Table 1.
The pretreatments and treatments applied to detached sorghum root segments cultivated ex planta
| Treatment ID | Segment pretreatment | Compositiona |
|---|---|---|
| Si+ 1 mMb | Sodium silicate 1 mmol dm−3 | |
| Si+ 2 mM | Sodium silicate 2 mmol dm−3 | |
| Si+ 2 mM sucrose | Sodium silicate 2 mmol dm−3, sucrose 1% (w/v) | |
| Si− | NaCl 1 mmol dm−3 | |
| Removed cortex | Rhizodermis and cortical tissues peeled-off mechanically | Sodium silicate 1 mmol dm−3 |
| Liquid nitrogen | Segments kept in liquid nitrogen for 5 min | Sodium silicate 1 mmol dm−3 |
| DNPc | Sodium silicate 1 mmol dm−3, 2,4-dinitrophenol 0.01 or 0.05 mmol dm−3 | |
| Low temperaturec | Erlenmeyer flask with the segments cultivated in ice-filled Styrofoam box (temperature 2–4 °C) | Sodium silicate 1 mmol dm−3 |
| Sucroseb | Sodium silicate 1 mmol dm−3, Sucrose 1% (w/v) | |
| Arabinoseb | Sodium silicate 1 mmol dm−3, arabinose 1% (w/v) | |
| ATP | Sodium silicate 1 mmol dm−3, ATP 1 or 5 mmol dm−3 | |
| Brefeldin Ab | Sodium silicate 1 mmol dm−3, 0.01% ethanol (v/v), brefeldin A 1, 5 or 10 µmol dm−3 | |
| SHAMb | Sodium silicate 1 mmol dm−3, salicylhydroxamic acid 0.2 or 2 mmol dm−3 | |
| KIb | Sodium silicate 1 mmol dm−3, potassium iodide 0.5 or 5 mmol dm−3 | |
| Ascorbic acidb | Sodium silicate 1 mmol dm−3, ascorbic acid 1 or 5 mmol dm−3 | |
| Ferulic acidb | Sodium silicate 1 mmol dm−3, ferulic acid 0.05 or 0.2 mmol dm−3 | |
| H2O2b | Sodium silicate 1 mmol dm−3, hydrogen peroxide 1 mmol dm−3 | |
| H2O2 pretreatment | Segments cultivated in distilled water supplied with 5 mmol dm−3 H2O2 for 8h (dark, constant 60 rpm shaking) | Sodium silicate 1 mmol dm−3 |
| Ethanolb | Sodium silicate 1 mmol dm−3, 0.01% ethanol (v/v) |
a Final concentration of the substance in distilled water.
b Treatments analysed by Raman spectroscopy and SEM-EDX for modelling the contributions of cell wall components to silica deposition.
c After 4 h cultivation the segments were either collected immediately, or they were rinsed in distilled water for 10 min and cultured for additional 68 h in Si+ medium.