RNA gel-blot analysis to study the kinetics of UV-B induction of gene expression in adult leaves under experimental protocol 1. Lanes contained 10 μg of total RNA extracted from adult leaves after 2, 4, 6 and 8 h of UV-B (+) and no UV-B (-) treatments. Several identical gels were prepared and blotted. Each blot was hybridized with 32P-labeled clathrin (a) or ribosomal protein L11 (b) probes. (c) Ethidium-bromide-stained gel as a check for equal loading. Bars in gray indicate light treatment without UV-B; bars in white indicate light treatment with UV-B supplementation for the time indicated in the figure.