towards monoclonal antibodies against the apple proliferation mycoplasma-like organism.a 6-week-old female balb/c mouse was immunized with a preparation of partially purified sieve tubes of periwinkle (catharantus roseus) plants infected with the apple proliferation mycoplasma-like organism. after fusion of the immunized spleen cells with myeloma cells, the supernatant fluids of the resulting hybridoma cultures were screened for the presence of antibodies in a differential avidin-biotin enzyme-linked immunosorbent assay (elisa) using sieve tube preparations from either healthy or ...19873667236
chromosomal organization and nucleotide sequence of the genes coding for the elongation factors g and tu of the apple proliferation phytoplasma.genes coding for elongation factors g (fus) and tu (tuf) of the non-culturable apple proliferation (ap) phytoplasma were cloned and sequenced. arrangement of these genes and identification of the ribosomal protein gene rps7 upstream of the fus gene suggest a transcriptional organization similar to that of the streptomycin operon of escherichia coli and other bacteria. the fus and tuf genes from other tested phytoplasmas were found to be similarly linked as in the ap agent. thus, it is likely tha ...19999889337
isolation of the gene encoding an immunodominant membrane protein of the apple proliferation phytoplasma, and expression and characterization of the gene immunodominant membrane protein (imp) of the apple proliferation (ap) phytoplasma was detected in preparations from ap-diseased periwinkle plants using monoclonal and polyclonal antibodies to the ap agent. following isolation from western blots and partial sequencing, degenerate oligonucleotides derived from the imp sequence were used as probes to identify a dna fragment containing the orf encoding the imp. complete sequencing and subsequent analysis of the cloned dna fragment revealed the pr ...199910463160
physical map of the chromosome of the apple proliferation phytoplasma.a physical map of the apple proliferation phytoplasma strain at chromosome was constructed from genomic dna extracted from diseased tobacco plants. the map was generated with single and double digestions of the chromosome with bsshii, smai, mlui, and apai restriction endonucleases and resolving the fragments by pulsed-field gel electrophoresis. partial digestion and southern blot analysis were used to assist in the arrangement of the 14 contiguous restriction fragments obtained. from the restric ...200010671466
genetic variability of apple proliferation phytoplasmas as determined by pcr-rflp and sequencing of a non-ribosomal proliferation phytoplasmas are considered as quarantine organisms in europe and north america, but reliable polymerase chain reaction (pcr) primers for their identification in routine diagnosis were missing, because they show genetic variability. therefore, 100 apple proliferation phytoplasma isolates, derived from most of the european countries where apple proliferation disease has been detected, were analysed for their genetic variability. a detailed restriction fragment length polymorph ...200010722788
a chromosome map of the european stone fruit yellows phytoplasma.a physical map of the european stone fruit yellows phytoplasma strain gsfy1 chromosome was constructed using pfge-purified genomic dna from diseased tobacco and tomato plants. the map was generated with single and double digestions of the chromosome with smai, bsshii, apai, bamhi and xhoi restriction endonucleases and the fragments were resolved by pfge. reciprocal double digestions were used to locate 26 restriction sites on the chromosome. southern blot analysis was also used to assist in the ...200111320124
population dynamics of cacopsylla melanoneura (homoptera: psyllidae), a vector of apple proliferation phytoplasma in northwestern proliferation is a phytoplasma-associated disease transmitted by insects causing serious damage and economic losses to apple orchards. investigations were carried out in 1999 and 2000 in northwestern italy to identify the vector of apple proliferation and to study its population dynamics. yellow sticky traps and beat tray samples revealed the presence of the psyllid cacopsylla melanoneura (forster) in eight apple orchards in the aosta valley. the species completes one generation per year; ...200212075998
comparison of different techniques for inoculation of "candidatus phytoplasma mali" on apple and periwinkle in biological indexing phytoplasmas are non cultivable micro-organisms, the research on phytoplasmal diseases can only be achieved with infected hosts. biological indexing (by grafting) is the simplest detection method for phytoplasmal diseases. we tested four different grafting techniques for inoculation of apple trees or periwinkles in greenhouse, including whip graft, bark graft, budding and chip-budding. all techniques were tested on apple trees (six trees per phytoplasma isolates) in insect-proof greenhouse. t ...200718396810
integrated management of phytoplasma diseases in pome fruit: an overview of efficacy results of ipm insecticides against pear psylla (cacopsylla pyri).phytoplasmas are plant pathogenic mollicutes that cause devastating diseases in various crops worldwide. the closely related pome fruit tree phytoplasmas candidatus phytoplasma mali and candidatus phytoplasma pyri are the causal agents of apple proliferation and pear decline, respectively. they can be transmitted from tree to tree by psyllidae. as pear suckers (cacopsylla pyri) are widely considered to be the most important pest in pear orchards, a good control of this insect vector is a key ele ...201021539243
an effector of apple proliferation phytoplasma targets tcp transcription factors-a generalized virulence strategy of phytoplasma?the plant pathogen candidatus phytoplasma mali (p. mali) is the causative agent of apple proliferation, a disease of increasing importance in apple-growing areas within europe. despite its economic importance, little is known about the molecular mechanisms of disease manifestation within apple trees. in this study, we identified two tcp (teosinte branched/cycloidea/proliferating cell factor) transcription factors of malus x domestica as binding partners of the p. mali sap11-like effector atp_001 ...201727037957
population dynamics of cacopsylla melanoneura (hemiptera: psyllidae) in northeast italy and its role in the apple proliferation epidemiology in apple the current study, incidence of 'candidatus phytoplasma mali' in an experimental apple orchard in northeast italy, in addition to abundance and phytoplasma infectivity of cacopsylla melanoneura (förster) (hemiptera: psyllidae) was determined and the role of this psyllid as a vector of 'ca. p. mali' in this region was reviewed. insect samples collected in the orchard by the beating method indicated high abundance of c. melanoneura (up to 7.92 specimens/branch); however, the psyllid c. picta wa ...201222606799
evagreen real-time pcr protocol for specific 'candidatus phytoplasma mali' detection and quantification in this paper the validation and implementation of a real-time pcr protocol based on ribosomal protein genes has been carried out for sensitive and specific quantification of 'candidatus (ca.) phytoplasma mali' (apple proliferation phytoplasma, app) in insects. the method combines the use of evagreen(®) dye as chemistry detection system and the specific primer pair rpap15f-mod/rpap15r3, which amplifies a fragment of 238 bp of the ribosomal protein rplv (rpl22) gene of app. primers specificity wa ...201323474195
gene expression and biochemical changes of carbohydrate metabolism in in vitro micro-propagated apple plantlets infected by 'candidatus phytoplasma mali'.'candidatus phytoplasma mali' (ca. p. mali) is the disease agent causing apple proliferation (ap), which has detrimental effects on production in many apple growing areas of central and southern europe. the present study investigated transcriptional and biochemical changes related to the sugar metabolism as well as expression of pathogenesis-related (pr) protein genes in in vitro micro-propagated ap-infected and healthy control plantlets with the aim of shedding light on host plant response to ' ...201323811119
transcriptomics assisted proteomic analysis of nicotiana occidentalis infected by candidatus phytoplasma mali strain at.phytoplasmas are pathogenic bacteria within the class of mollicutes, which are associated with more than 1000 plant diseases. in this study, we applied quantitative mass spectrometry to analyse affected pathways of the model plant tobacco (nicotiana occidentalis) upon candidatus phytoplasma mali strain at infection. using tissue obtained from leaf midribs, 1466 plant-assigned proteins were identified. for 1019 of these proteins, we could reproducibly quantify the expression changes of infected v ...201424920314
phytoplasma sap11 alters 3-isobutyl-2-methoxypyrazine biosynthesis in nicotiana benthamiana by suppressing nbomt1.phytoplasmas are bacterial phytopathogens that release virulence effectors into sieve cells and act systemically to affect the physiological and morphological state of host plants to promote successful pathogenesis. we show here that transgenic nicotiana benthamiana lines expressing the secreted effector sap11 from candidatus phytoplasma mali exhibit an altered aroma phenotype. this phenomenon is correlated with defects in the development of glandular trichomes and the biosynthesis of 3-isobutyl ...201627279277
candidate insect vectors of apple proliferation in northwest spain.the apple proliferation (ap) disease is spread mostly by two psyllids. each species plays a predominant role as ap vector that changes regionally. thus, there is an urgent need to identify the ap vectors in each region where the disease is present. this research aimed at identifying the psyllid community in apple orchards from asturias (nw spain) and studying their possible role in ap transmission. yellow sticky traps were used to monitor psyllid community in five cider-apple orchards during 2 y ...201627536523
characteristics of the spread of apple proliferation by its vector cacopsylla picta.the distribution and natural phytoplasma infection of cacopsylla picta were investigated during a long-term field survey between 2002 and 2009 in commercial and abandoned apple proliferation-infected orchards throughout germany, northern switzerland, and eastern france. comparable population dynamics were described for the different sites whereas considerable variations in the absolute population densities were observed among the years. individual polymerase chain reaction (pcr) testing revealed ...201121848395
phytopathogen lures its insect vector by altering host plant odor.many phytopathogens that cause worldwide losses of agricultural yield are vectored by herbivorous insects. limited information is available about the interactions among phytopathogens, host plants, and insect vectors. in this paper, we report that the cell wall-lacking bacterium candidatus phytoplasma mali can alter both the odor of its host plant (apple) and behavior of its vector, the univoltine psyllid cacopsylla picta. apple trees infected by this phytoplasma emitted higher amounts of beta-c ...200818600377
establishment of a new method for rapid and precise estimation of apple proliferation phytoplasma concentration in periwinkle.quantification of a plant pathogen is essential to study its population dynamic in various conditions and to relate symptom expression with pathogen concentration. up to now, very few methods have been published to quantify phytoplasmas. so, the objective of this work was to establish a method able to quantify the apple proliferation (ap) phytoplasma populations in periwinkles. the present work was based on a method previously published to detect ap phytoplasma. this method was optimized to tran ...200617390831
multilocus sequences confirm the close genetic relationship of four phytoplasmas of peanut witches'-broom group 16srii-a.four witches'-broom diseases associated with arachis hypogaea (peanut), crotalaria pallida, tephrosia purpurea, and cleome viscosa were observed in hainan province, china during field surveys in 2004, 2005, and 2007. in previously reported studies, we identified these four phytoplasmas as members of subgroup 16srii-a, and discovered that their 16s rrna gene sequences were 99.9-100% identical to one another. in this study, we performed extensive phylogenetic analyses to elucidate relationships am ...201423686459
hflb gene-based phytopathogenic classification of 'candidatus phytoplasma mali' strains and evidence that strain composition determines virulence in multiply infected apple trees.analysis of pathological and molecular data of 'candidatus phytoplasma mali' accessions from 27 apple trees differing considerably in symptomatology was used to molecularly characterize and classify strains of the infecting apple proliferation phytoplasma. single-strand conformation polymorphism and sequence analysis of a variable fragment of atp00464-type hflb gene revealed that these sources consisted of single-strain and multiple-strain accessions that occurred in similar numbers. the latter ...201121899439
pathogen-induced release of plant allomone manipulates vector insect behavior.infochemicals mediate communication within and between different trophic levels. in this study, we identified a new type of plant allomone induced by a plant pathogen and perceived by its vector insect cacopsylla picta. this phloem-feeding psyllid is the main vector of candidatus phytoplasma mali, a cell wall-lacking bacterium that causes the so-called apple proliferation disease. in a previous study, we showed that newly emerged females of c. picta were attracted by the odor of phytoplasma-infe ...200819031034
range of phytoplasma concentrations in various plant hosts as determined by competitive polymerase chain reaction.abstract for competitive polymerase chain reaction (pcr), an internal standard dna template was developed that consisted of a highly conserved, internally deleted 16s rdna fragment of an aster yellows phytoplasma. the internal standard was calibrated using a quantified culture of acholeplasma laidlawii. serial dilutions of the internal standard and fixed amounts of target templates from infected plants were coamplified with the same primers, and the products obtained were quantified using an enz ...200018944479
recovery in apple trees infected with the apple proliferation phytoplasma: an ultrastructural and biochemical study.abstract localization of hydrogen peroxide (h(2)o(2)) and the roles of peroxidases, malondialdehyde, and reduced glutathione in three apple cultivars were compared in healthy trees, trees infected with apple proliferation phytoplasma (app), and trees that had recovered from the infection. in recovered apple trees, symptoms of the disease and the pathogen had disappeared from the canopy, but phytoplasmas remained in the roots. h(2)o(2) was detected cytochemically by its reaction with cerium chlor ...200418943544
transmission of apple proliferation phytoplasma by cacopsylla melanoneura (homoptera: psyllidae).transmission trials of apple proliferation (ap) phytoplasma to healthy apple plants were carried out with cacopsylla melanoneura (forster). both field naturally infected and experimentally infected psyllids were evaluated. the capacity of the different life stages of the insect in transmitting ap was tested. overwintered adults collected in the orchards were able to transmit ap with a variable efficiency, depending on the infectivity rate of source plants. experimentally infected nymphs and spri ...200414998121
evaluation of different insecticides and strategies against cacopsylla melanoneura (förster) (homoptera: psyllidae), a vector of apple proliferation phytoplasma. 200718399470
effectiveness of five insecticides for the control of adults and young stages of cacopsylla melanoneura (förster) (hemiptera: psyllidae) in a semi-field trial.cacopsylla melanoneura (förster) is a vector of candidatus phytoplasma mali, the causal agent of one of the most serious diseases in european apple orchards, apple proliferation (ap). the aim of this study was to evaluate the toxicity of five insecticides from different chemical groups (carbamates, chitin inhibitors, insect growth regulators, organophosphates and pyrethroids) towards overwintered adults and young stages of c. melanoneura under semi-field conditions.201019937976
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