant cultivars, kosui and hosui. detection of the specific binding failed for the plasma membrane fractio ...200011193431
thermodynamic analysis of diffusion of non-electrolytes across plant cuticles in the presence and absence of the plasticiser tributyl phosphate.solute mobility in cuticular membranes (cms) of 14 plant species (citrus aurantiumn l., citrus grandis l., hedera helix l., ilex aquifolium l., ilex paraguariensis st.-hil., malus domestica borkh. cv. golden delicious, populus alba l., prunus laurocerasus l., pyrus communis l. cv. bartlett, conference and gellerts butterbirne, pyrus pyrifolia (burm. f.) nakai, schefflera actinophylla (endl.) harms and strophanthus gratus baill.) was measured over the temperature range 25-55 degrees c. the five o ...200011219574
molecular cloning of beta-galactosidase from japanese pear (pyrus pyrifolia) and its gene expression with fruit ripening.we have cloned a cdna fragment encoding a beta-galactosidase from japanese pear (pyrus pyrifolia) fruit (jp-gal). it contained an untranslated sequence of 182 nucleotides at the 5' end, a presumptive coding sequence of 2,193 nucleotides and an untranslated sequence of 268 nucleotides including a polyadenylation signal and a poly (a) tail at the 3' end. it encoded a protein with a calculated molecular weight of 80.9 kda which consists of 731 amino acids. both the nucleotide and the deduced amino ...200111382815
lupeol esters from the twig bark of japanese pear (pyrus serotina rehd.) cv. shinko.five new lupeol esters, lup-20(29)-ene-3beta-yl eicosanoate, docosanoate, tetracosanoate, hexacosanoate and octacosanoate, were isolated as a mixture from the twig bark of japanese pear (pyrus serotina rehd.) cv. shinko, together with lupeol and epifriedelinol. their structures were determined by spectral analyses including 2d-nmr experiments.200111440139
crystal structure at 1.5-a resolution of pyrus pyrifolia pistil ribonuclease responsible for gametophytic self-incompatibility.the crystal structure of the pyrus pyrifolia pistil ribonuclease (s(3)-rnase) responsible for gametophytic self-incompatibility was determined at 1.5-a resolution. it consists of eight helices and seven beta-strands, and its folding topology is typical of rnase t(2) family enzymes. based on a structural comparison of s(3)-rnase with rnase rh, a fungal rnase t(2) family enzyme, the active site residues of s(3)-rnase assigned were his(33) and his(88) as catalysts and glu(84) and lys(87) as stabili ...200111577107
seasonal occurrence of specialist and generalist insect predators of spider mites and their response to volatiles from spider-mite-infested plants in japanese pear orchards.in two adjacent japanese pear orchards (orchards i and 2), we studied the seasonal occurrence of the kanzawa spider mite. tetranychus kanzawai, and its predators. also the response of these predators to the volatiles from kidney bean plants infested with t kanzawai was investigated using trap boxes in orchard 1. the mite density in orchard 1 was unimodal. with one peak at the end of august. in this orchard, population development of the specialist insect predators, scolothrips takahashii, oligot ...200111603732
molecular comparison of pathogenic bacteria from pear trees in japan and the fire blight pathogen erwinia amylovora.several strains of the genus erwinia, which were isolated in japan from pear trees with necrotic symptoms that resembled fire blight, and tentatively identified as erwinia amylovora, were reinvestigated for their relationship to the fire blight pathogen. these isolates produced ooze on slices of immature pears and were mucoid on mm2cu agar plates, but did not synthesize levan and did not give the expected pcr signals with several primer pairs specific for erwinia amylovora. the isolates tested p ...200111700346
synthesis of theaflavin from epicatechin and epigallocatechin by plant homogenates and role of epicatechin quinone in the synthesis and degradation of theaflavin.oxidation products of (-)-epicatechin and (-)-epigallocatechin by treatment with homogenates of 62 plants belonging to 49 families were compared. forty-six plants were capable of synthesizing theaflavin, a black tea pigment, regardless of whether they contained catechins. loquat, japanese pear, and blueberry had activities higher than that of fresh tea leaves after 5 h of treatment; furthermore, these plants oxidized theaflavin to theanaphthoquinone. an additional new metabolite, dehydrotheasine ...200211902970
changes in the phosphorylation state of sucrose synthase during development of japanese pear fruit.changes in the protein level and phosphorylation state of sucrose synthase (ss) were studied throughout the development of japanese pear fruit. the level of ss protein was high at the young stage, dropped with fruit enlargement and increased again with fruit maturation. antibody against phospho-ser reacted with ss from young fruit, but did not react with ss that had been dephosphorylated by alkaline phosphatase (ap). the activities of ss isozymes were separated by ion-exchange chromatography. it ...200211982930
a conditionally dispensable chromosome controls host-specific pathogenicity in the fungal plant pathogen alternaria alternata.the filamentous fungus alternaria alternata contains seven pathogenic variants (pathotypes), which produce host-specific toxins and cause diseases on different plants. previously, the gene cluster involved in host-specific ak-toxin biosynthesis of the japanese pear pathotype was isolated, and four genes, named akt genes, were identified. the akt homologs were also found in the strawberry and tangerine pathotypes, which produce af-toxin and act-toxin, respectively. this result is consistent with ...200212019223
determination of s-genotypes of pear (pyrus pyrifolia) cultivars by s-rnase sequencing and pcr-rflp analyses.the pear (pyrus pyrifolia) has gametophytic self-incompatibility (gsi). to elucidate the s-genotypes of korean-bred pear cultivars, whose parents are heterozygotes, the pcr amplification using s-rnase primers that are specific for each s-genotype was carried out in 15 korean-bred pear cultivars and 5 japanese-bred pear cultivars. the difference of the fragment length was shown in the following order: s6 (355 bp) < s7 (360 bp) < s1 (375 bp) < s4 (376 bp) < s3 and s5 (384 bp) < s8 (442 bp) < s9 (1 ...200212132585
a pistil-specific thaumatin/pr5-like protein gene of japanese pear (pyrus serotina): sequence and promoter activity of the 5' region in transgenic tobacco.the genomic clone encoding the pistil-specific thaumatin/pr5-like protein (pstl1) was isolated from japanese pear (pyrus serotina). sequence analysis showed that the genomic clone contained the 5'-flanking sequence of 2.4 kb, the 3'-flanking sequence of 648 bp and the coding region interrupted by a intron of 351 bp. a sequence motif conserved in some pistil self-incompatibility gene promoters of solanaceous and brassicaceous species was located in the 5'-flanking region of the pstl1 gene. the 2. ...200212369614
characterization of erwinia amylovora strains using random amplified polymorphic dna fragments (rapds).the genetic diversity among 16 strains of erwinia amylovora, chosen to represent different host plant origins and geographical regions, was investigated by rapd analysis. one strain of erwinia herbicola and one of agrobacterium vitis were used as outgroups. ninety-eight different rapd fragments were produced by polymerase chain reaction amplification with six different 10-mer primers. rapd banding profiles were found that enabled the erw. amylovora strains to be distinguished from one another. c ...199712455904
genetics of biosynthesis and structure of the capsular exopolysaccharide from the asian pear pathogen erwinia pyrifoliae.erwinia pyrifoliae is a novel bacterial pathogen, which causes asian pear blight and is related to erwinia amylovora, the causative agent of fire blight. e. pyrifoliae produces exopolysaccharide (eps) related to amylovoran in its sugar composition and sugar linkages. this was shown by degradation of the eps with a viral depolymerase, and by methylation analysis and esi/ms. the structure of the repeating units was confirmed by (1)h-nmr spectra. the eps of e. pyrifoliae carried side chains, which ...200212480905
comparative analysis of chloroplast dna in pyrus species: physical map and gene localization.a physical map of chloroplast dna (cpdna) of pear [pyrus ussuriensis var. hondoensis (nakai et kikuchi) rehder] was constructed using five restriction enzymes, sali, xhoi, bamhi, saci and psti. this information will make it possible to investigate the phylogenetic relationships between pyrus species. pear cpdna was found to be a circular molecule with a total size of about 156 kb in which two inverted repeats of 24.8 kb divide the molecule into small (17 kb) and large (90 kb) single-copy regions ...200312582856
genetic linkage maps constructed by using an interspecific cross between japanese and european pears.genetic linkage maps of the european pear ( pyrus communis l.) cultivar 'bartlett' and the japanese pear ( pyrus pyrifolia nakai) cultivar 'housui' were constructed based on aflps, ssrs from pear, apple and prunus, isozymes and phenotypic traits by using their f(1) progenies. the map of the female parent bartlett consisted of 226 loci including 175 aflps, 49 ssrs, one isozyme and one s locus on 18 linkage groups over a total length of 949 cm, while that for 'housui' contained 154 loci including ...200212582866
protein glycation inhibitory and antioxidative activities of some plant extracts in vitro.the protein glycation inhibitory activity of aqueous ethanolic extracts from 25 plant tissues was evaluated in vitro using the model system of bovine serum albumin and fructose. the most bioactive plant tissue was allium cepa (skin), followed by illicium religiosum (bark and wood), fagopyrum esculentum (hull), origanum officinalis (leaf), rosmarinus officinalis (leaf), pyrus pyrifolia (bark),acanthopanax senticosus (bark), eugenia caryophllata (leaf), and erigeron annuus (whole). the extracts wi ...200312617589
[performance study of analytical method for ethoxyquin in fruit].a performance study of an analytical method of ethoxyquin (et) in apples and pears was conducted. in the proposed method, the sample was homogenized with thiourea and et was extracted with acetone instead of hexane used in the official analytical method for et, in order to improve the extraction efficiency. furthermore, dibutyl hydroxytoluene was added in the test solution to prevent the decomposition of et. for evaluation of the method. et spiked into apples and pears at the level of 0.2 microg ...200212635340
purification and characterization of two soluble acid invertase isozymes from japanese pear fruit.two isozymes (aiv i and aiv ii) of soluble acid invertase (ec 3.2.1.26) were purified from japanese pear fruit through procedures including (nh(4))(2)so(4) precipitating, deae-sephacel column chromatography, concanavalin a (cona)-sepharose affinity chromatography, hydroxyapatite column chromatography and mono q hr 5/5 column chromatography. the specific activities of purified aiv i and aiv ii were 2670 and 2340 (nkat/mg protein), respectively. aiv i was a monomeric enzyme of 80 kda, while aiv ii ...200312711132
rapid identification of 1-aminocyclopropane-1-carboxylate (acc) synthase genotypes in cultivars of japanese pear (pyrus pyrifolia nakai) using caps markers.in japanese pear (pyrus pyrifolia nakai), fruit storage potential is closely related to the amount of ethylene produced. we have developed a rapid and accurate method for analyzing genes involved in high ethylene production during fruit ripening in japanese pear. this involves cleaved-amplified polymorphic sequences (caps) of two 1-aminocyclopropane-1-carboxylate (acc) synthase genes (ppacs1 and ppacs2). two caps markers (a for ppacs1 and b for ppacs2), associated with the amount of ethylene pro ...200312748778
[determination of captafol, cyhexatin, 1-naphthylacetic acid and quintozene in apple, japanese pear and melon by simultaneous extraction].a simple and rapid method is described for the determination of the non-registered pesticides, captafol, quintozene (pcnb), cyhexatin and 1-naphthylacetic acid (naa), in fruits. these pesticides were extracted with acidified acetone, then captafol and pcnb were purified with a florisil mini column and analyzed by gc-ecd. cyhexatin was ethylated with ethylmagnesium bromide, and the ethyl derivative was analyzed by gc-fpd (sn filter). naa was purified with liquid-liquid extraction and determined b ...200312846161
molecular markers derived from rapd, scar, and the conserved 18s rdna sequences for classification and identification in pyrus pyrifolia and p. communis.we generated rapd, scar, and conserved 18s rdna markers for classifying and identifying cultivars of pyrus pyrifolia (japanese pear) and p. communis (european pear). pcr amplification with selected specific primers-lch327up and lch327down-was performed using dna extracted from 25 p. pyrifolia and p. communis cultivars. the 1,380-bp fragment was amplified from p. communis cvs. beurre giffard, cascade, conference, clapp's favorite, packhams triumph, and winter nelis. rapd has only a dominant singl ...200414749847
the effect of different atmospheric ozone partial pressures on photosynthesis and growth of nine fruit and nut tree species.nursery stock of peach (prunus persica l. batsch, cv. o'henry), nectarine (p. persica l. batsch, cv. fantasia), plum (p. salicina lindel., cv. casselman), apricot (p. armeniaca l., cv. tilton), almond (p. dulcis mill., cv. nonpareil), prune (p. domestica l., cv. improved french), cherry (p. avium l., cv. bing), oriental pear (pyrus pyrifolia rehd., cv. 20th century), and apple (malus pumula mill., cv. granny smith) were planted in open-top chambers on april 1, 1988 at the university of californi ...199114972900
molecular differentiation of erwinia amylovora strains from north america and of two asian pear pathogens by analyses of pfge patterns and hrpn genes.in order to determine a possible genomic divergence of erwinia amylovora'fruit tree' and raspberry strains from north america, several isolates were differentiated by pulsed-field gel electrophoresis (pfge) analysis, the size of short dna sequence repeats (ssrs) and the nucleotide and deduced amino acid sequences of their hrpn genes. by pfge analysis european strains are highly related, whereas strains from north america were diverse and were further distinguished by the ssr numbers from plasmid ...200415049921
dissection of the host range of the fungal plant pathogen alternaria alternata by modification of secondary metabolism.the filamentous fungus alternaria alternata contains seven pathogenic variants (pathotypes), which produce different host-specific toxins and cause diseases on different plants. the strawberry pathotype produces host-specific af-toxin and causes alternaria black spot of strawberry. this pathotype is also pathogenic to japanese pear cultivars susceptible to the japanese pear pathotype that produces ak-toxin. the strawberry pathotype produces two related molecular species, af-toxins i and ii: toxi ...200415066029
asian pear pectin administration during presensitization inhibits allergic response to ovalbumin in balb/c mice.a type of respiratory disorder resembling some aspects of human allergic asthma can be induced in mice using ovalbumin. the factors that influence the etiology of asthma are poorly understood even though cytokines are known to play a pivotal role. the purpose of this study was to test the hypothesis whether an administration of asian pear pectin during presensitization could suppress allergic response to ovalbumin in balb/c mice.200415253858
european, chinese and japanese pear fruits exhibit differential softening characteristics during ripening.softening characteristics were investigated in three types of pear fruit, namely, european pear 'la france', chinese pear 'yali', and japanese pear 'nijisseiki'. 'la france' fruit softened dramatically and developed a melting texture during ripening, while 'yali' fruit with and without propylene treatment showed no change in flesh firmness and texture during ripening. non-treated 'nijisseiki' did not show a detectable decrease in flesh firmness, whereas continuous propylene treatment caused a gr ...200415333646
nucleotide sequences of a korean isolate of apple stem grooving virus associated with black necrotic leaf spot disease on pear (pyrus pyrifolia).pear black necrotic leaf spot (pbnls) is a disease of pears caused by capillovirus-like particles, which can be observed under the electron microscope. the disease was analyzed by western blot analysis with antisera raised against apple stem grooving virus (asgv) coat protein. cdnas covering the entire genome were synthesized by rt-pcr and race using rna isolated from chenopodium quinoa infected with sap extracted from pear leaves carrying black necrotic spot disease. the complete genome sequenc ...200415528995
partitioning of (13)c-photosynthate from spur leaves during fruit growth of three japanese pear (pyrus pyrifolia) cultivars differing in maturation date.in fruit crops, fruit size at harvest is an important aspect of quality. with japanese pears (pyrus pyrifolia), later maturing cultivars usually have larger fruits than earlier maturing cultivars. it is considered that the supply of photosynthate during fruit development is a critical determinant of size. to assess the interaction of assimilate supply and early/late maturity of cultivars and its effect on final fruit size, the pattern of carbon assimilate partitioning from spur leaves (source) t ...200515655106
multiresidue determination of pesticides in agricultural products by gas chromatography/mass spectrometry with large volume injection.a method is described for the rapid determination of pesticide residues in agricultural products. pesticides were extracted from samples with acetonitrile. to remove pigments and fatty acids, an aliquot of the extract was cleaned up by a minicolumn that was packed both with graphitized carbon black and primary secondary amine. analysis was performed by gas chromatography/ mass spectrometry with programmable temperature vaporizer-based large volume injection using a liner packed with phenylmethyl ...201515675447
[the effect of g protein regulator on pollen germination and [ca2+]i variation in pyrus serotina rehd. pollen].the effects of the cholera toxin (ctx) and pertussis toxin (ptx), which can activate and antagonize respectively the heterotrimeric g protein, on pollen germination, pollen tube growth and the dynamic of cytosolic free calcium concentration ([ca(2+)]i) in pear pollen were investigated using laser confocal scanning microscope (lcsm). the results show that ctx could stimulate pollen germination and tube growth while ptx had the opposite effect. ctx and ptx had marked influence on the dynamic of po ...200515840934
analyses of arbutin and chlorogenic acid, the major phenolic constituents in oriental pear.the hplc retention time, photodiode array uv spectrum analysis, and lc/ms results indicated that arbutin and chlorogenic acid are the main phenolic constituents in oriental pear. the two compounds exist in different organs of the yali pear, which is one of the major cultivars of pyrus bretschnrideri. the contents of arbutin in the leaf bud, floral bud, flower, and young fruit were 11.9, 12.4, 8.29, and 9.92 mg/g fresh weight (fw), respectively. chlorogenic acid amounts in the same organs were 2. ...200515884812
isolation, characterization, and cloning of {alpha}-l-arabinofuranosidase expressed during fruit ripening of japanese pear.alpha-l-arabinofuranosidase (alpha-l-arafase) was purified from fruit of japanese pear (pyrus pyrifolia). the enzyme solubilized from the cell wall by nacl and triton x-100 had the homogeneity of a single 62-kd polypeptide on sds-page after purification through the steps of hydroxyapatite, anion-exchange chromatography, and size-exclusion chromatography. a related cdna clone was isolated (pparf2). the transcript and related protein were detected solely in the ripening fruit corresponding to the ...200515965025
13c-photosynthate accumulation in japanese pear fruit during the period of rapid fruit growth is limited by the sink strength of fruit rather than by the transport capacity of the pedicel.in japanese pear, the application of ga3+4 during the period of rapid fruit growth resulted in a marked increase in pedicel diameter and bigger fruit at harvest. to elucidate the relationship between pedicel capacity and fruit growth and to determine the main factor responsible for larger fruit size at harvest, fruit growth and pedicel vascularization after ga application were examined and the carbohydrate fluxes were monitored in a spur unit by non-invasive techniques using 13c tracer. histolog ...200516131508
induction of defense responses against alternaria rot by different elicitors in harvested pear fruit.pear fruit (pyrus pyrifolia l. cv. yali) treated by different elicitors, such as salicylic acid (sa), oxalic acid, calcium chloride, and antagonistic yeast cryptococcus laurentii, were investigated to determine the induction of defense responses. the possible mechanism by which elicitors induced the resistance of pear fruit against postharvest disease was also evaluated. the results indicated that all the elicitors could significantly enhance defense-related enzyme activities, such as beta-1,3-g ...200616158285
molecular evidence of sorbitol dehydrogenase in tomato, a non-rosaceae plant.the enzyme nad-dependent sorbitol dehydrogenase (sdh) is well characterized in the rosaceae family of fruit trees, which synthesizes sorbitol as a translocatable photosynthate. expressed sequence tags of sdh-like sequences have also been generated from various non-rosaceae species that do not synthesize sorbitol as a primary photosynthetic product, but the physiological roles of the encoded proteins in non-rosaceae plants are unknown. therefore, we isolated an sdh-like cdna (sdl) from tomato (ly ...200516289145
comparison between rosellinia necatrix isolates from soil and diseased roots in terms of hypovirulence.the white root rot fungus, rosellinia necatrix, is a devastating soil-borne pathogen of many plant species. biocontrol with the hypovirulence factor is promising, but disease symptoms, signs or culture morphology of the pathogen cannot be reliably used as markers for hypovirulence in this fungus. we attempted to obtain hypovirulent isolates from soil rather than from diseased roots, based on the hypothesis that hypovirulent isolates were more likely to persist in soil as saprobes. sixteen isolat ...200516332329
nuclear ribosomal dna as a probe for genetic variability in the japanese pear pathotype of alternaria alternata.a restriction fragment length polymorphism analysis of nuclear ribosomal rna genes (rdna) was used to measure the amount and distribution of genetic variability in populations of the japanese pear pathotype of alternaria alternata on both micro- and macrogeographical scales. a total of 322 isolates were obtained from 13 areas in aichi, gifu, and tottori prefectures in central and western japan. the restriction fragment length polymorphism analysis revealed that the pathogen populations contained ...199316349060
searching for a new putative cryptic virus in pinus sylvestris l.double-stranded rnas (dsrnas) were detected in different pine populations in germany and hungary. two dsrna species of 1.5 and 1.58 kbp, respectively, persisted in the same trees for at least 2 years and their presence was not associated with any symptoms. the dsrnas were found to sediment in the vlp (virus-like particles) fraction and to be protected by protein(s) against rnase a digestion at low salt. cdna cloning and sequencing of the smaller segment (dsrna2) led to the identification of a pu ...200616604450
overwintering phenology of a predacious mite, typhlodromus vulgaris (acari: phytoseiidae), on japanese pear trees, observed with phyto traps.phyto traps were attached to twigs, main branches and trunks of japanese pear trees in central japan in autumn of 2004, to evaluate the effectiveness of the trap as a tool to study overwintering phenology of arboreal phytoseiid mites. a subset of the traps was inspected and replaced at two-weeks intervals ("short-term phyto trap"), in order to evaluate movement of phytoseiid mites on the trees in a short-term. the remaining traps were left undisturbed and collected monthly from january to may 20 ...200616736277
genetic mapping of the pear scab resistance gene vnk of japanese pear cultivar kinchaku.pear scab (caused by venturia nashicola) is one of the most harmful diseases of pears, especially japanese and chinese pear species. the molecular identification and early selection of resistant plants could greatly improve pear breeding. we have identified the position of the scab resistance gene, designated vnk in an indigenous japanese pear cultivar kinchaku, within the pear genome by using simple sequence repeat (ssr) markers derived from pear and apple. the position of vnk was identified in ...200616838137
the impact of cell division and cell enlargement on the evolution of fruit size in pyrus pyrifolia.dramatic increases in fruit size have accompanied the domestication of pyrus pyrifolia. to evaluate the contribution of cell division and cell enlargement in the evolution of fruit size, the following study was conducted.200616845135
cloning of two isoforms of soluble acid invertase of japanese pear and their expression during fruit development.soluble acid invertase (s-aiv; ec 3.2.1.26) in japanese pear fruit has an important role in accumulating hexoses during fruit enlargement and regulates the sucrose-to-hexose ratio in the vacuole. full-length cdna of pss-aiv1 and pss-aiv2 isoforms were cloned from japanese pear fruit and their amino acid sequences share 40% identity; pss-aiv1 was confirmed to code s-aiv isozyme purified previously. the roles of pss-aiv1 and pss-aiv2 genes throughout fruit development and in sugar composition were ...200716884823
genetic differences between blight-causing erwinia species with differing host specificities, identified by suppression subtractive hybridization.pcr-based subtractive hybridization was used to isolate sequences from erwinia amylovora strain ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: e. amylovora mr1, which is pathogenic only on rubus spp.; erwinia pyrifoliae ep1/96, the causal agent of shoot blight of asian pears; and erwinia sp. strain ejp556, the causal agent of bacterial shoot blight of pear in japan. in total, six subtractive libraries were ...200616963554
changes in the volatile compounds and chemical and physical properties of kuerle fragrant pear (pyrus serotina reld) during storage.volatiles from stored kuerle fragrant pears (pyrus serotina reld) were studied using high-resolution gas chromatography and the solid-phase microextraction (spme) method of gas chromatography/mass spectrometry (gc/ms). the dominant components were hexanal, ethyl hexanoate, ethyl butanoate, ethyl acetate, hexyl acetate, ethanol, alpha-farnesene, butyl acetate, and ethyl (e,z)-2,4-decadienoate. by using gc-olfactometry, it demonstrated that the volatile compounds from spme were responsible for the ...200617090132
s locus f-box brothers: multiple and pollen-specific f-box genes with s haplotype-specific polymorphisms in apple and japanese pear.although recent findings suggest that the f-box genes sfb/slf control pollen-part s specificity in the s-rnase-based gametophytic self-incompatibility (gsi) system, how these genes operate in the system is unknown, and functional variation of pollen s genes in different species has been reported. here, we analyzed the s locus of two species of maloideae: apple (malus domestica) and japanese pear (pyrus pyrifolia). the sequencing of a 317-kb region of the apple s9 haplotype revealed two similar f ...200717237509
molecular identification of two new self-incompatible alleles (s-alleles) in chinese pear (pyrus bretschneideri).self-incompatibility (si) is an important intraspecific reproductive barrier in flowering plants. to identify the s-alleles of chinese pear species (pyrus pyrifolia, p. bretschneideri, p. ussuriensis and p. sinkiangenis etc.), s-rnase-specific pcr amplification, sequence analyses and field pollination tests were performed using two cultivars 'jingxiang' and 'esu' of p. bretschneideri as materials. two new s-rnase genes were identified from the two cultivars. they were 1,122 bp and 1,058 bp in le ...200717287571
identification of hyperpolarization-activated calcium channels in apical pollen tubes of pyrus pyrifolia.the pollen tube has been widely used to study the mechanisms underlying polarized tip growth in plants. a steep tip-to-base gradient of free cytosolic calcium ([ca(2+)](cyt)) is essential for pollen-tube growth. local ca(2+) influx mediated by ca(2+)-permeable channels plays a key role in maintaining this [ca(2+)](cyt) gradient. here, we developed a protocol for successful isolation of spheroplasts from pollen tubes of pyrus pyrifolia and identified a hyperpolarization-activated cation channel u ...200717447909
texture analysis of mr image for predicting the firmness of huanghua pears (pyrus pyrifolia nakai, cv. huanghua) during storage using an artificial neural network.firmness, a main index of quality changes, is important for the quality evaluation of fruits. in the present study, texture analysis (ta) of magnetic resonance images was applied to predict the firmness of huanghua pears (pyrus pyrifolia nakai, cv. huanghua) during storage using an artificial neural network (ann). seven co-occurrence matrix-derived ta parameters and one run-length matrix ta parameter significantly correlated with firmness were considered as inputs to the ann. several ann models ...200717540285
polymorphism of sfbb-gamma and its use for s genotyping in japanese pear (pyrus pyrifolia).japanese pear (pyrus pyrifolia) exhibits the s-rnase-based gametophytic self-incompatibility where the pollen-part determinant, pollen s, had long remained elusive. recent identification of s locus f-box brothers (sfbb) in japanese pear and apple suggested that the multiple f-box genes are the pollen s candidates as they exhibited pollen specific expression, s haplotype-specific polymorphisms and linkage to the s locus. in japanese pear, three sfbbs were identified from a single s haplotype, and ...200717541597
genetic mapping of genes for susceptibility to black spot disease in japanese pears.black spot disease, which is caused by the japanese pear pathotype of alternaria alternata (fr.) keissler, is one of the most harmful diseases in japanese pear cultivation. we identified the exact positions and linkage groups (lgs) of the genes for susceptibility to black spot in the japanese pear (pyrus pyrifolia nakai) cultivars 'osa nijisseiki' (gene ani) and 'nansui' (gene ana). segregation of susceptibility and resistance fitted the expected ratio of 1:1 in progeny of 'nansui' but showed a ...200717893733
high prevalence of pollinosis symptoms among the farmers cultivating japanese pears.in a district of japanese pear cultivators, a questionnaire survey and an ige antibody survey were conducted on the pollinosis. a high prevalence of 36.3 percent of the farmers complained of pollinosis symptoms. by the ige antibody survey, the symptoms were found to be related to the airborne pollens in the orchard.201717903353
allergenic pollens and spores in the working environment of japanese pear farmers.occupational allergies such as pollinosis are reported in several agricultural works in japan. many pollens and spores were observed in japanese pear orchard during the artificial pollination season. by the study on daily symptoms in an allergic farmer, we confirmed that the pollinosis symptoms were most common and most severe during the artificial pollination. these results suggest that the exposure to allergenic pollens and spores induces allergic symptoms. thus, caution should be paid for the ...201717903360
[effects of g-protein regulators and stylar s-rnase on the growth and ca2+ concentration of pyrus pyrifolia pollen tube].the effects of g protein regulators and stylar s-rnase on the growth and [ca(2+)](i) changes of the pyrus pyrifolia pollen tube were investigated using laser confocal scanning microscope (lcsm). the results indicated that: (1) the growth of 'housui' pollen tube could be inhibited by its stylar s-rnase and pertussis toxin (ptx), the inhibitor of heterotrimeric g protein. while 'kousui' stylar s-rnase had little effect on the growth of 'housui' pollen tube; cholera toxin (ctx), the activator of he ...200717960042
purification and characterization of a non-s-rnase and s-rnases from styles of japanese pear (pyrus pyrifolia).in this study we biochemically characterized stylar ribonucleases (rnases) of japanese pear (pyrus pyrifolia), which exhibits s-rnase-based gametophytic self-incompatibility. we separated the rnase fractions ns-1, ns-2, and ns-3 from stylar extracts of the cultivar nijisseiki (s(2)s(4)). the rnase in each fraction was purified to homogeneity through a series of chromatographic steps. chemical analysis of the proteins revealed that the basic rnases in the ns-2 and ns-3 fractions were the s(4)- an ...200717988882
pyrus pyrifolia stylar s-rnase induces alterations in the actin cytoskeleton in self-pollen and tubes in vitro.pears (pyrus pyrifolia l.) have an s-rnase-based gametophytic self-incompatibility system, and s-rnases have also been implicated in self-pollen or genetically identical pollen rejection. tip growth of the pollen tube is dependent on a functioning actin cytoskeleton. in this study, configurations of the actin cytoskeleton in p. pyrifolia pollen and effects of stylar s-rnases on its dynamics were investigated by fluorescence and confocal microscopy. results show that actin filaments in normal pol ...200718094928
deletion of a 236 kb region around s 4-rnase in a stylar-part mutant s 4sm-haplotype of japanese pear.japanese pear (pyrus pyrifolia nakai) has a gametophytic self-incompatibility (gsi) mechanism controlled by a single s-locus with multiple s-haplotypes, each of which contains separate genes that determine the allelic identity of pistil and pollen. the pistil s gene is the s-ribonuclease (s-rnase) gene, whereas good candidates for the pollen s gene are the f-box protein genes. a self-compatible (sc) cultivar, 'osa-nijisseiki', which is a bud mutant of 'nijisseiki' (s (2) s (4)), has a stylar-par ...200818175198
the genome of erwinia tasmaniensis strain et1/99, a non-pathogenic bacterium in the genus erwinia.the complete genome of the bacterium erwinia tasmaniensis strain et1/99 consisting of a 3.9 mb circular chromosome and five plasmids was sequenced. strain et1/99 represents an epiphytic plant bacterium related to erwinia amylovora and e. pyrifoliae, which are responsible for the important plant diseases fire blight and asian pear shoot blight, respectively. strain et1/99 is a non-pathogenic bacterium and is thought to compete with these and other bacteria when occupying the same habitat during i ...200818462403
phenolic compounds and chromatographic profiles of pear skins (pyrus spp.).a standardized profiling method based on liquid chromatography with diode array and electrospray ionization/mass spectrometric detection (lc-dad-esi/ms) was used to analyze the phenolic compounds in the skins of 16 pears (pyrus spp.). thirty-four flavonoids and 19 hydroxycinnamates were identified. the main phenolic compounds (based on peak area) in all of the pear skins were arbutin and chlorogenic acid. the remaining phenolics varied widely in area and allowed the pears to be divided into four ...200818778075
s-rnase triggers mitochondrial alteration and dna degradation in the incompatible pollen tube of pyrus pyrifolia in vitro.pear (pyrus pyrifolia l.) has a s-rnase-based gametophytic self-incompatibility (si) mechanism, and s-rnase has also been implicated in the rejection of self-pollen and genetically identical pollen. no studies, however, have examined the extent of organelle alterations during the si response in pyrus pyrifolia. consequently, this study focused on the alterations to mitochondria and nuclear dna in incompatible pollen tubes of the pear. methylthiazolyldiphenyl-tetrazolium bromide was used to evalu ...200918786182
ultrastructural study on acibenzolar-s-methyl-induced scab resistance in epidermal pectin layers of japanese pear leaves.the infection behavior of japanese pear scab pathogen venturia nashicola race 1 was studied ultrastructurally in acibenzolar-s-methyl (asm)-pretreated susceptible japanese pear (cv. kousui) leaves to determine the mechanism of asm-induced scab resistance. on asm-pretreated leaf surfaces, the infection behavior (conidial germination and appressorial formation) was similar to that on distilled water (dw)-pretreated leaves prior to cuticle penetration by the pathogen. however, after penetration, di ...200818943227
worldwide phylogeography of the citrus brown spot pathogen, alternaria alternata.abstract sixty-five isolates of alternaria alternata were sampled from brown spot lesions on tangerines and mandarins (citrus reticulata) and tangerine x grapefruit (c. reticulata x c. paradisi) hybrids in the united states, colombia, australia, turkey, south africa, and israel to investigate the worldwide phylogeography of the fungus. genetic variation was scored at 15 putative random amplified polymorphic dna (rapd) loci and 465 bp of an endo-polygalacturonase (endo-pg) gene was sequenced for ...200218943277
acibenzolar-s-methyl-induced resistance to japanese pear scab is associated with potentiation of multiple defense responses.abstract this study reports the mode of action of acibenzolar-s-methyl (asm) against japanese pear scab, caused by venturia nashicola. pretreatment of potted japanese pear trees with asm reduced scab symptoms and potentiated several lines of plant defense response. this included transcripts encoding polygalacturonase-inhibiting protein (pgip) that were highly and transiently promoted after scab inoculation of plants pretreated with asm, suggesting a possible role for defenses involved in direct ...200418943485
duplex real-time polymerase chain reaction reveals competition between erwinia amylovora and e. pyrifoliae on pear blossoms.erwinia amylovora and e. pyrifoliae are the causative agents of fire blight and asian pear blight, respectively. the pathogens are closely related, with overlapping host ranges. data are unavailable on the current distribution of e. pyrifoliae and on the interaction between the two species when they are present together on the same host. in this study, a duplex real-time polymerase chain reaction (pcr) protocol was developed to monitor the population dynamics of e. amylovora and e. pyrifoliae on ...200818944291
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