ISHS Acta Horticulturae 489: VIII International Workshop on Fire Blight
THERMOREGULATION OF VIRULENCE GENE EXPRESSION IN THE FIRE BLIGHT PATHOGEN ERWINIA AMYLOVORA |
| Authors: | C. Goyer, M. Ullrich |
| Keywords: | temperature, environmental factors, apple, pear, plant disease |
| Abstract:
Thermoregulation of genes in the fire blight pathogen Erwinia amylovora was investigated by mutagenesis using the miniTn5 transposon which facilitates the identification of promotor fusions expressing the reporter gene (uidA) for glucuronidase. Most mutants showed similar glucuronidase activity at 18°C and 28°C on minimal medium plates containing X-Gluc. A few mutants (3.5%) were unique in their expression of glucuronidase activity predominantly at either 18°C (190 mutants) or 28°C (56 mutants) which indicated that the transposon was inserted under the control of a thermoregulated promoter. Temperature-dependent mutants were further screened using a more sensitive fluorometric assay for glucuronidase activity. Some mutants produced three to ten times more glucuronidase at either 18°C or 28°C, respectively. | |
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