Gene expression in hemera mutants in red light condition

The hemera (hmr) mutant was identified as the first photomorphogenetic mutant with the combination of long hypocotyl and albino phenotypes in the light. Phytochrome-Interacting bHLH transcription Factors (PIFs), which are repressors of photomorphogenesis accumulate in darkness and are degraded in the light in a phytochrome-dependent manner. Two PIFs, PIF1 and PIF3 accumulated in the light in hmr mutants. In order to determine the gene expression of PIF-dependent genes in hmr mutants in the light, we have performed whole-genome expression analysis on two hmr mutants: a null allele, hmr-5; and a weak allele, hmr-22. Wild-type (Col-0) and hmr mutant seeds were surface-sterilized and plated on half-strength Murashige and Skoog (MS) growth medium without sucrose. The seeds were stratified in the dark at 4ºC for 4d. Seedlings were grown in constant red light (Rc, 10μmol/m2/s) at 21°C for 4d.