Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

The interaction between plant protecting pseudomonads and their crop plants

In diseased fields areas with healthy plants have been found. This is due to microorganisms that protect the plant from the pathogen. Research is being carried out with respect to the efficacy of these plant growth promoting (PGP) rhizobacteria. PGP Pseudomonas bacteria are being developed, primarily for tomato and sugar beet, by combining superior colonization genes and adhesion properties with optimal diacetylphloroglucinol (Phl) production.

Major amino acids of tomato exudate have been identified. Analyses of the sugar composition of sugar beet and tomato exudates have been initiated. It is expected that some of the mutants which are defective in utilization of exudate components will be inducible. The respective promoters would be candidates to engineer the production of Phl for biocontrol purposes. Genes involved in amino acid biosynthesis appear to be involved in rhizosphere colonization. Similarly, the oprF gene, encoding a bacterial cell surface protein, is involved in attachment of bacteria to the root surface. Screening of random mutants on defects in colonization has started. It is envisaged that colonization and attachment genes will be combined with genes engineered for optimal Phl production. Protocols are being developed for efficient coating of seeds with bacteria and for plant pathogen systems in which wild type and engineered PGP bacteria can be tested.

Reported by

Leiden University
Clusius Laboratory Wassenaarse weg 64
2333AL Leiden
Netherlands