Assessment of transformability of bacteria associated with tomato and potato plants

• Published in: Environmental biosafety research Vol. 6; no. 1-2; pp. 85 - 89
• Main Authors: van Overbeek, Leo, Ray, Jessica, van Elsas, Jan Dirk
• Format: Journal Article
• Language: English
• Published: France EDP Sciences 01.01.2007; Cambridge University Press
• Subjects: Acinetobacter; Acinetobacter - genetics; Agricultural land; Bacteria; Bacteria - genetics; bacterial endophytes; Biointeracties and Plant Health; Deoxyribonucleic acid; DNA; Experiments; Flowers & plants; Genes; Genomes; homologous recombination; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Lycopersicon esculentum - microbiology; plant-associated bacteria; Plasmids - genetics; Polymerase Chain Reaction; Potatoes; PRI Biointeractions en Plantgezondheid; Pseudomonas; Pseudomonas fragi; Ralstonia; Solanum tuberosum; Solanum tuberosum - genetics; Solanum tuberosum - microbiology; Sperm; Stems; Tomatoes; transformation; Transformation, Bacterial
• ISSN: 1635-7922; 1635-7930
• DOI: 10.1051/ebr:2007030

Transformation of plant-associated bacteria by plant DNA has never been demonstrated in agricultural fields. In total 552 bacterial isolates from stems of Ralstonia solanacearum-infected and healthy tomato plants and from stems and leaves of healthy potato plants were tested for natural genetic competence using plasmid pSKTG DNA and homologous DNA extracts. Control strain Acinetobacter baylyi ADP1 was transformable with both DNA extracts. No transformable isolates were observed after treatment with plasmid pSKTG DNA. Two isolates, P34, identified as Pseudomonas trivialis and A19, identified as Pseudomonas fragi, were selected on the basis of the consistently higher Rp-resistant CFU numbers after treatment with DNA from Rp-resistant cells than with that from wild-type cells. P34 showed 2.1-fold and A19 1.5-fold higher Rp-resistant CFU numbers after treatment with DNA from homologous Rp-resistant cells versus that from wild-type cells. It is concluded that bacteria capable of in vitro capture and integration of exogenous DNA into their genomes are relatively rare in culturable bacterial communities associated with tomato and potato plants, or that conditions conducive to transformation were not met in transformation assays.