Environmental Microbiology (2008) 10, 2455-2461

Faina Kamilova, Gerda Lamers and Ben Lugtenberg (2008)
Biocontrol strain Pseudomonas fluorescens WCS365 inhibits germination of Fusarium oxysporum spores in tomato root exudate as well as subsequent formation of new spores
Environmental Microbiology 10 (9), 2455-2461
Abstract: Fusarium oxysporum f. sp. radicis-lycopersici (Forl) is a soilborne pathogenic fungus which can cause tomato foot and root rot (TFRR). Tomato root exudate is a good source of nutrients for both Forl and the TFRR-suppressing biocontrol bacterium Pseudomonas fluorescens strain WCS365. Incubation of Forl microconidia in tomato root exudate stimulates their germination. This phenomenon is observed, to a lesser extent, upon incubation in plant nutrient solution supplemented with citrate or glucose, the major organic acid and sugar components, respectively, of tomato root exudate. Here we show that induction of germination of microconidia is significantly reduced in the presence of P. fluorescens WCS365 in all tested media. Scanning electron microscopy revealed that P. fluorescens WCS365 colonizes developing hyphae. Efficient colonization correlates with low nutrient availability. Eventually, new microconidia are formed. The presence of P. fluorescens WCS365 reduces the number of newly formed microconidia. This reduction does not depend on physical contact between bacteria and hyphae. We discuss that the ability of P. fluorescens WCS365 to slow down the processes of microconidia germination and development of new microconidia of the phytopathogen, and therefore the ability to reduce fungal dissemination, is likely to contribute to the biocontrol efficacy of this strain.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ben J.J. Lugtenberg

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium crown and root rot	Tomato (Solanum lycopersicum)
Pseudomonas fluorescens (antagonist)	Fusarium crown and root rot	Tomato (Solanum lycopersicum)
	Fusarium oxysporum