Graft transmission of a floral stimulant derived from CONSTANS.
Photoperiod in plants is perceived by leaves and in many species influences the transition to reproductive growth through long-distance signaling. CONSTANS (CO) is implicated as a mediator between photoperiod perception and the transition to flowering in Arabidopsis. To test the role of CO in long-distance signaling, CO was expressed from a promoter specific to the companion cells of the smallest veins of mature leaves. This expression in tissues at the inception of the phloem translocation stream was sufficient to accelerate flowering at the apical meristem under noninductive (short-day) conditions. Grafts that conjoined the vegetative stems of plants with different flower-timing phenotypes demonstrated that minor-vein expression of CO is able to substitute for photoperiod in generating a mobile flowering signal. Our results suggest that a CO-derived signal(s), or possibly CO itself, fits the definition of the hypothetical flowering stimulant, florigen.
Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA.
Brian G
BG
Ayre
Robert
R
Turgeon
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D035264:Flowers / Q000502:physiology*; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000254:growth & development*; D018547:Plant Stems / Q000254:growth & development; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D016335:Zinc Fingers
D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D017931:DNA Primers; D004268:DNA-Binding Proteins; D018749:RNA, Plant; D011994:Recombinant Proteins; D014157:Transcription Factors; D005966:Glucuronidase