Pseudomonas solanacearum genes controlling both pathogenicity on tomato and hypersensitivity on tobacco are clustered.

AUTOR(ES)

Boucher, C A

RESUMO

A pLAFR3 cosmid clone designated pVir2 containing a 25-kilobase (kb) DNA insert was isolated from a wild-type Pseudomonas solanacearum GMI1000 genomic library. This cosmid was shown to complement all but one of the nine Tn5-induced mutants which have been isolated after random mutagenesis and which have lost both pathogenicity toward tomato and ability to induce hypersensitive reaction (HR) on tobacco (hrp mutants). The insert is colinear with the genome and provides restoration of the HR-inducing ability when transferred into several Tn5-induced hrp mutants, but failed to complement deletion mutants extending on both sides of the pVir2 region. Localized mutagenesis demonstrated that the hrp genes are clustered within a 17.5-kb region of pVir2 and that this cluster probably extends on the genomic region adjacent to the pVir2 insert. A 3-kb region adjacent to the hrp cluster modulates aggressiveness toward tomato but does not control HR-inducing ability. Sequences within the hrp cluster of pVir2 have homology with the genomic DNA of Xanthomonas campestris strains representing eight different pathovars, suggesting that a set of common pathogenicity functions could be shared by P. solanacearum and X. campestris.

Documentos Relacionados

• Resistance, regulatory and production genes for the antibiotic methylenomycin are clustered.
• Mutants of Ralstonia (Pseudomonas) solanacearum sensitive to antimicrobial peptides are altered in their lipopolysaccharide structure and are avirulent in tobacco.
• Human metallothionein genes are clustered on chromosome 16.
• Interaction of Pseudomonas solanacearum with Suspension-Cultured Tobacco Cells and Tobacco Leaf Cell Walls In Vitro
• Gene Cluster of Pseudomonas syringae pv. “phaseolicola” Controls Pathogenicity of Bean Plants and Hypersensitivity on Nonhost Plants