Table 1.

Description of genes mutant in this experiment with their classical pathway designation

GenePathwayEffect on flowering time
FVE*AutonomousPos. regulator that suppresses FLC expression
HUA2*,AutonomousNeg. regulator that enhances late flowering in FRI functionals
LD*AutonomousPos. regulator that suppresses FLC expression
FT*IntegratorFlorigen integrating all pathways to activate floral meristem genes
TFL2*IntegratorFloral meristem identity; maintains high FLC despite brief warmth
GAI*HormonePos. regulator by up-regulating FT and gibberellin synthesis
SPY*HormoneNeg. regulator downstream of GAI that suppresses gibberellin
CO*PhotoperiodSensor of inductive long days, downstream of PHYs
CRY1*PhotoperiodPos. regulator of CO; perceives blue light of long days
GI*PhotoperiodIntegrates circadian clock information to perceive long days
PHYA*PhotoperiodPos. regulator of CO; perceives red light of long days
PHYB*PhotoperiodNeg. regulator of CO; perceives red:far-red ratio of light of long day
PHYD*PhotoperiodNeg. regulator of CO; obligately interacts with PHYB
PHYE*PhotoperiodNeg. regulator of CO; obligately interacts with PHYB
FRLVernalizationConstituent of FRI activation complex; up-regulates FLC
FRIVernalizationActivates FLC, conferring vernalization requirement
FLCVernalizationFT repressor that is epigenetically down-regulated by vernalization
VIN3VernalizationRequired for vernalization response in FRI:FLC functionals
  • Pathways are not exclusive since some genes act in multiple pathways simultaneously. Some mutant genotypes harbored multiple mutations. For example, phyabde is a quadruple mutant with LoF in PHYA, PHYB, PHYD, and PHYE. Neg., negative; Pos., positive.

  • * Mutations in this gene were not combined with any natural allele.

  • Mutations in this gene were induced in a background with a functional FRI allele introgressed from the Sf-2 ecotype.

  • Natural alleles only by introgressing a functional Sf-2 version without induced mutation.