Table 1.
Root hydraulic conductivity of 14- to 17-d-old barley plants in response to HgCl2 and HgCl2/DTT treatment
| Root type | Hydraulic conductivity |
||
| Control | HgCl2 | HgCl2/DTT | |
| Seminal root | 100a (10.5±2.3) | 47.5±16.0b,e | 86.6±1.7d |
| Adventitious root | 100a (4.4±1.3) | 26.2±2.5c | 65.5±8.6b |
| Entire root system | 100a (17.7±4.6) | 25.6±15.0c,e | –/– |
Conductivity was determined through exudation experiments on individual seminal and adventitious roots or on the entire root system of plants. Exudation was measured in normal growth medium (control) and after transient (5 min) exposure of roots to 50 μM HgCl2, without (HgCl2) or with subsequent recovery (15 min) in 5 mM DTT (‘HgCl2/DTT’). Results are means ±SD of three or four root analyses expressed as a percentage of the control. Hydraulic conductivity (10−8 m s−1 MPa−1) of control plants is given in parenthesis. Different superscripts indicate significant differences (P<0.05); –/–, not tested.