title: Transcription Factor Interplay between LEAFY and APETALA1/CAULIFLOWER during Floral Initiation.
abstract: The transcription factors LEAFY (LFY) and APETALA1 (AP1), together with the AP1 paralog CAULIFLOWER (CAL), control the onset of flower development in a partially redundant manner. This redundancy is thought to be mediated, at least in part, through the regulation of a shared set of target genes. However, whether these genes are independently or cooperatively regulated by LFY and AP1/CAL is currently unknown. To better understand the regulatory relationship between LFY and AP1/CAL and to obtain deeper insights into the control of floral initiation, we monitored the activity of LFY in the absence of AP1/CAL function. We found that the regulation of several known LFY target genes is unaffected by AP1/CAL perturbation, while others appear to require AP1/CAL activity. Furthermore, we obtained evidence that LFY and AP1/CAL control the expression of some genes in an antagonistic manner. Notably, these include key regulators of floral initiation such asTERMINAL FLOWER1(TFL1), which had been previously reported to be directly repressed by both LFY and AP1. We show here thatTFL1expression is suppressed by AP1 but promoted by LFY. We further demonstrate that LFY has an inhibitory effect on flower formation in the absence of AP1/CAL activity. We propose that LFY and AP1/CAL act as part of an incoherent feed-forward loop, a network motif where two interconnected pathways or transcription factors act in opposite directions on a target gene, to control the establishment of a stable developmental program for the formation of flowers.
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Kevin
authors.identifier: http://orcid.org/0000-0003-0205-4013
authors.initials: K
authors.lastname: Goslin
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Beibei
authors.initials: B
authors.lastname: Zheng
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Antonio
authors.identifier: http://orcid.org/0000-0002-8828-1809
authors.initials: A
authors.lastname: Serrano-Mislata
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Liina
authors.identifier: http://orcid.org/0000-0002-0433-0475
authors.initials: L
authors.lastname: Rae
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Patrick T
authors.identifier: http://orcid.org/0000-0003-3544-670X
authors.initials: PT
authors.lastname: Ryan
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Kamila
authors.initials: K
authors.lastname: Kwaśniewska
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Bennett
authors.initials: B
authors.lastname: Thomson
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Diarmuid S
authors.identifier: http://orcid.org/0000-0002-3043-3750
authors.initials: DS
authors.lastname: Ó'Maoiléidigh
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Francisco
authors.identifier: http://orcid.org/0000-0001-7598-3003
authors.initials: F
authors.lastname: Madueño
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.); wellmerf@tcd.ie.|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and wellmerf@tcd.ie.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.) wellmerf@tcd.ie.
authors.forename: Frank
authors.identifier: http://orcid.org/0000-0002-2095-0981
authors.initials: F
authors.lastname: Wellmer
authors.affiliation: Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland (K.G., B.Z., L.R., P.T.R., K.K., B.T., D.S.Ó., F.W.).|Department of Biology, National University of Ireland Maynooth, Maynooth, Ireland (K.G., E.G.); and.|Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain (A.S.-M., F.M.).
authors.forename: Emmanuelle
authors.identifier: http://orcid.org/0000-0003-3548-8213
authors.initials: E
authors.lastname: Graciet
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C091535:AP1 protein, Arabidopsis; D029681:Arabidopsis Proteins; C091536:CAL protein, Arabidopsis; C074747:LFY protein, Arabidopsis; D026161:MADS Domain Proteins; D014157:Transcription Factors