Abstract
Flowering is regulated by endogenous factors and by environmental stimuli such as light and temperature.
COP1 in A. thaliana is a gene that is involved in photomorphogenesis. The cop1 mutants show light independent morphogenesis. The weak allele, cop1-6 mutation causes early flowering in LD and SD. To elucidate the mechanism of early flowering in cop1-6, the double mutants of cop1-6 with one of several late-flowering mutations (cry2, gi, co and ld) were constructed and their flowering characteristics were examined. All of the double mutants except cry2-1 cop1-6 flowered later than cop1-6 single, demonstrating that cop1-6 is epistatic to cry2-1 for early flowering. The relative increase in the number of leaves was higher in co-1 cop1-6 plants than in co-1 plants, whereas the delay in flowering of gi-2 cop1-6 plants was almost the same as that in gi-2 plants.
