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Serological reactivity to Plum pox virus (PPV) antisera has been described in several Prunus sources of Asian origin that are free of PPV infection. Using polyvalent or specific PCR assays, the presence of three closely related ag...
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Serological reactivity to Plum pox virus (PPV) antisera has been described in several Prunus sources of Asian origin that are free of PPV infection. Using polyvalent or specific PCR assays, the presence of three closely related agents in two of these sources, Prunus mume cv. Bungo and P. persica cv. Ku Chu'a Hung, was demonstrated. Similarities in genome organization and sequence comparisons indicate that these agents should be regarded as members of the genus Foveavirus, their only singular trait being a very large (>800 nt) 3' non-coding region (NCR), as compared to the ca. 130-180 nt 3' NCR observed in other Foveaviruses. The three agents are very divergent from known Foveaviruses but are also significantly removed one from the others, with overall nucleotide sequence identity levels in the sequenced region of ca. 74-76% and of only 60.8-67.5% in their complete CP gene (61.9-71.3% amino acid sequence identity). Given the species discrimination criteria in the family Flexiviridae, these three agents should be regarded as three related yet distinct new viruses belonging to the Foveavirus genus, for which the names Asian prunus virus 1, 2 and 3 are proposed. Evidence is provided for the presence of variants of these new viruses in other Prunus germplasm of Asian origin.
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Double suppression subtractive hybridization was used to isolate DNA from 'Candidatus Phytoplasma prunorum' (GSFY2) propagated on Catharanthus roseus. Among the 11 new non-ribosomal genetic loci characterized, aceF and pnp genes w...
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Double suppression subtractive hybridization was used to isolate DNA from 'Candidatus Phytoplasma prunorum' (GSFY2) propagated on Catharanthus roseus. Among the 11 new non-ribosomal genetic loci characterized, aceF and pnp genes were selected as targets for detection and sequence typing. PCR primers chosen on aceF and pnp genes allowed to amplify the expected PCR products of 797 bp and 549 bp from the GSFY2 isolate as well as the homologous genetic loci from reference phytoplasma isolates of the group 16SrX. Sequences of aceF PCR products revealed a 13.7-15.5% variation between 'Ca. P. prunorum', 'Ca. P. pyri' and 'Ca. P. mali', which could be distinguished by specific sequence insertions or deletions. Four different groups of 'Ca. P. prunorum' isolates could be detected and discriminated in France according to their ace F sequence. 'Ca. P. prunorum' isolates B7, E22, PVCLA8 and PVCLA9, known to be associated with low level of symptom expression and formerly shown to provide cross protection to inoculated trees or peach seedlings against virulent isolates, had the same aceF sequence, which was one and two nucleotides different from the aceF sequence of the B6, GSFY, G32 and ECAM200 virulent isolates. A 'Ca. P. prunorum' plum isolate detected in Azerbaijan was much more different than the isolates detected in France (10-11 nucleotide changes). The greater variability in aceF relative to pnp makes aceF a better target for monitoring the variability among phytoplasmas infecting temperate fruit trees in Europe.
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Proteasomes have been purified from sunflower hypocotyles. They elute with a molecular mass of 600 kDa from gel filtration columns and two-dimensional gel electrophoresis indicates that the complex contains at least 20 different p...
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Proteasomes have been purified from sunflower hypocotyles. They elute with a molecular mass of 600 kDa from gel filtration columns and two-dimensional gel electrophoresis indicates that the complex contains at least 20 different protein subunits. Peptide microsequencing revealed the presence of four subunits homologous to subunits Beta2, Beta6, Alpha5 and Alpha6 of plant proteasomes. These proteasomes have chymotrypsin-like activity and the highly purified fraction of this complex i associated with an endonuclease activity hydrolyzing Tobacco mosaic virus RNA and Lettuce mosaic virus RNA wit a cleavage pattern showing fragments of well-define size. this is the first evidence of a RNA endonuclease activity associated with plant proteasomes.
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Many scientists, if not all, feel that their particular plant virus should appear in any list of the most important plant viruses. However, to our knowledge, no such list exists. The aim of this review was to survey all plant viro...
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Many scientists, if not all, feel that their particular plant virus should appear in any list of the most important plant viruses. However, to our knowledge, no such list exists. The aim of this review was to survey all plant virologists with an association with Molecular Plant Pathology and ask them to nominate which plant viruses they would place in a 'Top 10' based on scientific/economic importance. The survey generated more than 250 votes from the international community, and allowed the generation of a Top 10 plant virus list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Tobacco mosaic virus, (2) Tomato spotted wilt virus, (3) Tomato yellow leaf curl virus, (4) Cucumber mosaic virus, (5) Potato virus Y, (6) Cauliflower mosaic virus, (7) African cassava mosaic virus, (8) Plum pox virus, (9) Brome mosaic virus and (10) Potato virus X, with honourable mentions for viruses just missing out on the Top 10, including Citrus tristeza virus, Barley yellow dwarf virus, Potato leafroll virus and Tomato bushy stunt virus. This review article presents a short review on each virus of the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant virology community, as well as laying down a benchmark, as it will be interesting to see in future years how perceptions change and which viruses enter and leave the Top 10.Digital Object Identifier http://dx.doi.org/10.1111/j.1364-3703.2011.00752.x
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