TABLE 2.
Root dry weight (DW), root/shoot ratio, total root length, root surface area, root number, root malondialdehyde (MDA) concentration, root electrolyte leakage (EL), and root relative water content (RWC) of rice under different treatments. Alleviation effects of Si on these parameters in rice under NaCl or PEG treatments.
| Parameter | Control | + Si | NaCl | NaCl + Si | PEG | PEG + Si |
Alleviation effect of Si |
|
| NaCl | PEG | |||||||
| Root DW (mg) | 81.1 ± 2.6a | 83.4 ± 4.1a | 46.1 ± 3.6d | 67.4 ± 4.0bc | 63.0 ± 3.0c | 74.7 ± 3.4ab | +26.2% | +14.5% |
| Root/shoot ratio (%) | 21.4 ± 1.1a | 21.8 ± 1.2a | 15.2 ± 0.5c | 18.3 ± 2.0b | 19.5 ± 0.7ab | 20.5 ± 2.0ab | +14.4% | +4.39% |
| Total length (cm) | 401 ± 31ab | 447 ± 57a | 196 ± 7d | 312 ± 33c | 279 ± 38c | 380 ± 18b | +31.3% | +25.2% |
| Surface area (cm2) | 29.3 ± 2.8a | 32.0 ± 3.7a | 10.4 ± 1.2d | 16.1 ± 0.4c | 17.1 ± 1.6c | 23.3 ± 2.1b | +19.5% | +21.2% |
| Root number | 333 ± 17ab | 407 ± 36a | 176 ± 20d | 267 ± 39b | 243 ± 16c | 326 ± 18b | +27.4% | +25.0% |
| MDA (nmol g–1 FW) | 7.59 ± 0.30c | 5.66 ± 0.37c | 16.9 ± 1.9a | 6.68 ± 1.29c | 11.4 ± 0.9b | 6.24 ± 0.68c | −160% | −67.9% |
| EL (%) | 41.4 ± 3.1c | 40.2 ± 1.3c | 67.4 ± 3.8a | 57.3 ± 3.1b | 57.1 ± 4.4b | 41.6 ± 1.2c | −24.3% | −37.7% |
| RWC (%) | 82.8 ± 1.3a | 81.7 ± 0.9a | 76.0 ± 0.8b | 81.7 ± 2.6a | 77.8 ± 1.2b | 83.5 ± 0.9a | +5.64% | +6.81% |
Rice seedlings were grown hydroponically with control, 100 mM NaCl (NaCl), and 18% (w/v) PEG-6000 (PEG) in the absence or presence (+ Si) of 1.5 mM Si for 5 days. Root growth parameters are shown as mean values ± SE of three independent biological replicates, and different letters indicate significant differences (P < 0.05). The alleviation effects of Si were calculated using mean values.