| Autor: |
Jackson, Robert W., Mansfield, John W., Ammouneh, Hassan, Dutton, Lindsay C., Wharton, Becky, Ortiz-Barredo, Amaya, Arnold, Dawn L., Tsiamis, George, Sesma, Ane, Butcher, Diane, Boch, Jens, Kim, Young Jin, Martin, Gregory B., Tegli, Stefania, Murillo, Jesús, Vivian, Alan |
| Předmět: |
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| Zdroj: |
Molecular Plant Pathology; Jul2002, Vol. 3 Issue 4, p205-216, 12p |
| Abstrakt: |
Summary virPphA is a major determinant of the pathogenicity of Pseudomonas savastanoi pv. phaseolicola to Phaseolus bean. A family of homologues of virPphA was detected in pathovars of P . savastanoi and P . syringae . We examined the structure and activity of alleles designated virPphA , virPphA Pgy , and virPphA Psv from P . savastanoi pathovars phaseolicola , glycinea , and savastanoi , respectively, and avrPtoB from P . syringae pv. tomato . Sequencing showed that the virPphA Pgy homologue had a 48-bp central deletion in the open reading frame (ORF) compared with virPphA and virPphA Psv , but otherwise all three P . savastanoi alleles had > 98% identity at the DNA level. By contrast, AvrPtoB from P . syringae pv. tomato strain DC3000 was predicted to have only 51% amino acid similarity with VirPphA. All ORFs have an upstream hrp -box promoter indicating potential regulation by HrpL. Each cloned homologue was introduced into the P. savastanoi pv. phaseolicola strain RW60, which lacks a native plasmid carrying virPphA as part of a pathogenicity island (PAI), and which is not pathogenic on bean. The homologues all restored virulence, as measured by the development of water-soaked lesions in bean pods, and increased bacterial populations in leaves compared with RW60 alone. RW60 harbouring virPphA or virPphA Psv elicited a strong hypersensitive reaction (HR) in soybean cv. Osumi; the presence of avrPtoB caused a weak HR, but virPphA Pgy did not affect the null reaction observed in soybean with RW60 alone. A second effector gene, avrPphD , was detected on the genomic clones carrying virPphA Pgy and virPphA Psv . avrPphD was also present in both P . savastanoi pv. phaseolicola and P . syringae pv. tomato , but elsewhere in their genomes. Comparison of the genomic locations of virPphA and other effectors found in the P. savastanoi pv. phaseolicola PAI revealed the... [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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