The anthracnose resistance locus Co-4 of common bean is located on chromosome 3 and contains putative disease resistance-related genes.
Theor Appl Genet
; 109(4): 690-9, 2004 Aug.
Article
em En
| MEDLINE
| ID: mdl-15221144
The broadest based resistance to anthracnose of common bean ( Phaseolus vulgaris L.) is conferred by the Co-4 locus. We sequenced a bacterial artificial chromosome clone harboring part of the Co-4 locus of the bean genotype Sprite and assembled a single contig of 106.5 kb for functional annotation. This region contained five copies of the COK-4 gene that encodes for a serine threonine kinase protein previously mapped to the Co-4 locus and 19 novel genes with no similarity to any previously identified genes of common bean. Several putative genes of the Co-4 locus seemed to be expressed as they matched perfectly with bean expressed sequence tags. The expression of the COK-4 genes was assessed by reverse transcription (RT)-PCR, and a single 850-bp cDNA fragment was sequenced and compared with the genomic sequences of the COK-4 homologs. Although the COK-4 cDNA was isolated from a different bean cultivar, it showed high similarity (95%) to the exons of genes BA17 and BA21, suggesting that they were expressed. In a phylogenetic tree including all currently available Pto-like sequences from Phaseolus species, the COK-4 homologs formed a single cluster with the Pto gene, whereas two sequences from P. coccineus and all sequences of P. vulgaris formed two closely related clusters. The Co-4 locus was physically mapped to the short arm of bean chromosome 3, which corresponds to linkage group B8. This study represents a first step in gaining an understanding of the genomic organization of an anthracnose resistance locus of common bean and provides molecular data for comparative analysis with other plant species.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Filogenia
/
Doenças das Plantas
/
Ascomicetos
/
Phaseolus
/
Imunidade Inata
Idioma:
En
Revista:
Theor Appl Genet
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Alemanha