| Autor: |
Bakker PA; Institute of Biology, Utrecht University, Section of Plant Pathology, The Netherlands. P.A.H.M.Bakker@bio.uu.nl, Glandorf DC, Viebahn M, Ouwens TW, Smit E, Leeflang P, Wernars K, Thomashow LS, Thomas-Oates JE, van Loon LC |
| Jazyk: |
angličtina |
| Zdroj: |
Antonie van Leeuwenhoek [Antonie Van Leeuwenhoek] 2002 Aug; Vol. 81 (1-4), pp. 617-24. |
| DOI: |
10.1023/a:1020526126283 |
| Abstrakt: |
Pseudomonas putida WCS358r, genetically modified to have improved activity against soil-borne pathogens, was released into the rhizosphere of wheat. Two genetically modified derivatives carried the phz or the phl biosynthetic gene loci and constitutively produced either the antifungal compound phenazine-1-carboxylic acid (PCA) or the antifungal and antibacterial compound 2,4-diacetylphloroglucinol (DAPG). In 1997 and 1998, effects of single introductions of PCA producing derivatives on the indigenous microflora were studied. A transient shift in the composition of the total fungal microflora, determined by amplified ribosomal DNA restiction analysis (ARDRA), was detected. Starting in 1999, effects of repeated introduction of genetically modified microorganisms (GMMs) were studied. Wheat seeds coated with the PCA producer, the DAPG producer, a mixture of the PCA and DAPG producers, or WCS358r, were sown and the densities, composition and activities of the rhizosphere microbial populations were measured. All introduced strains decreased from 10(7) CFU per gram of rhizosphere sample to below the detection limit after harvest of the wheat plants. The phz genes were stably maintained in the PCA producers, and PCA was detected in rhizosphere extracts of plants treated with this strain or with the mixture of the PCA and DAPG producers. The phl genes were also stably maintained in the DAPG producing derivative of WCS358r. Effects of the genetically modified bacteria on the rhizosphere fungi and bacteria were analyzed by using amplified ribosomal DNA restriction analysis. Introduction of the genetically modified bacterial strains caused a transient change in the composition of the rhizosphere microflora. However, introduction of the GMMs did not affect the several soil microbial activities that were investigated in this study. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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