| Autor: |
Miché, Lucie, Belkin, Shimshon, Rozen, Rachel, Balandreau, Jacques |
| Předmět: |
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| Zdroj: |
Environmental Microbiology; May2003, Vol. 5 Issue 5, p403-411, 9p |
| Abstrakt: |
Summary A set of Escherichia coli sensor strains was used to evaluate the stress exerted on surrounding bacteria by germinating rice seed exudates. These biosensor strains contain Vibrio fischeri luxCDABE genes fused to the promoters of different genes involved in bacterial responses to environmental stresses. They provided clear evidence for a stress exerted by rice exudates, as shown by the induction of the universal stress protein gene usp A as well as genes of the heat shock regulon, grp E, lon and dnaK. The oxidative stress gene kat G, and the post-transcriptional ompF regulator encoded by micF were also activated. The lack of derepression of rec A, uvr A and alk A indicated that damage to the DNA was not induced in the E. coli strains tested. Interestingly, resorcinolic lipids extracted from rice root seedlings induced the same promoters as whole exudates, suggesting that these compounds may contribute to the stress exerted by seedling exudates. The results obtained with E. coli biosensors thus indicate that, in vivo, exudates may also exert a selective pressure on root-colonizing bacteria. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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