Mapping And Characterization Of FLX Controlling Arabidiopsis Flowering Time

Control of Flowering time is one of the important physiological activities during the life cycle of plant. Molecular genetic studies on Arabidopsis thaliana revealed four main flowering controlling pathways: photoperiod, vernalization, autonomous, and gibberellin. Although extensive works have been done, the knowledge of flowering time control is also limited. We isolated a late-flowering Arabidopsis mutant, named FLX (Flowering Locus X). In this study, the Flowering control gene FLX was mapped. And the genetic pathway of the FLX in flowering control has been studied primarily.In order to mapping the FLX, homozygous flx plants (ecotype Columbia) were crossed with wild type plants (ecotype Landsberg), and the resulting F₁ plants were allowed to self-fertilize to generate F₂ population. Late-flowering plants in the F₂ population were selected for mapping. Both SSLP and CAPS markers were used to map this gene. The results showed that the FLX locus is located on 1649938 bp 1779950 bp chromosome 5.Meanwhile, the effect of the vernalization on mutant fix has been studied. The late-flowering phenotype of the mutant could be reversed by 30-day treatment of vernalization, which means that the FLX may participate in the vernalization pathway. Much higher level expression of the key gene FLC in mutant fix has been detected by RT-PCR. This result indicates the locus FLX may be on the upstream of the FLC in flowering control.