The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease

Agrobacterium radiobacter K84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of A. tumefaciens. More than 2,000 transposon insertion derivatives of strain K84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocon...

Full description

Bibliographic Details
Main Authors: Penyalver, Ramón, Oger, Phil M., Su, Shengchang, Álvarez, Belén, Salcedo, Carmina I., López, María M., Farrand, Stephen K.
Format: article
Language:Inglés
Published: 2017
Online Access:http://hdl.handle.net/20.500.11939/4352
_version_ 1855032106283958272
author Penyalver, Ramón
Oger, Phil M.
Su, Shengchang
Álvarez, Belén
Salcedo, Carmina I.
López, María M.
Farrand, Stephen K.
author_browse Farrand, Stephen K.
López, María M.
Oger, Phil M.
Penyalver, Ramón
Salcedo, Carmina I.
Su, Shengchang
Álvarez, Belén
author_facet Penyalver, Ramón
Oger, Phil M.
Su, Shengchang
Álvarez, Belén
Salcedo, Carmina I.
López, María M.
Farrand, Stephen K.
author_sort Penyalver, Ramón
collection ReDivia
description Agrobacterium radiobacter K84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of A. tumefaciens. More than 2,000 transposon insertion derivatives of strain K84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocontrol. Three mutants affected in biocontrol properties were identified. All three mutants displayed normal levels of attachment to tomato seed and root colonization. One of these mutants, M19-164, exhibited partial biocontrol and did not produce detectable levels of agrocin 84. In this mutant, the transposon is located in the agn locus of pAgK84, which codes for agrocin 84 biosynthesis. The second mutant, M19-158, also exhibited partial biocontrol and produced reduced amounts of agrocin 84 as a result of a mutation in a chromosomal gene of unknown function. The third mutant, M9-22, failed to biocontrol, was impaired in both growth in minimal medium and siderophore production, and failed to produce detectable levels of agrocin 84. The chromosomal gene ahcY, which encodes S adenosyl-L-homocysteine hydrolase, was disrupted in this mutant. Expression of a functional copy of ahcY in M9-22 restored all of the altered phenotypes. The fact that all identified biocontrol mutants exhibited a partial or total defect in production of agrocin 84 indicates that this antibiotic is required for optimum biocontrol. This study also identified two chromosomally encoded genes required for agrocin 84 production. That a mutation in ahcY abolishes biocontrol suggests that the intracellular ratio of S-adenosyl-L-methionine to S-adenosyl-L-homocysteine is an important factor for agrocin 84 biosynthesis. Finally, we demonstrate that the ahcY gene in strain K84 is also required for optimal growth as well as for antibiotic production and biocontrol of crown gall disease.
format article
id ReDivia4352
institution Instituto Valenciano de Investigaciones Agrarias (IVIA)
language Inglés
publishDate 2017
publishDateRange 2017
publishDateSort 2017
record_format dspace
spelling ReDivia43522025-04-25T14:42:56Z The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease Penyalver, Ramón Oger, Phil M. Su, Shengchang Álvarez, Belén Salcedo, Carmina I. López, María M. Farrand, Stephen K. Agrobacterium radiobacter K84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of A. tumefaciens. More than 2,000 transposon insertion derivatives of strain K84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocontrol. Three mutants affected in biocontrol properties were identified. All three mutants displayed normal levels of attachment to tomato seed and root colonization. One of these mutants, M19-164, exhibited partial biocontrol and did not produce detectable levels of agrocin 84. In this mutant, the transposon is located in the agn locus of pAgK84, which codes for agrocin 84 biosynthesis. The second mutant, M19-158, also exhibited partial biocontrol and produced reduced amounts of agrocin 84 as a result of a mutation in a chromosomal gene of unknown function. The third mutant, M9-22, failed to biocontrol, was impaired in both growth in minimal medium and siderophore production, and failed to produce detectable levels of agrocin 84. The chromosomal gene ahcY, which encodes S adenosyl-L-homocysteine hydrolase, was disrupted in this mutant. Expression of a functional copy of ahcY in M9-22 restored all of the altered phenotypes. The fact that all identified biocontrol mutants exhibited a partial or total defect in production of agrocin 84 indicates that this antibiotic is required for optimum biocontrol. This study also identified two chromosomally encoded genes required for agrocin 84 production. That a mutation in ahcY abolishes biocontrol suggests that the intracellular ratio of S-adenosyl-L-methionine to S-adenosyl-L-homocysteine is an important factor for agrocin 84 biosynthesis. Finally, we demonstrate that the ahcY gene in strain K84 is also required for optimal growth as well as for antibiotic production and biocontrol of crown gall disease. 2017-06-01T10:09:54Z 2017-06-01T10:09:54Z 2009 JUN 2009 article Penyalver, R., Oger, P. M., Su, S., Alvarez, B., Salcedo, C. I., Lopez, M. M. et al. (2009). The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease. Molecular Plant-Microbe Interactions, 22(6), 713-724. 0894-0282 http://hdl.handle.net/20.500.11939/4352 10.1094/MPMI-22-6-0713 en openAccess Impreso
spellingShingle Penyalver, Ramón
Oger, Phil M.
Su, Shengchang
Álvarez, Belén
Salcedo, Carmina I.
López, María M.
Farrand, Stephen K.
The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title_full The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title_fullStr The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title_full_unstemmed The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title_short The S-Adenosyl-L-Homocysteine Hydrolase Gene ahcY of Agrobacterium radiobacter K84 Is Required for Optimal Growth, Antibiotic Production, and Biocontrol of Crown Gall Disease
title_sort s adenosyl l homocysteine hydrolase gene ahcy of agrobacterium radiobacter k84 is required for optimal growth antibiotic production and biocontrol of crown gall disease
url http://hdl.handle.net/20.500.11939/4352
work_keys_str_mv AT penyalverramon thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT ogerphilm thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT sushengchang thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT alvarezbelen thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT salcedocarminai thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT lopezmariam thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT farrandstephenk thesadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT penyalverramon sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT ogerphilm sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT sushengchang sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT alvarezbelen sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT salcedocarminai sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT lopezmariam sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease
AT farrandstephenk sadenosyllhomocysteinehydrolasegeneahcyofagrobacteriumradiobacterk84isrequiredforoptimalgrowthantibioticproductionandbiocontrolofcrowngalldisease