Table 2.
Chemotactic responses of P. fluorescens Pf0-1 to plant-associated compounds
| Compoundsa | Chemotactic responsesb |
|---|---|
| l-(−)-malic acid | + + + |
| d-(+)-malic acid | − |
| fumaric acid | + + |
| maleic acid | − |
| succinic acid | + + |
| oxaloacetic acid | + |
| trans-aconitic acid | − |
| citric acid | + |
| acetic acid | − |
| benzoic acid | − |
| o-hydroxy benzoic acid | − |
| m-hydroxy benzoic acid | − |
| p-hydroxy benzoic acid | − |
| l-pyroglutamic acid | − |
| phenoxyacetic acid | − |
| syringic acid | − |
| protocatechuic acid | − |
| d-(−)-quinic acid | − |
| trans-ferulic acid | − |
| shikimic acid | − |
| γ-aminobutyric acid | − |
| glucose | − |
| fructose | − |
| maltose | − |
| ribose | − |
| xylose | − |
| Serine | +++ |
| Cysteine | +++ |
a
Compounds other than trans-ferulic acid were used at a concentration of 5 mM. Trans-ferulic acid was provided as a saturated solution in 10 mM HEPES buffer (pH 7.0).
b
Videotape frames were analyzed at the initiation of observations and 1 min later. Normalized cell numbers were calculated by dividing the number of bacteria at 1 min by that at the initiation of observations. The value of the normalized cell number was represented by the symbols, as follows: + + + > 4; 4 ≥ + + > 2; 2 ≥ + > 1.5; 1.5 ≥ − > 0. Serine and cysteine were positive controls.