Early flowering phenotype of the Arabidopsis mutant is dependent on the FLOWERING LOCUS T-mediated pathway.

Controlling the flowering time is crucial for propagating plant species and crop production. () in encodes a putative carboxypeptidase, and an mutant () was found to cause highly pleiotropic phenotypes including a short plastochron, an enlarged shoot apical meristem, and reduced apical dominance. Although also shows an early flowering phenotype, its mechanism has not been investigated in detail. The most important floral integrator or florigen gene, (), has a close relative, (). In this report, we generated a new allele of using a genome-editing technique and produced double and triple mutants. The flowering time of was equally as late as under long-day conditions. In addition, the expression level of in was 2.4-fold higher than that in wild-type, even five days after germination under long-day conditions. These results suggest that the elevated expression level of is responsible for the early flowering phenotype of . Furthermore, expression of (), a negative regulator of expression, is severely repressed in , raising the possibility that low expression levels of contributes to upregulation of expression and the early flowering phenotype of .