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Updated: May 2, 2026

Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean
Published on: December 23, 2017
Clavibacter michiganensis subsp. phaseoli subsp. nov., pathogenic in bean
Ana J González1, Estefanía Trapiello1
1Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Principado de Asturias, 33300 Villaviciosa, Spain.
Abstract:
A yellow Gram-reaction-positive bacterium isolated from bean seeds (Phaseolus vulgaris L.) was identified as Clavibacter michiganensis by 16S rRNA gene sequencing. Molecular methods were employed in order to identify the subspecies. Such methods included the amplification of specific sequences by PCR, 16S amplified rDNA restriction analysis (ARDRA), RFLP and multilocus sequence analysis as well as the analysis of biochemical and phenotypic traits including API 50CH and API ZYM results. The results showed that strain LPPA 982T did not represent any known subspecies of C. michiganensis. Pathogenicity tests revealed that the strain is a bean pathogen causing a newly identified bacterial disease that we name bacterial bean leaf yellowing. On the basis of these results, strain LPPA 982T is regarded as representing a novel subspecies for which the name Clavibacter michiganensis subsp. phaseoli subsp. nov. is proposed. The type strain is LPPA 982T (=CECT 8144T=LMG 27667T).
Insights
A novel bacterium causing bacterial bean leaf yellowing was identified in bean seeds. This new pathogen, Clavibacter michiganensis subsp. phaseoli, represents a distinct subspecies affecting Phaseolus vulgaris.
Area of Science:
- Plant Pathology
- Bacteriology
- Molecular Biology
Background:
- Clavibacter michiganensis is a known plant pathogen.
- Accurate identification of bacterial pathogens is crucial for disease management.
Purpose of the Study:
- To identify and characterize a novel bacterial pathogen isolated from bean seeds.
- To determine if the isolate represents a known or new subspecies of Clavibacter michiganensis.
Main Methods:
- 16S rRNA gene sequencing for initial identification.
- Polymerase Chain Reaction (PCR), Amplified Ribosomal DNA Restriction Analysis (ARDRA), Restriction Fragment Length Polymorphism (RFLP), and Multilocus Sequence Analysis (MLSA) for subspecies identification.
- Biochemical and phenotypic analyses using API 50CH and API ZYM.
- Pathogenicity tests on bean plants (Phaseolus vulgaris L.).
Main Results:
- The isolated bacterium was identified as Clavibacter michiganensis.
- Molecular and phenotypic analyses indicated that the strain (LPPA 982T) did not match any known subspecies.
- Pathogenicity tests confirmed the strain causes a new disease in beans, termed bacterial bean leaf yellowing.
- The strain was proposed as a new subspecies, Clavibacter michiganensis subsp. phaseoli subsp. nov.
Conclusions:
- A novel subspecies of Clavibacter michiganensis, C. michiganensis subsp. phaseoli, has been identified.
- This subspecies is a pathogen of Phaseolus vulgaris, causing bacterial bean leaf yellowing.
- The findings contribute to understanding bacterial plant diseases and pathogen diversity.
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