Figure 6.

RNA gel-blot analysis to confirm microarray data. Lanes contained 10 μg of total RNA extracted from plants after different UV-B treatments. Several identical gels were prepared and blotted. Each blot was hybridized with ³²P-labeled elongation factor 1α (A), ribosomal protein QM (B), MRP33 (C), or MRP47 (D) probes. b, pl, Low flavonoid plants; B, Pl, high flavonoid and anthocyanin plants. Exclusion, Plants grown without UV-B in the field; Restoration, plants 1 d after removing the PE filters; Sunlight, plants grown under full sunlight. Figure 4E shows an 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,” and is provided at the bottom of each blot, using as a reference RNA from plants that were grown under natural levels of UV-B (listed as 0 change).