Plant Physiology 60:723-729 (1977)
© 1977 American Society of Plant Biologists
Articles
Involvement of Phaseolotoxin in Halo Blight of Beans
Transport and Conversion to Functional Toxin
Robin E. Mitchell and
Roderick L. Bieleski
a Plant Diseases Division, Department of Scientific and Industrial Research, Private Bag, Auckland, New Zealand
Phaseolotoxin ([N -phosphosulfamyl]ornithylalanylhomoarginine) is produced by Pseudomonas phaseolicola (Burkh.) Dows. in liquid culture. When phaseolotoxin was applied to leaves of bean (Phaseolus vulgaris L.) at 0.1 to 1 nmoles/g fresh weight of leaf by a prick-assay procedure, the characteristic "halo" symptom of bean halo blight disease developed after 24 to 48 hours. At higher concentrations (10-100 nmoles/g fresh weight) the systemic symptoms, which are commonly a feature of diseased plants, also developed after 24 to 48 hours.
When applied to bean leaves, phaseolotoxin was rapidly broken down by the sequential removal of homoarginine and alanine. N -Phosphosulfamylornithine was the major product formed, although phosphosulfamate and unreacted phaseolotoxin were also present. When P. phaseolicola infected bean plants, very little phaseolotoxin was detected within the plant, but the amount of N -phosphosulfamylornithine formed was sufficient to account for the observed chlorosis, the ornithine accumulation, and the systemic symptoms. N -Phosphosulfamylornithine therefore seemed to be the main functional phytotoxin of bean halo blight disease.
When 35S-phaseolotoxin was applied to primary leaves, 35S (assumed to be a mixture of phaseolotoxin, N -phosphosulfamylornithine, and phosphosulfamate) was actively loaded into the fine veins of the leaf and moved through the plant in the vascular system at a speed greater than 3 cm/hour, particularly toward the apical and lateral buds and the root tips. Certain factors which affect pholem transport (arsenate, cold) affected toxin movement and the expression of systemic symptoms. Autoradiography suggested that the 35S was transported in the phloem.
A model for the involvement of phaseolotoxin in halo blight disease is presented.
This article has been cited by other articles:

|
 |

|
 |
 
L. A. Rigano, C. Payette, G. Brouillard, M. R. Marano, L. Abramowicz, P. S. Torres, M. Yun, A. P. Castagnaro, M. E. Oirdi, V. Dufour, et al.
Bacterial Cyclic {beta}-(1,2)-Glucan Acts in Systemic Suppression of Plant Immune Responses
PLANT CELL,
June 1, 2007;
19(6):
2077 - 2089.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Aguilera, K. Lopez-Lopez, Y. Nieto, R. Garciduenas-Pina, G. Hernandez-Guzman, J. L. Hernandez-Flores, J. Murillo, and A. Alvarez-Morales
Functional Characterization of the Gene Cluster from Pseudomonas syringae pv. phaseolicola NPS3121 Involved in Synthesis of Phaseolotoxin
J. Bacteriol.,
April 1, 2007;
189(7):
2834 - 2843.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Lopez-Lopez, J. L. Hernandez-Flores, M. Cruz-Aguilar, and A. Alvarez-Morales
In Pseudomonas syringae pv. phaseolicola, Expression of the argK Gene, Encoding the Phaseolotoxin-Resistant Ornithine Carbamoyltransferase, Is Regulated Indirectly by Temperature and Directly by a Precursor Resembling Carbamoylphosphate
J. Bacteriol.,
January 1, 2004;
186(1):
146 - 153.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. L. Bender, F. Alarcon-Chaidez, and D. C. Gross
Pseudomonas syringae Phytotoxins: Mode of Action, Regulation, and Biosynthesis by Peptide and Polyketide Synthetases
Microbiol. Mol. Biol. Rev.,
June 1, 1999;
63(2):
266 - 292.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. B. Langley, M. D. Templeton, B. A. Fields, R. E. Mitchell, and C. A. Collyer
Mechanism of Inactivation of Ornithine Transcarbamoylase by Ndelta -(N'-Sulfodiaminophosphinyl)-L-ornithine, a True Transition State Analogue?. CRYSTAL STRUCTURE AND IMPLICATIONS FOR CATALYTIC MECHANISM
J. Biol. Chem.,
June 23, 2000;
275(26):
20012 - 20019.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|