|De La Fuente, Leonardo|
Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2003
Publication Date: 8/1/2004
Citation: De La Fuente, L., Thomashow, L.S., Weller, D.M., Bajsa, N., Quagliotto, L., Cherin, L., Arias, A. 2004. Pseudomonas fluorescens up61 isolated from birdsfoot trefoil rhizosphere produces multiple antibiotics and exerts a broad spectrum of biocontrol activity. European Journal of Plant Pathology 110: 671-681. Interpretive Summary: Pseudomonas fluorescens UP61 constitutes the first report of a bacteria isolated from South American soils producing the antibiotics 2,4-diacetylphloroglucinol, pyrrolnitrin and pyoluteorin. Originally isolated from a forage legume (birdsfoot trefoil) grown in Uruguay, its bocontrol activity was shown in other crops such as beans and tomato. Its wide antagonistic activity against several phytopathogens in vitro, shows its potential to be used as a broad spectrum biocontrol agent. Molecular techniques showed that this strain is similar to other examples described in the literature that were isolated worldwide.
Technical Abstract: The efficient use of rhizospheric microorganisms to control plant pathogens has been reported worldwide in different plants. Pseudomonas fluorescens UP61 is a biocontrol strain isolated from the rhizosphere of Lotus corniculatus L. (birdsfoot trefoil) healthy plants from Uruguayan soils. This strain exhibited in vitro antagonistic activity against a broad spectrum of fungal and bacterial phytopathogens. It was shown to be an effective biocontrol agent in different hosts, reducing the disease incidence caused by Sclerotium rolfsii in beans and Rhizoctonia solani in tomato. P. fluorescens UP61 produces three antibiotics possibly involved in its biocontrol activity: 2,4-diacetylphloroglucinol, pyrrolnitrin and pyoluteorin. Molecular techniques such as 16S rDNA RFLP, RAPD and rep-PCR, and partial sequence of the phlD gene, revealed the similarity of UP61 with other biocontrol strains isolated worldwide that are able to produce these antibiotics.