RNA gel-blot analyses of Arabidopsis HSP 70-3. Total RNA was isolated from 24-d-old leaves after exposure for 1 h to: 22°C and 100 μmol m−2 s−1 of light (ML), 27.5°C and 100 μmol m−2 s−1 of light (wML), 29°C and 1,000 μmol m−2 s−1 of light (HL), or 24°C and 1,000 μmol m−2 s−1 fHL. Twenty micrograms of total RNA was probed with HSP70-3 or β-tubulin (Btub).