Table 4.
Comparison of different water parameters in SP and CL plants containing similar concentrations of SO4 2–+PO4 3– or Cl– anions. respectively (~33mM)
| Leaf Ψπ (–MPa) | Leaf WC (%) | Leaf succulence (mg H2O cm–2) | WUE (g FW ml–1) | Water consumed (mL H2O g FW–1 d–1) | Water saving (transpiration, %) | Water saving (consume, %) | |
|---|---|---|---|---|---|---|---|
| SP 2.5 mM | 1.68±0.02 b | 88.1±0.9 b | 14.34±0.68 | 0.026±0.001 b | 1.91±0.13 a | 4.6±1.7 b | 8.1±0.8 b |
| CL 1 mM | 1.79±0.02 a | 90.2±0.3 a | 15.47±0.66 | 0.032±0.001 a | 1.54±0.07 b | 12.4±1.6 a | 19.2±2.0 a |
| P-value | * | * | ns | * | * | * | ** |
Different external concentrations of Cl– (CL) or sulphate+phosphate (SP) salt supplements were applied to obtain plants with comparable leaf internal concentrations of Cl– and SO4 2–+PO4 3– anions (see Supplementary Fig. S6 at JXB online for more information). We distinguished two different water saving parameters: water saving calculated from whole-plant water consumption (measured gravimetrically) and water saving from leaf transpiration (obtained from the ‘detached fresh weight loss’ assay shown in Fig. 6A). Both parameters were calculated as the water loss of BS plants minus the water loss of treated plants.
Ψπ, leaf osmotic potential; WC, water content; WUE, water-use efficiency.
Mean values ± SE, n=4–6. Levels of significance: P>0.05 (‘ns’, non-significant differences), *P≤0.05 and **P<0.01. ‘Homogeneous group’ statistics were calculated through ANOVA test.