Floral transition mutants in Arabidopsis

Abstract

An inventory of genetic differences in flowering time in Arabidopsis is presented and discussed. Many genes influence the transition to flowering in a quantitative way. Two groups of mutants and natural variants can be distinguished: those that are responsive to environmental factors and those that are less responsive or unresponsive. It is possible that all late/early-flowering mutants isolated to date carry a mutation with an effect, either promotive or repressive, on a floral repressor. The interaction between light perception and flowering has been studied by analysis of phytochrome- and cryptochrome-deficient mutants, which showed that phyA and probably also cryptochrome have a promotive role in flowering, whereas phyB and other stable phytochromes have an inhibitory role. A circadian rhythm is important in establishing daylength sensitivity, as was shown by the phenotype of the elf3 mutants.