Table 2.2.1 Genes involved in the Arabidopsis flower development


                                            Gene Group

                                           Gene Subgroup

                                             Function

                                 Selected Members of the Subgroup

                                       Flowering Time Genes

                          Regulation by long-day period and light quality

                      Regulation of flowering by day period and light quality

                                  PHYA, PHYB, CRY2, GI, ELF3, CO

                                    Regulation by vernalization

                                  Induction of flowering by cold

                                            VRN2, VIN3

                                       Autonomous regulation

                  Induction of flowering independent of environmental conditions

                                      FCA, FY, FLD, FVE, FPA

                                      Regulation by hormones

                        Gibberellic acid-dependent regulation of flowering

                             GA1, FPF1, AtMYB33, EBS, PFT1, ABI1, ABI2

                                    Floral pathway integrators

              Integration of outputs from various flowering time regulation pathways

                                        FLC, SOC1, FT, LFY

                                      Meristem Identity Genes

                                   Shoot meristem identity genes

        Specification of the inflorescence apical meristem as indeterminate and non-floral

                                               TFL1

                                  Flower meristem identity genes

                              Specification of the meristem as floral

                                             LFY, AP1

                                    Floral Organ Identity Genes

                                                 A

         Specification of sepals in whorl 1, repression of class C genes in whorls 1 and 2

                                             AP1, AP2

                                                 B

                        Together with A, specification of petals in whorl 2

                                              AP3, PI

                                                 C

 Together with class B genes, specification of stamens in whorl 3, repression of A class genes in
   whorls 3 and 4 and specification of carpels in whorl 4; repression of meristem proliferation

                                                AG

                                                 D

                              Specification of ovules organ identity

                                          STK, SHP1, SHP2

                                                 E

    Co-operation with ABC genes in specification of petals, stamens and carpels in whorls 2-4,
                                       development of sepals

                                              SEP1-4