RNA gel-blot analysis to confirm microarray data. Lanes contained 10 μg of total RNA extracted from the different tissues after UV-B (+) and no UV-B (-) treatments. Several identical gels were prepared and blotted. Each blot was hybridized with 32P-labeled RuBisCO small subunit (a), ribosomal protein L11 (b) or cinnamyl alcohol dehydrogenase (c) probes. (d) Ethidium-bromide-stained gel as a check for equal loading. The log2 ratio was calculated as for microarray experiments by quantification of hybridization signals and ethidium-bromide-stained bands using Kodak ds 1D Digital Science, as described in Materials and Methods. The log2 ratio is provided at the bottom of each blot, using as a reference RNA from plants that were grown under natural levels of UV-B. ND means that the signal was too low for quantification.