Viroids
Mostrando 1-12 de 80 artigos, teses e dissertações.
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1. Identification and characterization of viroids in 'Navelina ISA 315' sweet orange
To date, seven species of viroids have been described infecting Citrus. However, only Citrus exocortis viroid (CEVd), Hop stunt viroid (HSVd) and Citrus dwarfing viroid (CDVd) have been reported in this crop in Brazil. The aim of our work was to identify and characterize viroids infecting plants of 'Navelina ISA 315' sweet orange cultivar grafted on 'Rangpur
Trop. plant pathol.. Publicado em: 2013-02
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2. Viroids in Tahiti lime scions showing back cracking symptoms.
The so-called "quebra-galho" clone of Tahiti lime is very popular in Brazil, because the small size of the trees is suitable for high-density plantings. These Tahiti lime trees are easily recognized because they show bark-cracking symptoms, that have been claimed to be associated with "exocortis" infection. Viroid infection of three "quebra-galho" Tahiti lim
CONFERENCE OF THE INTERNATIONAL ORGANIZATION OF CITRUS VIROLOGISTS. Publicado em: 2011
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3. Sequence analysis of three citrus viroids infecting a single Tunisian citrus tree (Citrus, reticulata, Clementine)
We report the nucleotide sequences of three citrus viroids belonging to three different genera: Citrus exocortis viroid (CEVd), Hop stunt viroid (HSVd) and Citrus viroid-III (CVd-III) isolated from a single natural infected Citrus reticulata var. Clementine tree growing in a tree nursery in Manouba (near Tunis Capital). We describe the sequence variability o
Genetics and Molecular Biology. Publicado em: 2006
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4. Identificação e caracterização de viróides e estudo de alguns aspectos da interação de viróides com proteínas do hospedeiro / Identification and characterization of viroids and study of some viroid-host protein interactions
The present work has been divided into four chapters to: (i) review the main points in viroid-host interactions and present different aspects in the evolutionary relationship of the viroids and virusoids; (ii) identify and characterize viroids infecting grapevine in Brazil; (iii) purify, clone and sequence what appears to be a novel citrus viroid; (iv) study
Publicado em: 2006
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5. Structural similarities between viroids and transposable genetic elements.
The primary structures of the tomato planta macho and tomato apical stunt viroids have been determined, and probable secondary structures are proposed. Both viroids can assume the rodlike conformation with extensive base-pairing characteristic of all known viroids. Sequence homologies between the two viroids (75%) and with members of the potato spindle tuber
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6. Viroids are single-stranded covalently closed circular RNA molecules existing as highly base-paired rod-like structures.
Viroids are uncoated infectious RNA molecules pathogenic to certain higher plants. Four different highly purified viroids were studied. By ultracentrifugation, thermal denaturation, electron microscopy, and end group analysis the following features were established: (i) the molecular weight of cucumber pale fruit viroid from tomato is 110,000, of citrus exoc
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7. Inosine 5'-triphosphate can dramatically increase the yield of NASBA products targeting GC-rich and intramolecular base-paired viroid RNA.
Nucleic acid sequence-based amplification (NASBA) according to the standard protocol failed to amplify cRNA of viroids, probably because of their GC-rich and intramolecular base-paired structure. However, NASBA in the presence of inosine 5'-triphosphate successfully amplified the cRNAs to viroids in total nucleic acid extracts from citrus plants. As sequence
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8. Domains in viroids: evidence of intermolecular RNA rearrangements and their contribution to viroid evolution.
On the basis of sequence homology a model is proposed for five structural and functional domains in viroids. These domains include (i) a conserved central region capable of forming two alternative structures that may regulate two phases of the viroid replication cycle, (ii) a region associated with pathogenicity, (iii) a domain with high sequence variability
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9. Comparative oligonucleotide fingerprints of three plant viroids.
5' Phosphorylation in vitro with gamma-32P-ATP and T4 phage induced polynucleotide kinase was used to obtain RNAase A and RNAase T1 fingerprints of three plant viroids: Potato spindle tuber viroid from tomato (PSTV-tom), chrysanthemum stunt viroid from cineraria (ChSV-cin) and citrus exocortis viroid from Gynura aurantiaca (CEV-gyn). These three viroids diff
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10. Prominent polypurine and polypyrimidine tracts in plant viroids and in RNA of the human hepatitis delta agent.
To seek patterns of nucleotide usage in the three types of circular subviral RNA pathogens, trimer frequencies and nearest-neighbor biases were studied in 12 plant viroid sequences; five sequences of circular plant viral satellite RNAs; and the sequence of RNA from the human hepatitis delta agent. The viroids and RNA of the delta agent contain tracts of poly
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11. Arabidopsis thaliana has the enzymatic machinery for replicating representative viroid species of the family Pospiviroidae
Viroids, subviral noncoding RNAs, replicate, move, and incite diseases in plants. Viroids replicate through a rolling-circle mechanism in which oligomeric RNAs of one or both polarities are cleaved and ligated into the circular monomers. Attempts to transmit viroids to Arabidopsis have failed for unknown reasons. To tackle this question, Arabidopsis was tran
National Academy of Sciences.
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12. Nucleotide sequence and proposed secondary structure of Columnea latent viroid: a natural mosaic of viroid sequences.
The Columnea latent viroid (CLV) occurs latently in certain Columnea erythrophae plants grown commercially. In potato and tomato, CLV causes potato spindle tuber viroid (PSTV)-like symptoms. Its nucleotide sequence and proposed secondary structure reveal that CLV consists of a single-stranded circular RNA of 370 nucleotides which can assume a rod-like struct