In Pseudomonas syringae pv. phaseolicola the Synthesis of Phaseolotoxin and the Concurrent Expression of the argK Gene Coding for the Phaseolotoxin-Resistant Ornithyl-Carbamoyl Transferase Occur Independent of the Global Arginine Regulator ArgR

Isolation and Characterization of the Gene Coding for the Amidinotransferase Involved in the Biosynthesis of Phaseolotoxin in Pseudomonas syringae pv. phaseolicola

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.4.545 ◽

2001 ◽

Vol 14 (4) ◽

pp. 545-554 ◽

Cited By ~ 37

Author(s):

Gustavo Hernández-Guzmán ◽

Ariel Alvarez-Morales

Keyword(s):

Aspartic Acid ◽

Pseudomonas Syringae ◽

Sequence Similarity ◽

Insertion Mutant ◽

Halo Blight ◽

Streptomyces Spp ◽

Isolation And Characterization ◽

Gene Coding ◽

Blight Disease

Pseudomonas syringae pv. phaseolicola is the causal agent of the “halo blight” disease of beans. A key component in the development of the disease is a nonhost-specific toxin, Nδ-(N'-sulphodiaminophosphinyl)-ornithyl-alanyl-homoarginine, known as phaseolotoxin. The homoarginine residue in this molecule has been suggested to be the product of Larginine:lysine amidinotransferase activity, previously detected in extracts of P. syringae pv. phaseolicola grown under conditions of phaseolotoxin production. We report the isolation and characterization of an amidinotransferase gene (amtA) from P. syringae pv. phaseolicola coding for a polypeptide of 362 residues (41.36 kDa) and showing approximately 40% sequence similarity to Larginine:inosamine-phosphate amidinotransferase from three species of Streptomyces spp. and 50.4% with an Larginine:glycine amidinotransferase from human mitochondria. The cysteine, histidine, and aspartic acid residues involved in substrate binding are conserved. Furthermore, expression of the amtA and argK genes and phaseolotoxin production occurs at 18°C but not at 28°C. An amidinotransferase insertion mutant was obtained that lost the capacity to synthesize homoarginine and phaseolotoxin. These results show that the amtA gene isolated is responsible for the amidinotransferase activity detected previously and that phaseolotoxin production depends upon the activity of this gene.

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The gene coding for the Hrp pilus structural protein is required for type III secretion of Hrp and Avr proteins in Pseudomonas syringae pv. tomato

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.040570097 ◽

2000 ◽

Vol 97 (5) ◽

pp. 2247-2252 ◽

Cited By ~ 88

Author(s):

W. Wei ◽

A. Plovanich-Jones ◽

W.-L. Deng ◽

Q.-L. Jin ◽

A. Collmer ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Type Iii Secretion ◽

Structural Protein ◽

Type Iii ◽

Gene Coding

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Effects of the pseudomonad phytotoxin coronatine on tomato leaf structure and ultrastructure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140683 ◽

1995 ◽

Vol 53 ◽

pp. 862-863

Author(s):

D.A. Palmer ◽

C.L. Bender

Keyword(s):

Pseudomonas Syringae ◽

Membrane Integrity ◽

Leaf Tissue ◽

Cell Number ◽

Cell Ultrastructure ◽

Response To Treatment ◽

Prominent Symptom ◽

Chlorophylls A And B ◽

Cell Dimensions ◽

Structure And Ultrastructure

Coronatine is a non-host-specific phytotoxin produced by several members of the Pseudomonas syringae group of pathovars. The toxin acts as a virulence factor in P. syringae pv. tomato, allowing the organism to multiply to a higher population density and develop larger lesions than mutant strains unable to produce the toxin. The most prominent symptom observed in leaf tissue treated with coronatine is an intense spreading chlorosis; this has been attributed to a loss of chlorophylls a and b in tobacco. Coronatine's effects on membrane integrity and cell ultrastructure have not been previously investigated. The present study describes changes in tomato leaves in response to treatment with purified coronatine, infection by a coronatine-producing strain of P. syringae pv. tomato, and infection by a cor" mutant.In contrast to H2O-treated tissue, coronatine-treated tissue showed a diffuse chlorosis extending approximately 5 mm from the inoculation site. Leaf thickness, cell number, and cell dimensions were similar for both healthy and coronatine-treated, chlorotic tissue; however, the epidermal cell walls were consistently thicker in coronatine-treated leaves (Figs, la and lb).

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Banded aggregates containing fibrillin are present in the cartilage matrix adjacent to chondrocytes in individuals affected with scoliosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124860 ◽

1992 ◽

Vol 50 (1) ◽

pp. 892-893

Author(s):

Douglas R. Keene ◽

Magaret Fairhurst ◽

Catherine C. Ridgway ◽

Lynn Y. Sakai

Keyword(s):

Connective Tissue ◽

Marfan Syndrome ◽

Cross Section ◽

Immunoelectron Microscopy ◽

Cartilage Matrix ◽

Negative Stain ◽

Gene Coding ◽

Rotary Shadowing

Matrix microfibrils are present in the connective tissue matrices of all tissues. Following standard TEM processing, they appear in cross section as cylindrical fibrils 8-10 nm in diameter, often associated with amorphous elastin. They are also seen in the absence of amorphous elastin, for example in the shallow papillary layer of skin, and also in cartilage matrix (Figure 1). Negative stain and rotary shadowing studies suggest that microfibrils are composed of laterally associated globular structures connected by fine filamentous strands (“ beaded strings”), and that they are extendable. Immunoelectron microscopy has demonstrated that fibrillin, a 350 Kd glycoprotein, is distributed along all microfibrils with a relaxed periodicity of about 54 nm The gene coding for fibrillin has recently been identified and is defective in the Marfan syndrome.

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