| a plasmid isolated from phytopathogenic onion yellows phytoplasma and its heterogeneity in the pathogenic phytoplasma mutant. | a 3.6-kbp dna fragment was cloned from the extrachromosomal dna of a pathogenic plant mollicute, onion yellows phytoplasma (oy-w). sequence analysis of the fragment revealed an open reading frame (orf) encoding the replication (rep) protein of rolling-circle replication (rcr)-type plasmids. this result suggests the existence of a plasmid (poyw1) in oy-w that uses the rcr mechanism. this assumption was confirmed by detecting the single-stranded dna (ssdna) of a replication intermediate that is sp ... | 1998 | 9805390 |
| in planta expression of a protein encoded by the extrachromosomal dna of a phytoplasma and related to geminivirus replication proteins. | a new extrachromosomal dna, ecoyw1, was cloned from the onion yellows phytoplasma (oy-w). southern blot and pcr analysis showed that ecoyw1 is not present in the oy-m, a mild symptom line derived from oy-w. we determined the complete nucleotide sequence of ecoyw1; it is a circular dsdna of 7.0 kbp in length, which contains seven orfs. orf1 encoded a homologue of the geminivirus rep protein. western immunoblot analysis revealed that this rep homologue is expressed in oy-w infected plants, suggest ... | 2001 | 11158368 |
| two different thymidylate kinase gene homologues, including one that has catalytic activity, are encoded in the onion yellows phytoplasma genome. | thymidylate kinase (tmk) catalyses the phosphorylation of dtmp to form dtdp in both the de novo and salvage pathways of dttp synthesis in both prokaryotes and eukaryotes. two homologues of bacterial thymidylate kinase genes were identified in a genomic library of the onion yellows (oy) phytoplasma, a plant pathogen that inhabits both plant phloem and the organs of insects. southern blotting analysis suggested that the oy genome contained one copy of the tmk-b gene and multiple copies of the tmk- ... | 2003 | 12904564 |
| comparative analysis of the plasmids from two isolates of "candidatus phytoplasma australiense". | two plasmids from the plant-pathogenic mollicute "candidatus phytoplasma australiense" were completely sequenced from two isolates derived from different plant hosts. plasmid ppaph2 (3607bp) was obtained from phormium showing phormium yellow leaf symptoms and ppasb11 (3635bp) from strawberry showing strawberry lethal yellows symptoms. the plasmids varied in their copy number and nucleotide sequence yet contained the same four open reading frames (orfs). the deduced amino acid sequence derived fr ... | 2006 | 16620976 |
| in the non-insect-transmissible line of onion yellows phytoplasma (oy-nim), the plasmid-encoded transmembrane protein orf3 lacks the major promoter region. | 'candidatus phytoplasma asteris', onion yellows strain (oy), a mildly pathogenic line (oy-m), is a phytopathogenic bacterium transmitted by macrosteles striifrons leafhoppers. oy-m contains two types of plasmids (ecoym and poym), each of which possesses a gene encoding the putative transmembrane protein, orf3. a non-insect-transmissible line of this phytoplasma (oy-nim) has the corresponding plasmids (ecoynim and poynim), but poynim lacks orf3. here we show that in oy-m, orf3 is transcribed from ... | 2009 | 19372166 |
| unique morphological changes in plant pathogenic phytoplasma-infected petunia flowers are related to transcriptional regulation of floral homeotic genes in an organ-specific manner. | abnormal flowers are often induced by infection of certain plant pathogens, e.g. phytoplasma, but molecular mechanisms underlying these malformations have remained poorly understood. here, we show that the infection of oy-w phytoplasma (candidatus phytoplasma asteris oy-w) affects the expressions of floral homeotic genes of petunia plants in an organ specific manner. floral morphological changes including conversion to leaf-like structures were observed in sepals, petals and pistils, but not in ... | 2011 | 21605209 |
| two high-copy plasmids found in plants associated with strains of "candidatus phytoplasma asteris" | complete sequences for two plasmids associated with two strains of "candidatus phytoplasma asteris" have been obtained. the plasmid named pparg1 was found in rehmannia glutinosa l. associated with phytoplasma classified in the 16sr i-c subgroup. plasmid ppabn1 was from phytoplasma associated with infected winter oilseed rape and classified in the 16sr i-b subgroup. the plasmids pparg1 (4371 nt) and ppabn1 (3529 nt) have high a+t content of about 75%, similar to that of phytoplasma genomes. six a ... | 2011 | 21723316 |
| 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 ... | 2014 | 23686459 |
| in planta dynamic analysis of onion yellows phytoplasma using localized inoculation by insect transmission. | abstract due to the lack of a means to inoculate plants mechanically, the histological dynamics and in planta spread of phytoplasmas have been studied very little. we analyzed the dynamics of plant infection by phytoplasmas, using a technique to infect a limited area of a leaf, nested polymerase chain reaction (pcr), real-time pcr, and immunohistochemical visualization. following localized inoculation of a leaf of garland chrysanthemum (chrysanthemum coronarium) by the vector leafhopper macroste ... | 2004 | 18943972 |
| an antibody against the seca membrane protein of one phytoplasma reacts with those of phylogenetically different phytoplasmas. | abstract antisera raised against phloem-limited phytoplasmas generally react only with the phytoplasma strain used to produce the antigen. there is a need for an antiserum that reacts with a variety of phytoplasmas. here, we show that an antiserum raised against the seca membrane protein of onion yellows phytoplasma, which belongs to the aster yellows 16s-group, detected eight phytoplasma strains from four distinct 16s-groups (aster yellows, western x, rice yellow dwarf, and elm yellows). in imm ... | 2004 | 18943899 |
| isolation and characterization of derivative lines of the onion yellows phytoplasma that do not cause stunting or phloem hyperplasia. | abstract two lines of onion yellows phytoplasma producing milder symptoms were isolated from the original line (oy-w). one has an additional characteristic, non-insect-transmissibility (oy-nim), compared with the other (oy-m). oy-m was established after maintaining oy-w for 11 years on a plant host (chrysanthemum coronarium) with an insect vector (macrosteles striifrons), and oy-nim was isolated after subsequent maintenance of oy-m in plants by periodic grafting. polymerase chain analysis sugges ... | 2001 | 18943436 |
| cloning and characterization of the antigenic membrane protein (amp) gene and in situ detection of amp from malformed flowers infected with japanese hydrangea phyllody phytoplasma. | a japanese hydrangea phyllody (jhp) disease found throughout japan causes economic damage to the horticultural industry. jhp phytoplasma-infected japanese hydrangea plants show several disease symptoms involved in floral malformations, such as virescence, phyllody and proliferation. here, we cloned and characterized the antigenic membrane protein (amp) gene homolog from the jhp phytoplasma (jhp-amp), expressed the jhp-amp protein in escherichia coli cells, and then obtained an antibody against j ... | 2008 | 18943252 |
| living with genome instability: the adaptation of phytoplasmas to diverse environments of their insect and plant hosts. | phytoplasmas ("candidatus phytoplasma," class mollicutes) cause disease in hundreds of economically important plants and are obligately transmitted by sap-feeding insects of the order hemiptera, mainly leafhoppers and psyllids. the 706,569-bp chromosome and four plasmids of aster yellows phytoplasma strain witches' broom (ay-wb) were sequenced and compared to the onion yellows phytoplasma strain m (oy-m) genome. the phytoplasmas have small repeat-rich genomes. this comparative analysis revealed ... | 2006 | 16672622 |
| accumulation of pathogenesis-related type-5 like proteins in phytoplasma-infected garland chrysanthemum chrysanthemum coronarium. | soluble proteins extracted from leaves, apical shoots, axillary shoots, and stems of garland chrysanthemum plants infected by onion yellows phytoplasma were analyzed by two-dimensional gel electrophoresis. computerized matching analysis revealed that at least six soluble proteins were accumulated specifically in phytoplasma-infected garland chrysanthemum. n-terminal amino acids sequences of these soluble proteins, determined by edman degradation, shared high sequence similarities with those of p ... | 2004 | 15514852 |
| secretion of immunodominant membrane protein from onion yellows phytoplasma through the sec protein-translocation system in escherichia coli. | a gene that encodes a putative sece protein, which is a component of the sec protein-translocation system, was cloned from the onion yellows phytoplasma (oy). the identification of this gene and the previously reported genes encoding seca and secy provides evidence that the sec system exists in phytoplasma. in addition, a gene encoding an antigenic membrane protein (amp) (a type of immunodominant membrane protein) of oy was cloned and sequenced. the oy amp gene consisted of 702 nt encoding a pro ... | 2004 | 14702406 |
| identification of genes in the tomato big bud phytoplasma and comparison to those in sweet potato little leaf-v4 phytoplasma. | genetic relatedness of phytoplasmas is commonly defined on the basis of differences in the highly conserved 16s rrna gene, which may not resolve closely related phytoplasmas. an example of this is the closely related tomato big bud (tbb) and sweet potato little leaf strain v4 (spll-v4) phytoplasmas, which cannot easily be differentiated by their 16s rrna gene sequences. this study aimed to identify genes on the tbb phytoplasma chromosome which could be used to examine genetic variation between t ... | 2003 | 12855731 |
| complete nucleotide sequence of the s10-spc operon of phytoplasma: gene organization and genetic code resemble those of bacillus subtilis. | an 11.4-kbp region of genomic dna containing the complete s10-spc operon was constructed by an integrative mapping technique with eight plasmid vectors carrying ribosomal protein sequences from onion yellows phytoplasma. southern hybridization analysis indicated that phytoplasmal s10-spc is a single-copy operon. this is the first complete s10-spc operon of a phytoplasma to be reported, although only a part of six serial genes of the s10 operon is reported previously. the operon has a context of ... | 2002 | 12162807 |
| cloning and expression analysis of phytoplasma protein translocation genes. | genes encoding seca and secy proteins, essential components of the sec protein translocation system, were cloned from onion yellows phytoplasma, an unculturable plant pathogenic bacterium. the seca gene consists of 2,505 nucleotides encoding an 835 amino acid protein (95.7 kda) and shows the highest similarity with seca of bacillus subtilis. anti-seca rabbit antibody was prepared from a purified partial seca protein, with a histidine tag expressed in escherichia coli. western blot analysis confi ... | 2001 | 11551069 |
| a plasmid of phytoplasma encodes a unique replication protein having both plasmid- and virus-like domains: clue to viral ancestry or result of virus/plasmid recombination? | the genomes of most prokaryotic and eukaryotic single-stranded (ss) dna viruses, and some prokaryotic plasmids such as pls1, commonly replicate via a rolling circle replication (rcr) strategy, and thus the viruses are hypothesized to have evolved from the plasmids, although evidence for this view is sparse. we have sequenced a circular plasmid of 3933 nt, poyw, obtained from onion yellows phytoplasma (oy-w), a cell-wall-less, unculturable prokaryote that inhabits the cytoplasm of both plant and ... | 2001 | 11437661 |
| analysis of metabolic evolution in bacteria using whole-genome metabolic models. | recent advances in the automation of metabolic model reconstruction have led to the availability of draft-quality metabolic models (predicted reaction complements) for multiple bacterial species. these reaction complements can be considered as trait representations and can be used for ancestral state reconstruction to infer the most likely metabolic complements of common ancestors of all bacteria with generated metabolic models. we present here an ancestral state reconstruction for 141 extant ba ... | 2013 | 23992299 |
| accommodation of profound sequence differences at the interfaces of eubacterial rna polymerase multi-protein assembly. | evolutionarily divergent proteins have been shown to change their interacting partners. rna polymerase assembly is one of the rare cases which retain its component proteins in the course of evolution. this ubiquitous molecular assembly, involved in transcription, consists of four core subunits (alpha, beta, betaprime, and omega), which assemble to form the core enzyme. remarkably, the orientation of the four subunits in the complex is conserved from prokaryotes to eukaryotes although their seque ... | 2012 | 22359428 |