Regulation of flowering time by light quality.
The transition to flowering in plants is regulated by environmental factors such as temperature and light. Plants grown under dense canopies or at high density perceive a decrease in the ratio of red to far-red incoming light. This change in light quality serves as a warning of competition, triggering a series of responses known collectively as the 'shade-avoidance syndrome'. During shade avoidance, stems elongate at the expense of leaf expansion, and flowering is accelerated. Of the five phytochromes-a family of red/far-red light photoreceptors-in Arabidopsis, phytochrome B (phyB) has the most significant role in shade-avoidance responses, but the mechanisms by which phyB regulates flowering in response to altered ratios of red to far-red light are largely unknown. Here we identify PFT1 (PHYTOCHROME AND FLOWERING TIME 1), a nuclear protein that acts in a phyB pathway and induces flowering in response to suboptimal light conditions. PFT1 functions downstream of phyB to regulate the expression of FLOWERING LOCUS T (FT), providing evidence for the existence of a light-quality pathway that regulates flowering time in plants.
Cerdán
Pablo D
PD
Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
Chory
Joanne
J
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D004843:Epistasis, Genetic; D035264:Flowers / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*; D018506:Gene Expression Regulation, Plant; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010786:Photoreceptor Cells; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism; D051942:Phytochrome A; D051939:Phytochrome B; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics
D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; C418905:FT protein, Arabidopsis; D009687:Nuclear Proteins; C475686:PFT1 protein, Arabidopsis; C497973:PHYA protein, Arabidopsis; C497952:PHYB protein, Arabidopsis; D051942:Phytochrome A; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors; D010834:Phytochrome; D051939:Phytochrome B